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Bibliography on: Paleontology Meets Genomics — Sequencing Ancient DNA

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Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 28 Feb 2020 at 01:47 Created: 

Paleontology Meets Genomics — Sequencing Ancient DNA

The ideas behind Jurassic Park have become real, kinda sorta. It is now possible to retrieve and sequence DNA from ancient specimens. Although these sequences are based on poor quality DNA and thus have many inferential steps (i,e, the resulting sequence is not likely to be a perfect replica of the living DNA), the insights to be gained from paleosequentcing are nonetheless great. For example, paleo-sequencing has shown that Neanderthal DNA is sufficiently different from human DNA as to be reasonably considered as coming from a different species.

Created with PubMed® Query: "ancient DNA" OR "ancient genome" OR paleogenetic OR paleogenetics NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

RevDate: 2020-02-26

Anonymous (2018)

On the use and abuse of ancient DNA.

Nature, 555(7698):559.

RevDate: 2020-02-26

Sirak KA, Fernandes DM, Cheronet O, et al (2020)

Human auditory ossicles as an alternative optimal source of ancient DNA.

Genome research pii:gr.260141.119 [Epub ahead of print].

DNA recovery from ancient human remains has revolutionized our ability to reconstruct the genetic landscape of the past. Ancient DNA research has benefited from the identification of skeletal elements, such as the cochlear part of the osseous inner ear, that provide optimal contexts for DNA preservation; however, the rich genetic information obtained from the cochlea must be counterbalanced against the loss of morphological information caused by its sampling. Motivated by similarities in developmental processes and histological properties between the cochlea and auditory ossicles, we evaluate the ossicles as an alternative source of ancient DNA. We demonstrate that ossicles perform comparably to the cochlea in terms of DNA recovery, finding no substantial reduction in data quantity and minimal differences in data quality across preservation conditions. Ossicles can be sampled from intact skulls or disarticulated petrous bones without damage to surrounding bone, and we argue that they should be utilized when available to reduce damage to human remains. Our results identify another optimal skeletal element for ancient DNA analysis and add to a growing toolkit of sampling methods that help to better preserve skeletal remains for future research while maximizing the likelihood that ancient DNA analysis will produce useable results.

RevDate: 2020-02-25

Anonymous (2018)

UK university strike, quark pioneer and the ancient-genome boom.

Nature, 555(7694):10-11.

RevDate: 2020-02-25

King T (2018)

Sex, power and ancient DNA.

Nature, 555(7696):307-308.

RevDate: 2020-02-25

Fernandes DM, Mittnik A, Olalde I, et al (2020)

The spread of steppe and Iranian-related ancestry in the islands of the western Mediterranean.

Nature ecology & evolution pii:10.1038/s41559-020-1102-0 [Epub ahead of print].

Steppe-pastoralist-related ancestry reached Central Europe by at least 2500 BC, whereas Iranian farmer-related ancestry was present in Aegean Europe by at least 1900 BC. However, the spread of these ancestries into the western Mediterranean, where they have contributed to many populations that live today, remains poorly understood. Here, we generated genome-wide ancient-DNA data from the Balearic Islands, Sicily and Sardinia, increasing the number of individuals with reported data from 5 to 66. The oldest individual from the Balearic Islands (~2400 BC) carried ancestry from steppe pastoralists that probably derived from west-to-east migration from Iberia, although two later Balearic individuals had less ancestry from steppe pastoralists. In Sicily, steppe pastoralist ancestry arrived by ~2200 BC, in part from Iberia; Iranian-related ancestry arrived by the mid-second millennium BC, contemporary to its previously documented spread to the Aegean; and there was large-scale population replacement after the Bronze Age. In Sardinia, nearly all ancestry derived from the island's early farmers until the first millennium BC, with the exception of an outlier from the third millennium BC, who had primarily North African ancestry and who-along with an approximately contemporary Iberian-documents widespread Africa-to-Europe gene flow in the Chalcolithic. Major immigration into Sardinia began in the first millennium BC and, at present, no more than 56-62% of Sardinian ancestry is from its first farmers. This value is lower than previous estimates, highlighting that Sardinia, similar to every other region in Europe, has been a stage for major movement and mixtures of people.

RevDate: 2020-02-25

Marcus JH, Posth C, Ringbauer H, et al (2020)

Genetic history from the Middle Neolithic to present on the Mediterranean island of Sardinia.

Nature communications, 11(1):939 pii:10.1038/s41467-020-14523-6.

The island of Sardinia has been of particular interest to geneticists for decades. The current model for Sardinia's genetic history describes the island as harboring a founder population that was established largely from the Neolithic peoples of southern Europe and remained isolated from later Bronze Age expansions on the mainland. To evaluate this model, we generate genome-wide ancient DNA data for 70 individuals from 21 Sardinian archaeological sites spanning the Middle Neolithic through the Medieval period. The earliest individuals show a strong affinity to western Mediterranean Neolithic populations, followed by an extended period of genetic continuity on the island through the Nuragic period (second millennium BCE). Beginning with individuals from Phoenician/Punic sites (first millennium BCE), we observe spatially-varying signals of admixture with sources principally from the eastern and northern Mediterranean. Overall, our analysis sheds light on the genetic history of Sardinia, revealing how relationships to mainland populations shifted over time.

RevDate: 2020-02-24

van Dorp L, Gelabert P, Rieux A, et al (2020)

Plasmodium vivax Malaria Viewed through the Lens of an Eradicated European Strain.

Molecular biology and evolution, 37(3):773-785.

The protozoan Plasmodium vivax is responsible for 42% of all cases of malaria outside Africa. The parasite is currently largely restricted to tropical and subtropical latitudes in Asia, Oceania, and the Americas. Though, it was historically present in most of Europe before being finally eradicated during the second half of the 20th century. The lack of genomic information on the extinct European lineage has prevented a clear understanding of historical population structuring and past migrations of P. vivax. We used medical microscope slides prepared in 1944 from malaria-affected patients from the Ebro Delta in Spain, one of the last footholds of malaria in Europe, to generate a genome of a European P. vivax strain. Population genetics and phylogenetic analyses placed this strain basal to a cluster including samples from the Americas. This genome allowed us to calibrate a genomic mutation rate for P. vivax, and to estimate the mean age of the last common ancestor between European and American strains to the 15th century. This date points to an introduction of the parasite during the European colonization of the Americas. In addition, we found that some known variants for resistance to antimalarial drugs, including Chloroquine and Sulfadoxine, were already present in this European strain, predating their use. Our results shed light on the evolution of an important human pathogen and illustrate the value of antique medical collections as a resource for retrieving genomic information on pathogens from the past.

RevDate: 2020-02-21

Guedes L, Borba VH, Camacho M, et al (2020)

African helminth infection out of Africa: paleoparasitological and paleogenetic investigations in Pretos Novos cemetery, Rio de Janeiro, Brazil (1769-1830).

Acta tropica pii:S0001-706X(19)30474-7 [Epub ahead of print].

Pretos Novos cemetery (PNC), Rio de Janeiro, Brazil (1769-1830) was created exclusively to bury enslaved Africans who died upon arrival at the city or before being sold in the slave market. The PNC site may be unique in the Americas in allowing the study of African parasite infections acquired in Africa. We aimed to identify parasites infecting PNC individuals through paleoparasitological and paleogenetic analyses. The bodies had been dismembered, placed in mass graves, and burned, and most human remains collected from the site are highly fragmented and show extensive degradation. Sacrum and pelvic sediments were collected from five individuals along with seven samples of sediment from other areas of the body, as controls. Samples were submitted to three parasitological techniques and, in paleogenetic analysis, to four molecular targets. Larvae, mites, pollen grains, and structure suggestive of plants and fungus were observed, but we found no evidence of helminth infection. Ascaris sp. cytb sequence was recovered in one individual. We emphasize that, even with the extensive degradation of PNC human remains and the process of curation of samples, it was possible to recover helminth aDNA. The origin of PNC individuals confirms that these infections were brought to Brazil from western and central Africa during the colonial era.

RevDate: 2020-02-19

Wu X, Ning C, Bao Q, et al (2019)

Mitochondrial Genome of an 8,400-Year-Old Individual from Northern China Reveals a Novel Subclade Under C5d.

Human biology, 91(1):21-30.

Ancient DNA studies have always refreshed our understanding of the human past that cannot be tracked by modern DNA alone. Until recently, ancient mitochondrial genomic studies in East Asia were still very limited. Here, we retrieved the whole mitochondrial genome of an 8,400-year-old individual from Inner Mongolia, China. Phylogenetic analyses show that the individual belongs to a previously undescribed clade under haplogroup C5d that most probably originated in northern Asia and may have a very low frequency in extant populations that have not yet been sampled. We further characterized the demographic history of mitochondrial haplogroups C5 and C5d and found that C5 experienced a sharp increase in population size starting around 4,000 years before present, the time when intensive millet farming was developed by populations who are associated with the Lower Xiajiadian culture and was widely adopted in northern China. We caution that people related to haplogroup C5 may have added this farming technology to their original way of life and that the various forms of subsistence may have provided abundant food sources and further contributed to the increase in population size.

RevDate: 2020-02-17

Harding T, Milot E, Moreau C, et al (2020)

Historical human remains identification through maternal and paternal genetic signatures in a founder population with extensive genealogical record.

American journal of physical anthropology [Epub ahead of print].

OBJECTIVES: We describe a method to identify human remains excavated from unmarked graves in historical Québec cemeteries by combining parental-lineage genetic markers with the whole-population genealogy of Québec contained in the BALSAC database.

MATERIALS AND METHODS: The remains of six men were exhumed from four historical cemeteries in the province of Québec, Canada. DNA was extracted from the remains and genotyped to reveal their mitochondrial and Y-chromosome haplotypes, which were compared to a collection of haplotypes of genealogically-anchored modern volunteers. Maternal and paternal genealogies were searched in the BALSAC genealogical record for parental couples matching the mitochondrial and the Y-chromosome haplotypic signatures, to identify candidate sons from whom the remains could have originated.

RESULTS: Analysis of the matching genealogies identified the parents of one man inhumed in the cemetery of the investigated parish during its operating time. The candidate individual died in 1833 at the age of 58, a plausible age at death in light of osteological analysis of the remains.

DISCUSSION: This study demonstrates the promising potential of coupling genetic information from living individuals to genealogical data in BALSAC to identify historical human remains. If genetic coverage is increased, the genealogical information in BALSAC could enable the identification of 87% of the men (n = 178,435) married in Québec before 1850, with high discriminatory power in most cases since >75% of the parental couples have unique biparental signatures in most regions. Genotyping and identifying Québec's historical human remains are a key to reconstructing the genomes of the founders of Québec and reinhuming archeological remains with a marked grave.

RevDate: 2020-02-13
CmpDate: 2020-02-13

Warren M (2019)

Move over, DNA: ancient proteins are starting to reveal humanity's history.

Nature, 570(7762):433-436.

RevDate: 2020-02-07

Pérez V, Cortés J, Marchant F, et al (2020)

Aquatic Thermal Reservoirs of Microbial Life in a Remote and Extreme High Andean Hydrothermal System.

Microorganisms, 8(2): pii:microorganisms8020208.

Hydrothermal systems are ideal to understand how microbial communities cope with challenging conditions. Lirima, our study site, is a polyextreme, high-altitude, hydrothermal ecosystem located in the Chilean Andean highlands. Herein, we analyze the benthic communities of three nearby springs in a gradient of temperature (42-72 °C represented by stations P42, P53, and P72) and pH, and we characterize their microbial diversity by using bacteria 16S rRNA (V4) gene metabarcoding and 16S rRNA gene clone libraries (bacteria and archaea). Bacterial clone libraries of P42 and P53 springs showed that the community composition was mainly represented by phototrophic bacteria (Chlorobia, 3%, Cyanobacteria 3%, at P42; Chlorobia 5%, and Chloroflexi 5% at P53), Firmicutes (32% at P42 and 43% at P53) and Gammaproteobacteria (13% at P42 and 29% at P53). Furthermore, bacterial communities that were analyzed by 16S rRNA gene metabarcoding were characterized by an overall predominance of Chloroflexi in springs with lower temperatures (33% at P42), followed by Firmicutes in hotter springs (50% at P72). The archaeal diversity of P42 and P53 were represented by taxa belonging to Crenarchaeota, Diapherotrites, Nanoarchaeota, Hadesarchaeota, Thaumarchaeota, and Euryarchaeota. The microbial diversity of the Lirima hydrothermal system is represented by groups from deep branches of the tree of life, suggesting this ecosystem as a reservoir of primitive life and a key system to study the processes that shaped the evolution of the biosphere.

RevDate: 2020-02-12

Turney CSM, Fogwill CJ, Golledge NR, et al (2020)

Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica.

Proceedings of the National Academy of Sciences of the United States of America pii:1902469117 [Epub ahead of print].

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice-climate feedbacks that further amplify warming.

RevDate: 2020-02-05

Macleod R, Sinding MS, Olsen MT, et al (2020)

DNA preserved in jetsam whale ambergris.

Biology letters, 16(2):20190819.

Jetsam ambergris, found on beaches worldwide, has always been assumed to originate as a natural product of sperm whales (Physeteroidea). However, only indirect evidence has ever been produced for this, such as the presence of whale prey remains in ambergris. Here, we extracted and analysed DNA sequences from jetsam ambergris from beaches in New Zealand and Sri Lanka, and sequences from ambergris of a sperm whale beached in The Netherlands. The lipid-rich composition of ambergris facilitated high preservation-quality of endogenous DNA, upon which we performed shotgun Illumina sequencing. Alignment of mitochondrial and nuclear genome sequences with open-access reference data for multiple whale species confirms that all three jetsam samples derived originally from sperm whales (Physeter macrocephalus). Shotgun sequencing here also provides implications for metagenomic insights into ambergris-preserved DNA. These results demonstrate significant implications for elucidating the origins of jetsam ambergris as a prized natural product, and also for the understanding of sperm whale metabolism and diet, and the ecological mechanisms underlying these coproliths.

RevDate: 2020-02-04

Xenikoudakis G, Ahmed M, Harris JC, et al (2020)

Ancient DNA reveals twenty million years of aquatic life in beavers.

Current biology : CB, 30(3):R110-R111.

Xenikoudakis et al. report a partial mitochondrial genome of the extinct giant beaver Castoroides and estimate the origin of aquatic behavior in beavers to approximately 20 million years. This time estimate coincides with the extinction of terrestrial beavers and raises the question whether the two events had a common cause.

RevDate: 2020-02-04

Tabares X, Zimmermann H, Dietze E, et al (2020)

Vegetation state changes in the course of shrub encroachment in an African savanna since about 1850 CE and their potential drivers.

Ecology and evolution, 10(2):962-979 pii:ECE35955.

Shrub encroachment has far-reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning.We document the compositional change and potential drivers for a northern Namibian Combretum woodland transitioning into a Terminalia shrubland. We use a multiproxy record (pollen, sedimentary ancient DNA, biomarkers, compound-specific carbon (δ13C) and deuterium (δD) isotopes, bulk carbon isotopes (δ13Corg), grain size, geochemical properties) from Lake Otjikoto at high taxonomical and temporal resolution.We provide evidence that state changes in semiarid environments may occur on a scale of one century and that transitions between stable states can span around 80 years and are characterized by a unique vegetation composition. We demonstrate that the current grass/woody ratio is exceptional for the last 170 years, as supported by n-alkane distributions and the δ13C and δ13Corg records. Comparing vegetation records to environmental proxy data and census data, we infer a complex network of global and local drivers of vegetation change. While our δD record suggests physiological adaptations of woody species to higher atmospheric pCO2 concentration and drought, our vegetation records reflect the impact of broad-scale logging for the mining industry, and the macrocharcoal record suggests a decrease in fire activity associated with the intensification of farming. Impact of selective grazing is reflected by changes in abundance and taxonomical composition of grasses and by an increase of nonpalatable and trampling-resistant taxa. In addition, grain-size and spore records suggest changes in the erodibility of soils because of reduced grass cover. Synthesis. We conclude that transitions to an encroached savanna state are supported by gradual environmental changes induced by management strategies, which affected the resilience of savanna ecosystems. In addition, feedback mechanisms that reflect the interplay between management legacies and climate change maintain the encroached state.

RevDate: 2020-01-31

De-Dios T, van Dorp L, Charlier P, et al (2020)

Metagenomic analysis of a blood stain from the French revolutionary Jean-Paul Marat (1743-1793).

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases pii:S1567-1348(20)30041-1 [Epub ahead of print].

The French revolutionary Jean-Paul Marat (1743-1793) was assassinated in 1793 in his bathtub, where he was trying to find relief from the debilitating skin disease he was suffering from. At the time of his death, Marat was annotating newspapers, which got stained with his blood and were subsequently preserved by his sister. We extracted and sequenced DNA from the blood stain and also from another section of the newspaper, which we used for comparison. Results from the human DNA sequence analyses were compatible with a heterogeneous ancestry of Marat, with his mother being of French origin and his father born in Sardinia. Metagenomic analyses of the non-human reads uncovered the presence of fungal, bacterial and low levels of viral DNA. Relying on the presence/absence of microbial species in the samples, we could cast doubt on several putative infectious agents that have been previously hypothesised as the cause of his condition but for which we detect not a single sequencing read. Conversely, some of the species we detect are uncommon as environmental contaminants and may represent plausible infective agents. Based on all the available evidence, we hypothesize that Marat may have suffered from a fungal infection (seborrheic dermatitis), possibly superinfected with bacterial opportunistic pathogens.

RevDate: 2020-01-29

Oswald JA, Allen JM, LeFebvre MJ, et al (2020)

Ancient DNA and high-resolution chronometry reveal a long-term human role in the historical diversity and biogeography of the Bahamian hutia.

Scientific reports, 10(1):1373 pii:10.1038/s41598-020-58224-y.

Quaternary paleontological and archaeological evidence often is crucial for uncovering the historical mechanisms shaping modern diversity and distributions. We take an interdisciplinary approach using multiple lines of evidence to understand how past human activity has shaped long-term animal diversity in an island system. Islands afford unique opportunities for such studies given their robust fossil and archaeological records. Herein, we examine the only non-volant terrestrial mammal endemic to the Bahamian Archipelago, the hutia Geocapromys ingrahami. This capromyine rodent once inhabited many islands but is now restricted to several small cays. Radiocarbon dated fossils indicate that hutias were present on the Great Bahama Bank islands before humans arrived at AD ~800-1000; all dates from other islands post-date human arrival. Using ancient DNA from a subset of these fossils, along with modern representatives of Bahamian hutia and related taxa, we develop a fossil-calibrated phylogeny. We found little genetic divergence among individuals from within either the northern or southern Bahamas but discovered a relatively deep North-South divergence (~750 ka). This result, combined with radiocarbon dating and archaeological evidence, reveals a pre-human biogeographic divergence, and an unexpected human role in shaping Bahamian hutia diversity and biogeography across islands.

RevDate: 2020-01-29

Barbato M, Hailer F, Upadhyay M, et al (2020)

Adaptive introgression from indicine cattle into white cattle breeds from Central Italy.

Scientific reports, 10(1):1279 pii:10.1038/s41598-020-57880-4.

Cattle domestication occurred at least twice independently and gave rise to the modern taurine and indicine cattle breeds. European cattle diversity is generally dominated by taurine cattle, although elevated levels of indicine ancestry have been recorded in several breeds from southern Europe. Here we use genome-wide high-density SNP genotyping data to investigate the taurine and indicine ancestry in southern European cattle, based on a dataset comprising 508 individuals from 23 cattle breeds of taurine, indicine and mixed ancestry, including three breeds from Central Italy known to exhibit the highest levels of indicine introgression among southern European breeds. Based on local genomic ancestry analyses, we reconstruct taurine and indicine ancestry genome-wide and along chromosomes. We scrutinise local genomic introgression signals and identify genomic regions that have introgressed from indicine into taurine cattle under positive selection, harbouring genes with functions related to body size and feed efficiency. These findings suggest that indicine-derived traits helped enhance Central Italian cattle through adaptive introgression. The identified genes could provide genomic targets for selection for improved cattle performance. Our findings elucidate the key role of adaptive introgression in shaping the phenotypic features of modern cattle, aided by cultural and livestock exchange among historic human societies.

RevDate: 2020-01-28

Gismondi A, Baldoni M, Gnes M, et al (2020)

A multidisciplinary approach for investigating dietary and medicinal habits of the Medieval population of Santa Severa (7th-15th centuries, Rome, Italy).

PloS one, 15(1):e0227433 pii:PONE-D-19-21430.

A multidisciplinary approach, combining stable isotope analysis from bone proteins and investigations on dental calculus using DNA analysis, light microscopy, and gas chromatography coupled with mass spectrometry, was applied to reconstruct dietary and medicinal habits of the individuals recovered in the cemetery of the Castle of Santa Severa (7th-15th centuries CE; Rome, Italy). Stable isotope analysis was performed on 120 humans, 41 faunal specimens and 8 charred seeds. Dental calculus analyses were carried out on 94 samples. Overall, isotope data indicated an omnivorous diet based on C3-terrestrial protein, although some individuals possessed carbon values indicative of C4 plant consumption. In terms of animal protein, the diet was probably based on cattle, sheep, pig and chicken products, as witnessed by the archaeozoological findings. Evidence from calculus suggested the consumption of C3 cereals, Fabaceae, Fagaceae, milk and dairy products. Secondary metabolites of herbs and wine were also detected. The detection of marine fish ancient DNA, as well as of ω3 fatty acids in calculus, hypothesized the consumption of marine foodstuffs for this coastal population, despite the lack of a clear marine isotopic signal and the presence of polyunsaturated fatty acids in plant tissues. Moreover, the knowledge of ethnopharmacological tradition and the application of medicinal plants (e.g. Punica granatum L., Ephedra sp. L.) were also identified. The detection of artemisinin, known to have antimalarial properties, led to hypothesize the presence of malaria in the area. Altogether, the combined application of microscopy and biomolecular techniques provided an innovative reconstruction of Medieval lifeways in Central Italy.

RevDate: 2020-01-27

Segawa T, T Yonezawa (2020)

Evaluation of reported sediment samples from 20 Ma using a molecular phylogenetic approach: Comment on Liu et al. (2017).

Environmental microbiology [Epub ahead of print].

Liu et al. (2017) reported the cultivation and DNA sequencing of 69 fungal isolates (Ascomycota and Basidiomycota) from ancient subseafloor sediments, suggesting that they represent living fungal populations that have persisted for over 20 million years. Because these findings could bring about a paradigm shift in our understanding of the spatial breadth of the deep subsurface biosphere as well as the longevity of ancient DNA, it is extremely important to verify that their samples represent pure ancient fungi from 20 million years ago without contamination by modern species. For this purpose, we estimated the divergence times among Dikarya fungi (Ascomycete + Basidiomycete) assuming that the fungal isolates were actually sampled from 20 Ma (mega-annum) sediments and evaluated the validity of the sample ages. Using this approach, we estimate that the age of the last common ancestor of Dikarya fungi greatly exceeds the age of the Earth. Our finding emphasizes the importance of using reliable approaches to confirm the dating of ancient samples. This article is protected by copyright. All rights reserved.

RevDate: 2020-01-23

Taylor WTT, Clark J, Bayarsaikhan J, et al (2020)

Early Pastoral Economies and Herding Transitions in Eastern Eurasia.

Scientific reports, 10(1):1001 pii:10.1038/s41598-020-57735-y.

While classic models for the emergence of pastoral groups in Inner Asia describe mounted, horse-borne herders sweeping across the Eurasian Steppes during the Early or Middle Bronze Age (ca. 3000-1500 BCE), the actual economic basis of many early pastoral societies in the region is poorly characterized. In this paper, we use collagen mass fingerprinting and ancient DNA analysis of some of the first stratified and directly dated archaeofaunal assemblages from Mongolia's early pastoral cultures to undertake species identifications of this rare and highly fragmented material. Our results provide evidence for livestock-based, herding subsistence in Mongolia during the late 3rd and early 2nd millennia BCE. We observe no evidence for dietary exploitation of horses prior to the late Bronze Age, ca. 1200 BCE - at which point horses come to dominate ritual assemblages, play a key role in pastoral diets, and greatly influence pastoral mobility. In combination with the broader archaeofaunal record of Inner Asia, our analysis supports models for widespread changes in herding ecology linked to the innovation of horseback riding in Central Asia in the final 2nd millennium BCE. Such a framework can explain key broad-scale patterns in the movement of people, ideas, and material culture in Eurasian prehistory.

RevDate: 2020-01-22

Nelson EA, Buikstra JE, Herbig A, et al (2020)

Advances in the molecular detection of tuberculosis in pre-contact Andean South America.

International journal of paleopathology pii:S1879-9817(19)30153-6 [Epub ahead of print].

Andean paleopathological research has significantly enhanced knowledge about the geographical distribution and evolution of tuberculosis (TB) in pre-Columbian South America. In this paper, we review the history and progress of research on ancient tuberculosis (TB) in the Andean region, focusing on the strengths and limitations of current approaches for the molecular detection of ancient pathogens, with special attention to TB. As a case study, we describe a molecular screening approach for the detection of ancient Mycobacterium tuberculosis in individuals from Late Intermediate Period (1000-1400 CE) contexts at the site of Huari, Peru. We evaluate 34 commingled human vertebrae and combine morphological assessments of pathology with high throughput sequencing and a non-selective approach to ancient pathogen DNA screening. Our method enabled the simultaneous detection of ancient M. tuberculosis DNA and an evaluation of the environmental microbial composition of each sample. Our results show that despite the dominance of environmental DNA, molecular signatures of M. tuberculosis were identified in eight vertebrae, six of which had no observable skeletal pathology classically associated tuberculosis infection. This screening approach will assist in the identification of candidate samples for downstream genomic analyses. The method permits higher resolution disease identification in cases where pathology may be absent, or where the archaeological context may necessitate a broad differential diagnosis based on morphology alone.

RevDate: 2020-01-21

Napier JD, de Lafontaine G, ML Chipman (2020)

The Evolution of Paleoecology.

Trends in ecology & evolution pii:S0169-5347(19)30351-9 [Epub ahead of print].

While the interplay between migration and adaptation dictates species response to climate change, technological limitations have obfuscated explicit tests on past adaptive responses. However, a surge in technology-driven advances in paleoecological methods coincides with breakthroughs in processing ancient DNA, providing the first opportunity to assess adaptation to past climate shifts.

RevDate: 2020-01-20

Schmidt N, Schücker K, Krause I, et al (2020)

Genome-wide SNP typing of ancient DNA: Determination of hair and eye color of Bronze Age humans from their skeletal remains.

American journal of physical anthropology [Epub ahead of print].

OBJECTIVE: A genome-wide high-throughput single nucleotide polymorphism (SNP) typing method was tested with respect of the applicability to ancient and degraded DNA. The results were compared to mini-sequencing data achieved through single base extension (SBE) typing. The SNPs chosen for the study allow to determine the hair colors and eye colors of humans.

MATERIAL AND METHODS: The DNA samples were extracted from the skeletal remains of 59 human individuals dating back to the Late Bronze Age. The 3,000 years old bones had been discovered in the Lichtenstein Cave in Lower Saxony, Germany. The simultaneous typing of 24 SNPs for each of the ancient DNA samples was carried out using the 192.24 Dynamic Array™ by Fluidigm®.

RESULTS: Thirty-eight of the ancient samples (=64%) revealed full and reproducible SNP genotypes allowing hair and eye color phenotyping. In 10 samples (=17%) at least half of the SNPs were unambiguously determined, in 11 samples (=19%) the SNP typing failed. For 23 of the 59 individuals, a comparison of the SNP typing results with genotypes from an earlier performed SBE typing approach was possible. The comparison confirmed the full concordance of the results for 90% of the SNP typings. In the remaining 10% allelic dropouts were identified.

DISCUSSION: The high genotyping success rate could be achieved by introducing modifications to the preamplification protocol mainly by increasing the DNA input and the amplification cycle number. The occurrence of allelic dropouts indicates that a further increase of DNA input to the preamplification step is desirable.

RevDate: 2020-01-16

Selway CA, Eisenhofer R, LS Weyrich (2020)

Microbiome applications for pathology: challenges of low microbial biomass samples during diagnostic testing.

The journal of pathology. Clinical research [Epub ahead of print].

The human microbiome can play key roles in disease, and diagnostic testing will soon have the ability to examine these roles in the context of clinical applications. Currently, most diagnostic testing in pathology applications focuses on a small number of disease-causing microbes and dismisses the whole microbial community that causes or is modulated by disease. Microbiome modifications have already provided clinically relevant insights in gut and oral diseases, such as irritable bowel disease, but there are currently limitations when clinically examining microbiomes outside of these body sites. This is critical, as the majority of microbial samples used in pathology originate from body sites that contain low concentrations of microbial DNA, including skin, tissue, blood, and urine. These samples, also known as low microbial biomass samples, are difficult to examine without careful consideration and precautions to mitigate contamination and biases. Here, we present the limitations when analysing low microbial biomass samples using current protocols and techniques and highlight the advantages that microbiome testing can offer diagnostics in the future, if the proper precautions are implemented. Specifically, we discuss the sources of contamination and biases that may result in false assessments for these sample types. Finally, we provide recommendations to mitigate contamination and biases from low microbial biomass samples during diagnostic testing, which will be especially important to effectively diagnose and treat patients using microbiome analyses.

RevDate: 2020-01-16

Öhrström L, Tekin A, Biedermann P, et al (2020)

Experimental mummification - In the tracks of the ancient Egyptians.

Clinical anatomy (New York, N.Y.) [Epub ahead of print].

Understanding natural and artificial postmortem alterations in different tissues of the human body is essential for bioarchaeology, paleogenetics, physical anthropology, forensic medicine, and many related disciplines. With this study, we tried to gain a better understanding of tissue alterations associated with the artificial mummification techniques of ancient Egypt, in particular for mummified visceral organs. We used several entire porcine organs and organ sections (liver, lung, stomach, ileum, and colon), which provided a close approximation to human organs. First, we dehydrated the specimens in artificial natron, before applying natural ointments, according to the ancient literary sources and recent publications. We periodically monitored the temperature, pH value, and weight of the specimens, in addition to radiodensity and volumetric measurements by clinical computed tomography and sampling for histological, bacteriological, and molecular analyses. After seven weeks, mummification was seen completed in all organs. We observed a considerable loss of weight and volume. We observed similar courses in the decay of tissue architecture but varying levels of DNA degradation. Bacteriologically we did not detect any of the initially identified taxa in the samples by the end of the mummification process, nor any fungi. This feasibility study established an experimental protocol for future experiments modeling ancient Egyptian mummification of visceral organs using human specimens. Understanding desiccation and mummification processes in non-pathological tissues of specific visceral organs may help to identify and interpret disease-specific alterations in mummified tissues in ancient Egyptian canopic jars and organ packages contained in whole mummies. This article is protected by copyright. All rights reserved.

RevDate: 2020-01-16

Gabbianelli F, Alhaique F, Romagnoli G, et al (2020)

Was the Cinta Senese Pig Already a Luxury Food in the Late Middle Ages? Ancient DNA and Archaeozoological Evidence from Central Italy.

Genes, 11(1): pii:genes11010085.

The Cinta senese is a pig breed, highly esteemed for its meat and derived products, characterized by a black coat with a typical white "belt" and documented by scant iconography, since the 13th-14th century in Italy. A piece of pottery showing a Cinta pig was found in the Graffignano castle (Northern Latium, Italy) dated 15th-16th centuries, spurring us to investigate the diet of the inhabitants. Ancient DNA analysis was carried out on 21 pig specimens on three nuclear SNPs: (1) g.43597545C>T, on the KIT gene, informative for the identification of the Cinta senese breed; (2) rs81460129, on an intergenic region in chr. 16, which discriminates between domestic pigs and wild boars, and; (3) a SNP on the ZFY/ZFX homologous genes, to determine the sex of the individuals. Our results indicate that the Cinta senese was present in Northern Latium in Late Medieval time, although it was not the only breed, and that pigs, including Cinta, interbred with wild boars, suggesting free-range breeding for all types of pigs. Moreover, the unexpected high proportion of young females may be considered as evidence for the wealth of the family inhabiting the castle.

RevDate: 2020-01-15

Płoszaj T, Jędrychowska-Dańska K, Zamerska A, et al (2020)

Analysis of maternal lineage structure of individuals from chamber graves placed in medieval cemetery in Kałdus, Central Poland.

Homo : internationale Zeitschrift fur die vergleichende Forschung am Menschen [Epub ahead of print].

The beginning of the early Middle Ages period in Poland (10th-14th century) has been widely debated in the context of an active demographic inflow from other countries and its contribution to the creation of the new country. Finding chamber graves which are considered typical for the Scandinavian ethnic group in a few cemeteries in Poland has become the basis for the anthropological inference on the potential participation of North European people in forming the social elite of medieval Poland. However, the question of whether this fact was the result of presence of people from other countries lacks an unambiguous answer. We attempted to isolate ancient DNA from the medieval necropolis in Kałdus where several chamber graves have been found and analysed the genetic diversity of maternal lineage of this population. We analysed the HVR I fragment and coding regions to assess the mitochondrial DNA haplogroup. We have identified a few relatively rare haplogroups (A2, T2b4a, HV, K1a11, J2b1a, and X2) which were previously found in early medieval sites in Norway and Denmark. Obtained results might suggest genetic relation between the people of Kałdus and past northern Europe populations. Present and further research can undoubtedly shed new light on the aspect of the formation of the early medieval Polish population.

RevDate: 2020-01-11

Kashuba N, Kırdök E, Damlien H, et al (2019)

Ancient DNA from mastics solidifies connection between material culture and genetics of mesolithic hunter-gatherers in Scandinavia.

Communications biology, 2(1):185 pii:10.1038/s42003-019-0399-1.

Human demography research in grounded on the information derived from ancient DNA and archaeology. For example, the study on the early postglacial dual-route colonisation of the Scandinavian Peninsula is largely based on associating genomic data with the early dispersal of lithic technology from the East European Plain. However, a clear connection between material culture and genetics has been lacking. Here, we demonstrate that direct connection by analysing human DNA from chewed birch bark pitch mastics. These samples were discovered at Huseby Klev in western Sweden, a Mesolithic site with eastern lithic technology. We generated genome-wide data for three individuals, and show their affinity to the Scandinavian hunter-gatherers. Our samples date to 9880-9540 calBP, expanding the temporal range and distribution of the early Scandinavian genetic group. We propose that DNA from ancient mastics can be used to study environment and ecology of prehistoric populations.

RevDate: 2020-01-08

Zhang M, Sun G, Ren L, et al (2020)

Ancient DNA evidence from China reveals the expansion of Pacific dogs.

Molecular biology and evolution pii:5698279 [Epub ahead of print].

The ancestral homeland of Australian dingoes and Pacific dogs is proposed to be in South China. However, the location and timing of their dispersal and relationship to dog domestication is unclear. Here, we sequenced 7,000 to 2,000-year-old complete mitochondrial DNA (mtDNA) genomes of 27 ancient canids (one gray wolf and 26 domestic dogs) from the Yellow River and Yangtze River basins (YYRB). These are the first complete ancient mtDNA of Chinese dogs from the cradle of early Chinese civilization. We found that most ancient dogs (18/26) belong to the haplogroup A1b lineage that is found in high frequency in present-day Australian dingoes and pre-colonial Pacific Island dogs, but low frequency in present-day China. Particularly, a 7,000-year-old dog from the Tianluoshan site in Zhejiang province possesses a haplotype basal to the entire haplogroup A1b lineage. We propose that A1b lineage dogs were once widely distributed in the YYRB area. Following their dispersal to South China, and then into Southeast Asia, New Guinea and remote Oceania, they were largely replaced by dogs belonging to other lineages in the last 2,000 years in present-day China, especially North China.

RevDate: 2020-01-15

Barlow A, Hartmann S, Gonzalez J, et al (2020)

Consensify: A Method for Generating Pseudohaploid Genome Sequences from Palaeogenomic Datasets with Reduced Error Rates.

Genes, 11(1): pii:genes11010050.

A standard practise in palaeogenome analysis is the conversion of mapped short read data into pseudohaploid sequences, frequently by selecting a single high-quality nucleotide at random from the stack of mapped reads. This controls for biases due to differential sequencing coverage, but it does not control for differential rates and types of sequencing error, which are frequently large and variable in datasets obtained from ancient samples. These errors have the potential to distort phylogenetic and population clustering analyses, and to mislead tests of admixture using D statistics. We introduce Consensify, a method for generating pseudohaploid sequences, which controls for biases resulting from differential sequencing coverage while greatly reducing error rates. The error correction is derived directly from the data itself, without the requirement for additional genomic resources or simplifying assumptions such as contemporaneous sampling. For phylogenetic and population clustering analysis, we find that Consensify is less affected by artefacts than methods based on single read sampling. For D statistics, Consensify is more resistant to false positives and appears to be less affected by biases resulting from different laboratory protocols than other frequently used methods. Although Consensify is developed with palaeogenomic data in mind, it is applicable for any low to medium coverage short read datasets. We predict that Consensify will be a useful tool for future studies of palaeogenomes.

RevDate: 2020-01-08

Silva-Pereira TT, Ikuta CY, Zimpel CK, et al (2019)

Genome sequencing of Mycobacterium pinnipedii strains: genetic characterization and evidence of superinfection in a South American sea lion (Otaria flavescens).

BMC genomics, 20(1):1030.

BACKGROUND: Mycobacterium pinnipedii, a member of the Mycobacterium tuberculosis Complex (MTBC), is capable of infecting several host species, including humans. Recently, ancient DNA from this organism was recovered from pre-Columbian mummies of Peru, sparking debate over the origin and frequency of tuberculosis in the Americas prior to European colonization.

RESULTS: We present the first comparative genomic study of this bacterial species, starting from the genome sequencing of two M. pinnipedii isolates (MP1 and MP2) obtained from different organs of a stranded South American sea lion. Our results indicate that MP1 and MP2 differ by 113 SNPs (single nucleotide polymorphisms) and 46 indels, constituting the first report of a mixed-strain infection in a sea lion. SNP annotation analyses indicate that genes of the VapBC family, a toxin-antitoxin system, and genes related to cell wall remodeling are under evolutionary pressure for protein sequence change in these strains. OrthoMCL analysis with seven modern isolates of M. pinnipedii shows that these strains have highly similar proteomes. Gene variations were only marginally associated with hypothetical proteins and PE/PPE (proline-glutamate and proline-proline-glutamate, respectively) gene families. We also detected large deletions in ancient and modern M. pinnipedii strains, including a few occurring only in modern strains, indicating a process of genome reduction occurring over the past one thousand years. Our phylogenomic analyses suggest the existence of two modern clusters of M. pinnipedii associated with geographic location, and possibly host species, and one basal node associated with the ancient M. pinnipedii strains. Previously described MiD3 and MiD4 deletions may have occurred independently, twice, over the evolutionary course of the MTBC.

CONCLUSION: The presence of superinfection (i.e. mixed-strain infection) in this sea lion suggests that M. pinnipedii is highly endemic in this population. Mycobacterium pinnipedii proteomes of the studied isolates showed a high degree of conservation, despite being under genomic decay when compared to M. tuberculosis. This finding indicates that further genomes need to be sequenced and analyzed to increase the chances of finding variably present genes among strains or that M. pinnipedii genome remodeling occurred prior to bacterial speciation.

RevDate: 2020-01-08

Troll CJ, Kapp J, Rao V, et al (2019)

A ligation-based single-stranded library preparation method to analyze cell-free DNA and synthetic oligos.

BMC genomics, 20(1):1023.

BACKGROUND: Cell-free DNA (cfDNA), present in circulating blood plasma, contains information about prenatal health, organ transplant reception, and cancer presence and progression. Originally developed for the genomic analysis of highly degraded ancient DNA, single-stranded DNA (ssDNA) library preparation methods are gaining popularity in the field of cfDNA analysis due to their efficiency and ability to convert short, fragmented DNA into sequencing libraries without altering DNA ends. However, current ssDNA methods are costly and time-consuming.

RESULTS: Here we present an efficient ligation-based single-stranded library preparation method that is engineered to produce complex libraries in under 2.5 h from as little as 1 nanogram of input DNA without alteration to the native ends of template molecules. Our method, called Single Reaction Single-stranded LibrarY or SRSLY, ligates uniquely designed Next-Generation Sequencing (NGS) adapters in a one-step combined phosphorylation/ligation reaction that foregoes end-polishing. Using synthetic DNA oligos and cfDNA, we demonstrate the efficiency and utility of this approach and compare with existing double-stranded and single-stranded approaches for library generation. Finally, we demonstrate that cfDNA NGS data generated from SRSLY can be used to analyze DNA fragmentation patterns to deduce nucleosome positioning and transcription factor binding.

CONCLUSIONS: SRSLY is a versatile tool for converting short and fragmented DNA molecules, like cfDNA fragments, into sequencing libraries while retaining native lengths and ends.

RevDate: 2020-01-08

Batyrev D, Lapid E, Carmel L, et al (2019)

Predicted Archaic 3D Genome Organization Reveals Genes Related to Head and Spinal Cord Separating Modern from Archaic Humans.

Cells, 9(1): pii:cells9010048.

High coverage sequences of archaic humans enabled the reconstruction of their DNA methylation patterns. This allowed comparing gene regulation between human groups, and linking such regulatory changes to phenotypic differences. In a previous work, a detailed comparison of DNA methylation in modern humans, archaic humans, and chimpanzees revealed 873 modern human-derived differentially methylated regions (DMRs). To understand the regulatory implications of these DMRs, we defined differentially methylated genes (DMGs) as genes that harbor DMRs in their promoter or gene body. While most of the modern human-derived DMRs could be linked to DMGs, many others remained unassigned. Here, we used information on 3D genome organization to link ~70 out of the remaining 288 unassigned DMRs to genes. Combined with the previously identified DMGs, we reinforce the enrichment of these genes with vocal and facial anatomy, and additionally find significant enrichment with the spinal column, chin, hair, and scalp. These results reveal the importance of 3D genomic organization in understanding gene regulation by DNA methylation.

RevDate: 2020-01-08

Clarke CL, Edwards ME, Gielly L, et al (2019)

Persistence of arctic-alpine flora during 24,000 years of environmental change in the Polar Urals.

Scientific reports, 9(1):19613.

Plants adapted to extreme conditions can be at high risk from climate change; arctic-alpine plants, in particular, could "run out of space" as they are out-competed by expansion of woody vegetation. Mountain regions could potentially provide safe sites for arctic-alpine plants in a warmer climate, but empirical evidence is fragmentary. Here we present a 24,000-year record of species persistence based on sedimentary ancient DNA (sedaDNA) from Lake Bolshoye Shchuchye (Polar Urals). We provide robust evidence of long-term persistence of arctic-alpine plants through large-magnitude climate changes but document a decline in their diversity during a past expansion of woody vegetation. Nevertheless, most of the plants that were present during the last glacial interval, including all of the arctic-alpines, are still found in the region today. This underlines the conservation significance of mountain landscapes via their provision of a range of habitats that confer resilience to climate change, particularly for arctic-alpine taxa.

RevDate: 2020-01-09

Lavretsky P, McInerney NR, Mohl JE, et al (2019)

Assessing changes in genomic divergence following a century of human-mediated secondary contact among wild and captive-bred ducks.

Molecular ecology [Epub ahead of print].

Along with manipulating habitat, the direct release of domesticated individuals into the wild is a practice used worldwide to augment wildlife populations. We test between possible outcomes of human-mediated secondary contact using genomic techniques at both historical and contemporary timescales for two iconic duck species. First, we sequence several thousand ddRAD-seq loci for contemporary mallards (Anas platyrhynchos) throughout North America and two domestic mallard types (i.e., known game-farm mallards and feral Khaki Campbell's). We show that North American mallards may well be becoming a hybrid swarm due to interbreeding with domesticated game-farm mallards released for hunting. Next, to attain a historical perspective, we applied a bait-capture array targeting thousands of loci in century-old (1842-1915) and contemporary (2009-2010) mallard and American black duck (Anas rubripes) specimens. We conclude that American black ducks and mallards have always been closely related, with a divergence time of ~600,000 years before present, and likely evolved through prolonged isolation followed by limited bouts of gene flow (i.e., secondary contact). They continue to maintain genetic separation, a finding that overturns decades of prior research and speculation suggesting the genetic extinction of the American black duck due to contemporary interbreeding with mallards. Thus, despite having high rates of hybridization, actual gene flow is limited between mallards and American black ducks. Conversely, our historical and contemporary data confirm that the intensive stocking of game-farm mallards during the last ~100 years has fundamentally changed the genetic integrity of North America's wild mallard population, especially in the east. It thus becomes of great interest to ask whether the iconic North American mallard is declining in the wild due to introgression of maladaptive traits from domesticated forms. Moreover, we hypothesize that differential gene flow from domestic game-farm mallards into the wild mallard population may explain the overall temporal increase in differentiation between wild black ducks and mallards, as well as the uncoupling of genetic diversity and effective population size estimates across time in our results. Finally, our findings highlight how genomic methods can recover complex population histories by capturing DNA preserved in traditional museum specimens.

RevDate: 2020-01-22

Vershinina AO, Kapp JD, Baryshnikov GF, et al (2019)

The case of an arctic wild ass highlights the utility of ancient DNA for validating problematic identifications in museum collections.

Molecular ecology resources [Epub ahead of print].

Museum collections are essential for reconstructing and understanding past biodiversity. Many museum specimens are, however, challenging to identify. Museum samples may be incomplete, have an unusual morphology, or represent juvenile individuals, all of which complicate accurate identification. In some cases, inaccurate identification can lead to false biogeographic reconstructions with cascading impacts on paleontological and paleoecological research. Here, we analyzed an unusual Equid mandible found in the Far North of the Taymyr peninsula that was identified morphologically as Equus hemionus, an ancestor of present-day Asiatic wild asses. If correct, this identification represents the only finding of a putative Late Pleistocene hemione in the Arctic region, and is therefore critical to understanding wild ass evolution and paleoecology. To confirm the accuracy of this specimen's taxonomic assignment, we used ancient DNA and mitochondrial hybridization capture to identify and place this specimen in the larger equid phylogeny. We find that the specimen is actually a member of E. caballus, the ancestor of domestic horses. Our study demonstrates the utility of ancient DNA to validate morphological identification, in particular of incomplete, otherwise problematic, or taxonomically unusual museum specimens.

RevDate: 2019-12-23

De Simone G, Pasquadibisceglie A, Proietto R, et al (2019)

Contaminations in (meta)genome data: An open issue for the scientific community.

IUBMB life [Epub ahead of print].

In recent years, the high throughput and the low cost of next-generation sequencing (NGS) technologies have led to an increase of the amount of (meta)genomic data, revolutionizing genomic research studies. However, the quality of sequencing data could be affected by experimental errors derived from defective methods and protocols. This represents a serious problem for the scientific community with a negative impact on the correctness of studies that involve genomic sequence analysis. As a countermeasure, several alignment and taxonomic classification tools have been developed to uncover and correct errors. In this critical review some of these integrated software tools and pipelines used to detect contaminations in reference genome databases and sequenced samples are reported. In particular, case studies of bacterial contaminations, contaminations of human origin, mitochondrial contaminations of ancient DNA, and cross contaminations are examined.

RevDate: 2020-01-08

Henao E, Rzymski P, MN Waters (2019)

A Review on the Study of Cyanotoxins in Paleolimnological Research: Current Knowledge and Future Needs.

Toxins, 12(1): pii:toxins12010006.

Cyanobacterial metabolites are increasingly studied, in regards to their biosynthesis, ecological role, toxicity, and potential biomedical applications. However, the history of cyanotoxins prior to the last few decades is virtually unknown. Only a few paleolimnological studies have been undertaken to date, and these have focused exclusively on microcystins and cylindrospermopsins, both successfully identified in lake sediments up to 200 and 4700 years old, respectively. In this paper, we review direct extraction, quantification, and application of cyanotoxins in sediment cores, and put forward future research prospects in this field. Cyanobacterial toxin research is also compared to other paleo-cyanobacteria tools, such as sedimentary pigments, akinetes, and ancient DNA isolation, to identify the role of each tool in reproducing the history of cyanobacteria. Such investigations may also be beneficial for further elucidation of the biological role of cyanotoxins, particularly if coupled with analyses of other abiotic and biotic sedimentary features. In addition, we identify current limitations as well as future directions for applications in the field of paleolimnological studies on cyanotoxins.

RevDate: 2020-01-08

Jensen TZT, Niemann J, Iversen KH, et al (2019)

A 5700 year-old human genome and oral microbiome from chewed birch pitch.

Nature communications, 10(1):5520.

The rise of ancient genomics has revolutionised our understanding of human prehistory but this work depends on the availability of suitable samples. Here we present a complete ancient human genome and oral microbiome sequenced from a 5700 year-old piece of chewed birch pitch from Denmark. We sequence the human genome to an average depth of 2.3× and find that the individual who chewed the pitch was female and that she was genetically more closely related to western hunter-gatherers from mainland Europe than hunter-gatherers from central Scandinavia. We also find that she likely had dark skin, dark brown hair and blue eyes. In addition, we identify DNA fragments from several bacterial and viral taxa, including Epstein-Barr virus, as well as animal and plant DNA, which may have derived from a recent meal. The results highlight the potential of chewed birch pitch as a source of ancient DNA.

RevDate: 2020-01-08

Hübler R, Key FM, Warinner C, et al (2019)

HOPS: automated detection and authentication of pathogen DNA in archaeological remains.

Genome biology, 20(1):280.

High-throughput DNA sequencing enables large-scale metagenomic analyses of complex biological systems. Such analyses are not restricted to present-day samples and can also be applied to molecular data from archaeological remains. Investigations of ancient microbes can provide valuable information on past bacterial commensals and pathogens, but their molecular detection remains a challenge. Here, we present HOPS (Heuristic Operations for Pathogen Screening), an automated bacterial screening pipeline for ancient DNA sequences that provides detailed information on species identification and authenticity. HOPS is a versatile tool for high-throughput screening of DNA from archaeological material to identify candidates for genome-level analyses.

RevDate: 2019-12-16

O'Neill MB, Laval G, Teixeira JC, et al (2019)

Genetic susceptibility to severe childhood asthma and rhinovirus-C maintained by balancing selection in humans for 150,000 years.

Human molecular genetics pii:5678746 [Epub ahead of print].

Selective pressures imposed by pathogens have varied among human populations throughout their evolution, leading to marked inter-population differences at some genes mediating susceptibility to infectious and immune-related diseases. Here, we investigated the evolutionary history of a common polymorphism resulting in a T529 versus C529 change in the Cadherin-Related Family Member 3 (CDHR3) receptor which underlies variable susceptibility to rhinovirus-C infection and is associated with severe childhood asthma. The protective variant is the derived allele and is found at high frequency worldwide (69-95%). We detected genome-wide significant signatures of natural selection consistent with a rapid increase of the haplotypes carrying the allele, suggesting non-neutral processes have acted on this locus across all human populations. However, the allele has not fixed in any population despite multiple lines of evidence suggesting the mutation predates human migrations out of Africa. Using an approximate Bayesian computation method, we estimate the age of the mutation while explicitly accounting for past demography and positive or frequency-dependent balancing selection. Our analyses indicate a single emergence of the mutation in anatomically modern humans ~150,000 years ago and indicate that balancing selection has maintained the beneficial allele at high equilibrium frequencies worldwide. Apart from the well-known cases of the MHC and ABO genes, this study provides the first evidence that negative frequency-dependent selection plausibly acted on a human disease susceptibility locus, a form of balancing selection compatible with typical transmission dynamics of communicable respiratory viruses that might exploit CDHR3.

RevDate: 2020-01-03

Loog L, Thalmann O, Sinding MS, et al (2019)

Ancient DNA suggests modern wolves trace their origin to a Late Pleistocene expansion from Beringia.

Molecular ecology [Epub ahead of print].

Grey wolves (Canis lupus) are one of the few large terrestrial carnivores that have maintained a wide geographical distribution across the Northern Hemisphere throughout the Pleistocene and Holocene. Recent genetic studies have suggested that, despite this continuous presence, major demographic changes occurred in wolf populations between the Late Pleistocene and early Holocene, and that extant wolves trace their ancestry to a single Late Pleistocene population. Both the geographical origin of this ancestral population and how it became widespread remain unknown. Here, we used a spatially and temporally explicit modelling framework to analyse a data set of 90 modern and 45 ancient mitochondrial wolf genomes from across the Northern Hemisphere, spanning the last 50,000 years. Our results suggest that contemporary wolf populations trace their ancestry to an expansion from Beringia at the end of the Last Glacial Maximum, and that this process was most likely driven by Late Pleistocene ecological fluctuations that occurred across the Northern Hemisphere. This study provides direct ancient genetic evidence that long-range migration has played an important role in the population history of a large carnivore, and provides insight into how wolves survived the wave of megafaunal extinctions at the end of the last glaciation. Moreover, because Late Pleistocene grey wolves were the likely source from which all modern dogs trace their origins, the demographic history described in this study has fundamental implications for understanding the geographical origin of the dog.

RevDate: 2019-12-27

Zanella M, Vitriolo A, Andirko A, et al (2019)

Dosage analysis of the 7q11.23 Williams region identifies BAZ1B as a major human gene patterning the modern human face and underlying self-domestication.

Science advances, 5(12):eaaw7908.

We undertook a functional dissection of chromatin remodeler BAZ1B in neural crest (NC) stem cells (NCSCs) from a uniquely informative cohort of typical and atypical patients harboring 7q11.23 copy number variants. Our results reveal a key contribution of BAZ1B to NCSC in vitro induction and migration, coupled with a crucial involvement in NC-specific transcriptional circuits and distal regulation. By intersecting our experimental data with new paleogenetic analyses comparing modern and archaic humans, we found a modern-specific enrichment for regulatory changes both in BAZ1B and its experimentally defined downstream targets, thereby providing the first empirical validation of the human self-domestication hypothesis and positioning BAZ1B as a master regulator of the modern human face. In so doing, we provide experimental evidence that the craniofacial and cognitive/behavioral phenotypes caused by alterations of the Williams-Beuren syndrome critical region can serve as a powerful entry point into the evolution of the modern human face and prosociality.

RevDate: 2019-12-18

Pálsdóttir AH, Bläuer A, Rannamäe E, et al (2019)

Not a limitless resource: ethics and guidelines for destructive sampling of archaeofaunal remains.

Royal Society open science, 6(10):191059.

With the advent of ancient DNA, as well as other methods such as isotope analysis, destructive sampling of archaeofaunal remains has increased much faster than the effort to collect and curate them. While there has been considerable discussion regarding the ethics of destructive sampling and analysis of human remains, this dialogue has not extended to archaeofaunal material. Here we address this gap and discuss the ethical challenges surrounding destructive sampling of materials from archaeofaunal collections. We suggest ways of mitigating the negative aspects of destructive sampling and present step-by-step guidelines aimed at relevant stakeholders, including scientists, holding institutions and scientific journals. Our suggestions are in most cases easily implemented without significant increases in project costs, but with clear long-term benefits in the preservation and use of zooarchaeological material.

RevDate: 2019-12-20

Orlando L (2020)

Ancient Genomes Reveal Unexpected Horse Domestication and Management Dynamics.

BioEssays : news and reviews in molecular, cellular and developmental biology, 42(1):e1900164.

The horse was essential to past human societies but became a recreational animal during the twentieth century as the world became increasingly mechanized. As the author reviews here, recent studies of ancient genomes have revisited the understanding of horse domestication, from the very early stages to the most modern developments. They have uncovered several extinct lineages roaming the far ends of Eurasia some 4000 years ago. They have shown that the domestic horse has been significantly reshaped during the last millennium and experienced a sharp decline in genetic diversity within the last two centuries. At a time when no truly wild horses exist any longer, this calls for enhanced conservation in all endangered populations. These include the Przewalski's horse native to Mongolia, and the many local breeds side-lined by the modern agenda, but yet representing the living heritage of over five millennia of horse breeding.

RevDate: 2019-12-18

Nazari V, Tarmann GM, KA Efetov (2019)

Phylogenetic position of the 'extinct' Fijian coconut moth, Levuana iridescens (Lepidoptera: Zygaenidae).

PloS one, 14(12):e0225590.

Levuana iridescens Bethune-Baker, 1906, a day-flying moth purported to be endemic to the Fijian Island of Viti Levu and a former pest of its coconut palm trees, was last observed in 1956 and has been officially declared extinct by IUCN since 1996. The controversial classical biological control method that resulted in the (presumed) demise of this moth has given this species an iconic status in biological control studies. We investigated the sister-group relationships and phylogenetic placement of this moth using NGS-obtained ancient DNA sequences from museum specimens of L. iridescens collected in the 1920s, combined with 31 morphological characters used in earlier studies and 2 new characters. Our findings show that Levuana is most closely related to the Australian genus Myrtartona. The significance of these findings is discussed.

RevDate: 2019-12-24

Mordechai L, Eisenberg M, Newfield TP, et al (2019)

The Justinianic Plague: An inconsequential pandemic?.

Proceedings of the National Academy of Sciences of the United States of America, 116(51):25546-25554.

Existing mortality estimates assert that the Justinianic Plague (circa 541 to 750 CE) caused tens of millions of deaths throughout the Mediterranean world and Europe, helping to end antiquity and start the Middle Ages. In this article, we argue that this paradigm does not fit the evidence. We examine a series of independent quantitative and qualitative datasets that are directly or indirectly linked to demographic and economic trends during this two-century period: Written sources, legislation, coinage, papyri, inscriptions, pollen, ancient DNA, and mortuary archaeology. Individually or together, they fail to support the maximalist paradigm: None has a clear independent link to plague outbreaks and none supports maximalist reconstructions of late antique plague. Instead of large-scale, disruptive mortality, when contextualized and examined together, the datasets suggest continuity across the plague period. Although demographic, economic, and political changes continued between the 6th and 8th centuries, the evidence does not support the now commonplace claim that the Justinianic Plague was a primary causal factor of them.

RevDate: 2020-01-08

McHugo GP, Dover MJ, DE MacHugh (2019)

Unlocking the origins and biology of domestic animals using ancient DNA and paleogenomics.

BMC biology, 17(1):98.

Animal domestication has fascinated biologists since Charles Darwin first drew the parallel between evolution via natural selection and human-mediated breeding of livestock and companion animals. In this review we show how studies of ancient DNA from domestic animals and their wild progenitors and congeners have shed new light on the genetic origins of domesticates, and on the process of domestication itself. High-resolution paleogenomic data sets now provide unprecedented opportunities to explore the development of animal agriculture across the world. In addition, functional population genomics studies of domestic and wild animals can deliver comparative information useful for understanding recent human evolution.

RevDate: 2019-12-02

Beltrame MO, Pruzzo C, Sanabria R, et al (2019)

FIRST REPORT OF PREHISPANIC FASCIOLA HEPATICA FROM SOUTH AMERICA REVEALED BY ANCIENT DNA.

Parasitology pii:S0031182019001719 [Epub ahead of print].

RevDate: 2020-01-16

Hagan RW, Hofman CA, Hübner A, et al (2020)

Comparison of extraction methods for recovering ancient microbial DNA from paleofeces.

American journal of physical anthropology, 171(2):275-284.

OBJECTIVES: Paleofeces are valuable to archeologists and evolutionary biologists for their potential to yield health, dietary, and host information. As a rich source of preserved biomolecules from host-associated microorganisms, they can also provide insights into the recent evolution and changing ecology of the gut microbiome. However, there is currently no standard method for DNA extraction from paleofeces, which combine the dual challenges of complex biological composition and degraded DNA. Due to the scarcity and relatively poor preservation of paleofeces when compared with other archeological remains, it is important to use efficient methods that maximize ancient DNA (aDNA) recovery while also minimizing downstream taxonomic biases.

METHODS: In this study, we use shotgun metagenomics to systematically compare the performance of five DNA extraction methods on a set of well-preserved human and dog paleofeces from Mexico (~1,300 BP).

RESULTS: Our results show that all tested DNA extraction methods yield a consistent microbial taxonomic profile, but that methods optimized for ancient samples recover significantly more DNA.

CONCLUSIONS: These results show promise for future studies that seek to explore the evolution of the human gut microbiome by comparing aDNA data with those generated in modern studies.

RevDate: 2020-01-15

Ameen C, Feuerborn TR, Brown SK, et al (2019)

Specialized sledge dogs accompanied Inuit dispersal across the North American Arctic.

Proceedings. Biological sciences, 286(1916):20191929.

Domestic dogs have been central to life in the North American Arctic for millennia. The ancestors of the Inuit were the first to introduce the widespread usage of dog sledge transportation technology to the Americas, but whether the Inuit adopted local Palaeo-Inuit dogs or introduced a new dog population to the region remains unknown. To test these hypotheses, we generated mitochondrial DNA and geometric morphometric data of skull and dental elements from a total of 922 North American Arctic dogs and wolves spanning over 4500 years. Our analyses revealed that dogs from Inuit sites dating from 2000 BP possess morphological and genetic signatures that distinguish them from earlier Palaeo-Inuit dogs, and identified a novel mitochondrial clade in eastern Siberia and Alaska. The genetic legacy of these Inuit dogs survives today in modern Arctic sledge dogs despite phenotypic differences between archaeological and modern Arctic dogs. Together, our data reveal that Inuit dogs derive from a secondary pre-contact migration of dogs distinct from Palaeo-Inuit dogs, and probably aided the Inuit expansion across the North American Arctic beginning around 1000 BP.

RevDate: 2020-01-08

Thomas JE, Carvalho GR, Haile J, et al (2019)

Demographic reconstruction from ancient DNA supports rapid extinction of the great auk.

eLife, 8:.

The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial genomes of 41 individuals from across the species' geographic range and reconstructed population structure and population dynamics throughout the Holocene. Taken together, our data do not provide any evidence that great auks were at risk of extinction prior to the onset of intensive human hunting in the early 16th century. In addition, our population viability analyses reveal that even if the great auk had not been under threat by environmental change, human hunting alone could have been sufficient to cause its extinction. Our results emphasise the vulnerability of even abundant and widespread species to intense and localised exploitation.

RevDate: 2020-01-21

Fenderson LE, Kovach AI, B Llamas (2020)

Spatiotemporal landscape genetics: Investigating ecology and evolution through space and time.

Molecular ecology, 29(2):218-246.

Genetic time-series data from historical samples greatly facilitate inference of past population dynamics and species evolution. Yet, although climate and landscape change are often touted as post-hoc explanations of biological change, our understanding of past climate and landscape change influences on evolutionary processes is severely hindered by the limited application of methods that directly relate environmental change to species dynamics through time. Increased integration of spatiotemporal environmental and genetic data will revolutionize the interpretation of environmental influences on past population processes and the quantification of recent anthropogenic impacts on species, and vastly improve prediction of species responses under future climate change scenarios, yielding widespread revelations across evolutionary biology, landscape ecology and conservation genetics. This review encourages greater use of spatiotemporal landscape genetic analyses that explicitly link landscape, climate and genetic data through time by providing an overview of analytical approaches for integrating historical genetic and environmental data in five key research areas: population genetic structure, demography, phylogeography, metapopulation connectivity and adaptation. We also include a tabular summary of key methodological information, suggest approaches for mitigating the particular difficulties in applying these techniques to ancient DNA and palaeoclimate data, and highlight areas for future methodological development.

RevDate: 2020-01-08

Ozga AT, Gilby I, Nockerts RS, et al (2019)

Oral microbiome diversity in chimpanzees from Gombe National Park.

Scientific reports, 9(1):17354 pii:10.1038/s41598-019-53802-1.

Historic calcified dental plaque (dental calculus) can provide a unique perspective into the health status of past human populations but currently no studies have focused on the oral microbial ecosystem of other primates, including our closest relatives, within the hominids. Here we use ancient DNA extraction methods, shotgun library preparation, and next generation Illumina sequencing to examine oral microbiota from 19 dental calculus samples recovered from wild chimpanzees (Pan troglodytes schweinfurthii) who died in Gombe National Park, Tanzania. The resulting sequences were trimmed for quality, analyzed using MALT, MEGAN, and alignment scripts, and integrated with previously published dental calculus microbiome data. We report significant differences in oral microbiome phyla between chimpanzees and anatomically modern humans (AMH), with chimpanzees possessing a greater abundance of Bacteroidetes and Fusobacteria, and AMH showing higher Firmicutes and Proteobacteria. Our results suggest that by using an enterotype clustering method, results cluster largely based on host species. These clusters are driven by Porphyromonas and Fusobacterium genera in chimpanzees and Haemophilus and Streptococcus in AMH. Additionally, we compare a nearly complete Porphyromonas gingivalis genome to previously published genomes recovered from human gingiva to gain perspective on evolutionary relationships across host species. Finally, using shotgun sequence data we assessed indicators of diet from DNA in calculus and suggest exercising caution when making assertions related to host lifestyle. These results showcase core differences between host species and stress the importance of continued sequencing of nonhuman primate microbiomes in order to fully understand the complexity of their oral ecologies.

RevDate: 2020-01-08

Maixner F, Thorell K, Granehäll L, et al (2019)

Helicobacter pylori in ancient human remains.

World journal of gastroenterology, 25(42):6289-6298.

The bacterium Helicobacter pylori (H. pylori) infects the stomachs of approximately 50% of all humans. With its universal occurrence, high infectivity and virulence properties it is considered as one of the most severe global burdens of modern humankind. It has accompanied humans for many thousands of years, and due to its high genetic variability and vertical transmission, its population genetics reflects the history of human migrations. However, especially complex demographic events such as the colonisation of Europe cannot be resolved with population genetic analysis of modern H. pylori strains alone. This is best exemplified with the reconstruction of the 5300-year-old H. pylori genome of the Iceman, a European Copper Age mummy. Our analysis provided precious insights into the ancestry and evolution of the pathogen and underlined the high complexity of ancient European population history. In this review we will provide an overview on the molecular analysis of H. pylori in mummified human remains that were done so far and we will outline methodological advancements in the field of ancient DNA research that support the reconstruction and authentication of ancient H. pylori genome sequences.

RevDate: 2020-01-24

Müller P, Sell C, Hadrys T, et al (2020)

Inter-laboratory study on standardized MPS libraries: evaluation of performance, concordance, and sensitivity using mixtures and degraded DNA.

International journal of legal medicine, 134(1):185-198.

We present results from an inter-laboratory massively parallel sequencing (MPS) study in the framework of the SeqForSTRs project to evaluate forensically relevant parameters, such as performance, concordance, and sensitivity, using a standardized sequencing library including reference material, mixtures, and ancient DNA samples. The standardized library was prepared using the ForenSeq DNA Signature Prep Kit (primer mix A). The library was shared between eight European laboratories located in Austria, France, Germany, The Netherlands, and Sweden to perform MPS on their particular MiSeq FGx sequencers. Despite variation in performance between sequencing runs, all laboratories obtained quality metrics that fell within the manufacturer's recommended ranges. Furthermore, differences in locus coverage did not inevitably adversely affect heterozygous balance. Inter-laboratory concordance showed 100% concordant genotypes for the included autosomal and Y-STRs, and still, X-STR concordance exceeded 83%. The exclusive reasons for X-STR discordances were drop-outs at DXS10103. Sensitivity experiments demonstrated that correct allele calling varied between sequencing instruments in particular for lower DNA amounts (≤ 125 pg). The analysis of compromised DNA samples showed the drop-out of one sample (FA10013B01A) while for the remaining three degraded DNA samples MPS was able to successfully type ≥ 87% of all aSTRs, ≥ 78% of all Y-STRs, ≥ 68% of all X-STRs, and ≥ 92% of all iSNPs demonstrating that MPS is a promising tool for human identity testing, which in return, has to undergo rigorous in-house validation before it can be implemented into forensic routine casework.

RevDate: 2020-01-08

Grugni V, Raveane A, Colombo G, et al (2019)

Y-chromosome and Surname Analyses for Reconstructing Past Population Structures: The Sardinian Population as a Test Case.

International journal of molecular sciences, 20(22): pii:ijms20225763.

Many anthropological, linguistic, genetic and genomic analyses have been carried out to evaluate the potential impact that evolutionary forces had in shaping the present-day Sardinian gene pool, the main outlier in the genetic landscape of Europe. However, due to the homogenizing effect of internal movements, which have intensified over the past fifty years, only partial information has been obtained about the main demographic events. To overcome this limitation, we analyzed the male-specific region of the Y chromosome in three population samples obtained by reallocating a large number of Sardinian subjects to the place of origin of their monophyletic surnames, which are paternally transmitted through generations in most of the populations, much like the Y chromosome. Three Y-chromosome founding lineages, G2-L91, I2-M26 and R1b-V88, were identified as strongly contributing to the definition of the outlying position of Sardinians in the European genetic context and marking a significant differentiation within the island. The present distribution of these lineages does not always mirror that detected in ancient DNAs. Our results show that the analysis of the Y-chromosome gene pool coupled with a sampling method based on the origin of the family name, is an efficient approach to unravelling past heterogeneity, often hidden by recent movements, in the gene pool of modern populations. Furthermore, the reconstruction and comparison of past genetic isolates represent a starting point to better assess the genetic information deriving from the increasing number of available ancient DNA samples.

RevDate: 2019-11-21

Chen P, Wu J, Luo L, et al (2019)

Population Genetic Analysis of Modern and Ancient DNA Variations Yields New Insights Into the Formation, Genetic Structure, and Phylogenetic Relationship of Northern Han Chinese.

Frontiers in genetics, 10:1045.

Modern East Asians derived from the admixture of aborigines and incoming farmers expanding from Yellow and Yangtze River Basins. Distinct genetic differentiation and subsequent admixture between Northeast Asians and Southeast Asians subsequently evidenced by the mitochondrial DNA, Y-chromosomal variations, and autosomal SNPs. Recently, population geneticists have paid more attention to the genetic polymorphisms and background of southern-Han Chinese and southern native populations. The genetic legacy of northern-Han remains uncharacterized. Thus, we performed this comprehensive population genetic analyses of modern and ancient genetic variations aiming to yield new insight into the formation of modern Han, and the genetic ancestry and phylogenetic relationship of the northern-Han Chinese population. We first genotyped 25 forensic associated markers in 3,089 northern-Han Chinese individuals using the new-generation of the Huaxia Platinum System. And then we performed the first meta-analysis focused on the genetic affinity between Asian Neolithic∼Iron Age ancients and modern northern-Han Chinese by combining mitochondrial variations in 417 ancient individuals from 13 different archeological sites and 812 modern individuals, as well as Y-chromosomal variations in 114 ancient individuals from 12 Neolithic∼Iron Age sites and 2,810 modern subjects. We finally genotyped 643,897 genome-wide nucleotide polymorphisms (SNPs) in 20 Shanxi Han individuals and combined with 1,927 modern humans and 40 Eurasian ancient genomes to explore the genetic structure and admixture of northern-Han Chinese. We addressed genetic legacy, population structure and phylogenetic relationship of northern-Han Chinese via various analyses. Our population genetic results from five different reference datasets indicated that Shanxi Han shares a closer phylogenetic relationship with northern-neighbors and southern ethnically close groups than with Uyghur and Tibetan. Genome-wide variations revealed that modern northern-Han derived their ancestry from Yakut-related population (25.2%) and She-related population (74.8%). Summarily, the genetic mixing that led to the emergence of a Han Chinese ethnicity occurred at a very early period, probably in Neolithic times, and this mixing involved an ancient Tibeto-Burman population and a local pre-Sinitic population, which may have been linguistically Altaic.

RevDate: 2020-01-08

Översti S, Majander K, Salmela E, et al (2019)

Human mitochondrial DNA lineages in Iron-Age Fennoscandia suggest incipient admixture and eastern introduction of farming-related maternal ancestry.

Scientific reports, 9(1):16883.

Human ancient DNA studies have revealed high mobility in Europe's past, and have helped to decode the human history on the Eurasian continent. Northeastern Europe, especially north of the Baltic Sea, however, remains less well understood largely due to the lack of preserved human remains. Finland, with a divergent population history from most of Europe, offers a unique perspective to hunter-gatherer way of life, but thus far genetic information on prehistoric human groups in Finland is nearly absent. Here we report 103 complete ancient mitochondrial genomes from human remains dated to AD 300-1800, and explore mtDNA diversity associated with hunter-gatherers and Neolithic farmers. The results indicate largely unadmixed mtDNA pools of differing ancestries from Iron-Age on, suggesting a rather late genetic shift from hunter-gatherers towards farmers in North-East Europe. Furthermore, the data suggest eastern introduction of farmer-related haplogroups into Finland, contradicting contemporary genetic patterns in Finns.

RevDate: 2019-11-26

Wasef S, Subramanian S, O'Rorke R, et al (2019)

Mitogenomic diversity in Sacred Ibis Mummies sheds light on early Egyptian practices.

PloS one, 14(11):e0223964.

The ancient catacombs of Egypt harbor millions of well-preserved mummified Sacred Ibis (Threskiornis aethiopicus) dating from ~600BC. Although it is known that a very large number of these 'votive' mummies were sacrificed to the Egyptian God Thoth, how the ancient Egyptians obtained millions of these birds for mummification remains unresolved. Ancient Egyptian textual evidences suggest they may have been raised in dedicated large-scale farms. To investigate the most likely method used by the priests to secure birds for mummification, we report the first study of complete mitochondrial genomes of 14 Sacred Ibis mummies interred ~2500 years ago. We analysed and compared the mitogenomic diversity among Sacred Ibis mummies to that found in modern Sacred Ibis populations from throughout Africa. The ancient birds show a high level of genetic variation comparable to that identified in modern African populations, contrary to the suggestion in ancient hieroglyphics (or ancient writings) of centralized industrial scale farming of sacrificial birds. This suggests a sustained short-term taming of the wild migratory Sacred Ibis for the ritual yearly demand.

RevDate: 2019-11-15

Swift JA, Bunce M, Dortch J, et al (2019)

Micro Methods for Megafauna: Novel Approaches to Late Quaternary Extinctions and Their Contributions to Faunal Conservation in the Anthropocene.

Bioscience, 69(11):877-887.

Drivers of Late Quaternary megafaunal extinctions are relevant to modern conservation policy in a world of growing human population density, climate change, and faunal decline. Traditional debates tend toward global solutions, blaming either dramatic climate change or dispersals of Homo sapiens to new regions. Inherent limitations to archaeological and paleontological data sets often require reliance on scant, poorly resolved lines of evidence. However, recent developments in scientific technologies allow for more local, context-specific approaches. In the present article, we highlight how developments in five such methodologies (radiocarbon approaches, stable isotope analysis, ancient DNA, ancient proteomics, microscopy) have helped drive detailed analysis of specific megafaunal species, their particular ecological settings, and responses to new competitors or predators, climate change, and other external phenomena. The detailed case studies of faunal community composition, extinction chronologies, and demographic trends enabled by these methods examine megafaunal extinctions at scales appropriate for practical understanding of threats against particular species in their habitats today.

RevDate: 2020-01-08
CmpDate: 2019-12-02

González-Oliver A, Pineda-Vázquez D, Garfias-Morales E, et al (2018)

Genetic Overview of the Maya Populations: Mitochondrial DNA Haplogroups.

Human biology, 90(4):281-300.

We identified mitochondrial DNA haplogroups A, B, C, and D in 75 present-day Maya individuals, 24 Maya individuals of the colonial period, and 1 pre-Columbian Maya individual from Quintana Roo, Mexico. We examined these data together with those of 21 Maya populations reported in the literature, comprising 647 present-day Maya individuals and 71 ancient Maya individuals. A demographic study based on analysis of fertility and endogamy was carried out in two modern Maya populations to identify cultural factors that influence the mitochondrial haplogroup genetic diversity. Most present-day and ancient Maya populations show a distribution pattern of mitochondrial haplogroup frequencies A, C, B, and D in decreasing order, with haplogroup D absent in several populations. Considering only modern Maya populations with at least 50 individuals analyzed, the present-day Tzotzil and Lacandon populations from Chiapas show the highest and lowest genetic diversity, 0.706 and 0.025, respectively. Our results show small genetic differences between the Maya populations, with the exception of the present-day Tojolabal and Lacandon populations from Chiapas. The present-day Lacandon population from Chiapas differs from other Maya populations in showing almost only haplogroup A. This result suggests a long history of isolation and endogamy as well as a possible founder effect inside the Lacandonian rain forest. The contemporary Tojolabal population is the only one with an unusual mitochondrial haplogroup pattern, exhibiting a frequency of haplogroup B higher than A and the absence of haplogroup C. With a small sample size, the pre-Columbian Copán Maya show a high content of haplogroup C and a low frequency of haplogroup D. The genetic homogeneity of the Maya populations is indicative of a common origin and nearly continuous gene flow in the long term within a general isolation of the whole group, in contrast to the Nahua populations that had different origins. Our demographic study showed high fertility rates and high levels of endogamy in the present-day Maya populations from Quintana Roo that are consistent with their general low genetic diversity. We propose that the genetic similarity among ancient and present-day Maya populations persists due to a strong sense of social cohesion and identity that impacts their marriage practices, keeping this cultural group isolated. These factors have constrained gene flow inside the Maya region and have impeded the differentiation among the Maya. Discernment of genetic differentiation within the peninsula is constrained by the lack of sampling documentation in the literature.

RevDate: 2019-11-11

Nieves-Colón MA, Pestle WJ, Reynolds AW, et al (2019)

Ancient DNA reconstructs the genetic legacies of pre-contact Puerto Rico communities.

Molecular biology and evolution pii:5618728 [Epub ahead of print].

Indigenous peoples have occupied the island of Puerto Rico since at least 3000 B.C. Due to the demographic shifts that occurred after European contact, the origin(s) of these ancient populations, and their genetic relationship to present-day islanders, are unclear. We use ancient DNA to characterize the population history and genetic legacies of pre-contact Indigenous communities from Puerto Rico. Bone, tooth and dental calculus samples were collected from 124 individuals from three pre-contact archaeological sites: Tibes, Punta Candelero and Paso del Indio. Despite poor DNA preservation, we used target enrichment and high-throughput sequencing to obtain complete mitochondrial genomes (mtDNA) from 45 individuals and autosomal genotypes from two individuals. We found a high proportion of Native American mtDNA haplogroups A2 and C1 in the pre-contact Puerto Rico sample (40% and 44%, respectively). This distribution, as well as the haplotypes represented, support a primarily Amazonian South American origin for these populations, and mirrors the Native American mtDNA diversity patterns found in present-day islanders. Three mtDNA haplotypes from pre-contact Puerto Rico persist among Puerto Ricans and other Caribbean islanders, indicating that present-day populations are reservoirs of pre-contact mtDNA diversity. Lastly, we find similarity in autosomal ancestry patterns between pre-contact individuals from Puerto Rico and the Bahamas, suggesting a shared component of Indigenous Caribbean ancestry with close affinity to South American populations. Our findings contribute to a more complete reconstruction of pre-contact Caribbean population history and explore the role of Indigenous peoples in shaping the biocultural diversity of present-day Puerto Ricans and other Caribbean islanders.

RevDate: 2020-01-24
CmpDate: 2020-01-24

Liddicoat C, Sydnor H, Cando-Dumancela C, et al (2020)

Naturally-diverse airborne environmental microbial exposures modulate the gut microbiome and may provide anxiolytic benefits in mice.

The Science of the total environment, 701:134684.

Growing epidemiological evidence links natural green space exposure with a range of health benefits, including for mental health. Conversely, greater urbanisation associates with increased risk of mental health disorders. Microbiomes are proposed as an important but understudied link that may help explain many green space-human health associations. However, there remains a lack of controlled experimental evidence testing possible beneficial effects from passive exposure to natural biodiversity via airborne microbiota. Previous mouse model studies have used unrealistic environmental microbial exposures-including excessive soil and organic matter contact, feed supplements and injections-to demonstrate host microbiota, immune biomarker, and behavioural changes. Here, in a randomised controlled experiment, we demonstrate that realistic exposures to trace-level dust from a high biodiversity soil can change mouse gut microbiota, in comparison to dust from low biodiversity soil or no soil (control) (n = 54 total mice, comprising 3 treatments × 18 mice, with 9 females + 9 males per group). Furthermore, we found a nominal soil-derived anaerobic spore-forming butyrate-producer, Kineothrix alysoides, was supplemented to a greater extent in the gut microbiomes of high biodiversity treatment mice. Also, increasing relative abundance of this rare organism correlated with reduced anxiety-like behaviour in the most anxious mice. Our results point to an intriguing new hypothesis: that biodiverse soils may represent an important supplementary source of butyrate-producing bacteria capable of resupplying the mammalian gut microbiome, with potential for gut health and mental health benefits. Our findings have potential to inform cost-effective population health interventions through microbiome-conscious green space design and, ultimately, the mainstreaming of biodiversity into health care.

RevDate: 2019-12-22

Wolinsky H (2019)

Ancient DNA and contemporary politics: The analysis of ancient DNA challenges long-held beliefs about identity and history with potential for political abuse.

EMBO reports, 20(12):e49507.

The sequencing and analysis of ancient human DNA has helped to rewrite human history. But it is also tempting politicians, nationalists and supremacists to abuse this research for their agendas.

RevDate: 2019-11-19

Serra-Vidal G, Lucas-Sanchez M, Fadhlaoui-Zid K, et al (2019)

Heterogeneity in Palaeolithic Population Continuity and Neolithic Expansion in North Africa.

Current biology : CB, 29(22):3953-3959.e4.

North Africa is located at the crossroads of the Mediterranean Sea, the Middle East, and the Sahara Desert. Extensive migrations and gene flow in the region have shaped many different cultures and ancestral genetic components through time [1-6]. DNA data from ancient Moroccan sites [7, 8] has recently shed some light to the population continuity-versus-replacement debate, i.e., the question of whether current North African populations descend from Palaeolithic groups or, on the contrary, subsequent migrations swept away all pre-existing genetic signal in the region. In the present study, we analyze 21 complete North African genomes and compare them with extant and ancient genome data in order to address the demographic continuity-versus-replacement debate, to assess whether these demographic events were homogeneous (including Berber and Arabic-speaking groups), and to explore the effect of Neolithization and posterior migration waves. The North African genetic pool is defined as a melting pot of genetic components, including an endemic North African Epipalaeolithic component at low frequency that forms a declining gradient from Western to Eastern North Africa. This scenario is consistent with Neolithization having shaped most of the current genetic variation in the region when compared to posterior back-to-North-Africa migration waves such as the Arabization. A common and distinct genetic history of the region is shown, with internal different proportions of genetic components owing to differential admixture with surrounding groups as well as to genetic drift due to isolation and endogamy in certain populations.

RevDate: 2019-11-27

Larsson P, von Seth J, Hagen IJ, et al (2019)

Consequences of past climate change and recent human persecution on mitogenomic diversity in the arctic fox.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 374(1788):20190212.

Ancient DNA provides a powerful means to investigate the timing, rate and extent of population declines caused by extrinsic factors, such as past climate change and human activities. One species probably affected by both these factors is the arctic fox, which had a large distribution during the last glaciation that subsequently contracted at the start of the Holocene. More recently, the arctic fox population in Scandinavia went through a demographic bottleneck owing to human persecution. To investigate the consequences of these processes, we generated mitogenome sequences from a temporal dataset comprising Pleistocene, historical and modern arctic fox samples. We found no evidence that Pleistocene populations in mid-latitude Europe or Russia contributed to the present-day gene pool of the Scandinavian population, suggesting that postglacial climate warming led to local population extinctions. Furthermore, during the twentieth-century bottleneck in Scandinavia, at least half of the mitogenome haplotypes were lost, consistent with a 20-fold reduction in female effective population size. In conclusion, these results suggest that the arctic fox in mainland Western Europe has lost genetic diversity as a result of both past climate change and human persecution. Consequently, it might be particularly vulnerable to the future challenges posed by climate change. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'

RevDate: 2019-12-31
CmpDate: 2019-12-31

Gaget V, Hobson P, Keulen A, et al (2020)

Toolbox for the sampling and monitoring of benthic cyanobacteria.

Water research, 169:115222.

Benthic cyanobacteria are a nuisance because they produce highly potent toxins and taste and odour compounds. Despite this, benthic cyanobacteria remain far less studied than their planktonic counterparts. For example, little is known about their growth or the seasonality of their secondary metabolite production. Moreover, sampling and monitoring techniques commonly used for the survey of planktonic species are not necessarily applicable to benthic forms. This study aimed to develop and validate a new sampling device for the routine monitoring of benthic mats. Molecular monitoring techniques were established and validated on environmental samples collected in a South Australian reservoir (SA-L2). A total of eight qPCR assays were applied to samples in order to track seasonal variations in cyanobacteria concentrations and associated secondary metabolite production. Next Generation Sequencing was utilised to conduct a microbial community composition analysis and to select the most appropriate substrate material for the sampling of benthic cyanobacteria. The concentration of the secondary metabolites geosmin and 2-methyl-isoborneol were quantified using High-Performance Liquid Chromatography, and concentrations of key nutrients (N, P) were quantified in water samples. The sampling device designed proved efficient and easy to use in the field. The qPCR assay designed for the amplification of the cyanobacterial MIB synthase had a high efficiency with a minimum limit of quantification of 4 cell-equivalents per reaction and identified a potential source of MIB in SA-L2 Reservoir. The peak season for benthic growth and secondary metabolite production was observed in spring. Proportionally, 35% of the variability in water geosmin concentrations can be explained by benthic actinobacterial and cyanobacterial activity, showing that freshwater benthic mats represent a significant source of taste and odour compounds.

RevDate: 2019-10-27

Poma A, Cesare P, Bonfigli A, et al (2019)

Analysis of ancient mtDNA from the medieval archeological site of Amiternum (L'Aquila), central Italy.

Heliyon, 5(10):e02586.

Study of ancient DNA makes it possible to analyze genetic relationships between individuals and populations of past and present. In this paper we have analyzed remains of human bones, dating back to the 8th-10th century AD, from the burials found in the Cathedral of Santa Maria in Civitate, archaeological site of Amiternum, L'Aquila, Italy. As a genetic marker, the hypervariable region 1 of mitochondrial DNA (HVR1) was selected. To obtain reliable sequences from the hypervariable region 1 of mtDNA (HVR1) were performed: multiple extractions, template quantification and cloning of PCR products. The sequences obtained were compared with Anderson's sequence for the identification of polymorphisms (SNP) and haplogroups. The data obtained were analyzed with various software and phylogenetic methods. For the comparison between populations, ancient and modern sequences found in databases and literature have been used. This work provides preliminary information on the correlation between the population of Amiternum, the migrant populations transited and/or established in the territory of Amiternum such as Byzantines, Longobards (Lombards), which dominated the Italian peninsula between 568 and 774 AD, and the current populations of Italy. The study of haplogroups, the analysis of genetic variability and phylogenesis studies on the sequences considered show a genetic closeness between the individuals of Amiternum, the current population of central-northern Italy and the Germanic tribe of Longobards, however, also highlights genetic traits of Byzantines in some samples of Amiternum. Using the analysis of amelogenin gene fragments, we successfully determined the sex of the bone remains on all samples.

RevDate: 2019-10-22

Liu Y, Weyrich LS, B Llamas (2019)

More arrows in the ancient DNA quiver: use of paleoepigenomes and paleomicrobiomes to investigate animal adaptation to environment.

Molecular biology and evolution pii:5602326 [Epub ahead of print].

Whether and how epigenetic mechanisms and the microbiome play a role in mammalian adaptation raised considerable attention and controversy, mainly because they have the potential to add new insights into the Modern Synthesis. Recent attempts to reconcile neo-Darwinism and neo-Lamarckism in a unified theory of molecular evolution give epigenetic mechanisms and microbiome a prominent role. However, supporting empirical data is still largely missing. Because experimental studies using extant animals can hardly be done over evolutionary timescales, we propose that advances in ancient DNA techniques provide a valid alternative. In this piece, we evaluate: (1) the possible roles of epigenomes and microbiomes in animal adaptation; (2) advances in the retrieval of paleoepigenome and paleomicrobiome data using ancient DNA techniques; and (3) the plasticity of either and interactions between the epigenome and the microbiome, while emphasising that it is essential to take both into account, as well as the underlying genetic factors that may confound the findings. We propose that advanced ancient DNA techniques should be applied to a wide range of past animals, so novel dynamics in animal evolution and adaption can be revealed.

RevDate: 2020-01-08

Raghavan M, Schroeder H, AS Malaspinas (2019)

An Ancient Genome from the Indus Valley Civilization.

Cell, 179(3):586-588.

Shinde et al. report the first genome-wide data from an ancient individual from the Indus Valley Civilization in South Asia. Their findings have implications for the origins and spread of farming and Indo-European languages in the region and the makings of the South Asian gene pool.

RevDate: 2020-01-08

Shamoon-Pour M, Li M, DA Merriwether (2019)

Rare human mitochondrial HV lineages spread from the Near East and Caucasus during post-LGM and Neolithic expansions.

Scientific reports, 9(1):14751.

Of particular significance to human population history in Eurasia are the migratory events that connected the Near East to Europe after the Last Glacial Maximum (LGM). Utilizing 315 HV*(xH,V) mitogenomes, including 27 contemporary lineages first reported here, we found the genetic signatures for distinctive movements out of the Near East and South Caucasus both westward into Europe and eastward into South Asia. The parallel phylogeographies of rare, yet widely distributed HV*(xH,V) subclades reveal a connection between the Italian Peninsula and South Caucasus, resulting from at least two (post-LGM, Neolithic) waves of migration. Many of these subclades originated in a population ancestral to contemporary Armenians and Assyrians. One such subclade, HV1b-152, supports a postexilic, northern Mesopotamian origin for the Ashkenazi HV1b2 lineages. In agreement with ancient DNA findings, our phylogenetic analysis of HV12 and HV14, the two exclusively Asian subclades of HV*(xH,V), point to the migration of lineages originating in Iran to South Asia before and during the Neolithic period. With HV12 being one of the oldest HV subclades, our results support an origin of HV haplogroup in the region defined by Western Iran, Mesopotamia, and the South Caucasus, where the highest prevalence of HV has been found.

RevDate: 2019-12-21

Guitor AK, Raphenya AR, Klunk J, et al (2019)

Capturing the Resistome: a Targeted Capture Method To Reveal Antibiotic Resistance Determinants in Metagenomes.

Antimicrobial agents and chemotherapy, 64(1): pii:AAC.01324-19.

Identification of the nucleotide sequences encoding antibiotic resistance elements and determination of their association with antibiotic resistance are critical to improve surveillance and monitor trends in antibiotic resistance. Current methods to study antibiotic resistance in various environments rely on extensive deep sequencing or laborious culturing of fastidious organisms, both of which are heavily time-consuming operations. An accurate and sensitive method to identify both rare and common resistance elements in complex metagenomic samples is needed. Referencing the sequences in the Comprehensive Antibiotic Resistance Database, we designed a set of 37,826 probes to specifically target over 2,000 nucleotide sequences associated with antibiotic resistance in clinically relevant bacteria. Testing of this probe set on DNA libraries generated from multidrug-resistant bacteria to selectively capture resistance genes reproducibly produced higher numbers of reads on target at a greater length of coverage than shotgun sequencing. We also identified additional resistance gene sequences from human gut microbiome samples that sequencing alone was not able to detect. Our method to capture the resistome enables a sensitive means of gene detection in diverse environments where genes encoding antibiotic resistance represent less than 0.1% of the metagenome.

RevDate: 2019-11-22

Tett A, Huang KD, Asnicar F, et al (2019)

The Prevotella copri Complex Comprises Four Distinct Clades Underrepresented in Westernized Populations.

Cell host & microbe, 26(5):666-679.e7.

Prevotella copri is a common human gut microbe that has been both positively and negatively associated with host health. In a cross-continent meta-analysis exploiting >6,500 metagenomes, we obtained >1,000 genomes and explored the genetic and population structure of P. copri. P. copri encompasses four distinct clades (>10% inter-clade genetic divergence) that we propose constitute the P. copri complex, and all clades were confirmed by isolate sequencing. These clades are nearly ubiquitous and co-present in non-Westernized populations. Genomic analysis showed substantial functional diversity in the complex with notable differences in carbohydrate metabolism, suggesting that multi-generational dietary modifications may be driving reduced prevalence in Westernized populations. Analysis of ancient metagenomes highlighted patterns of P. copri presence consistent with modern non-Westernized populations and a clade delineation time pre-dating human migratory waves out of Africa. These findings reveal that P. copri exhibits a high diversity that is underrepresented in Western-lifestyle populations.

RevDate: 2020-01-08
CmpDate: 2019-11-28

Crump SE, Miller GH, Power M, et al (2019)

Arctic shrub colonization lagged peak postglacial warmth: Molecular evidence in lake sediment from Arctic Canada.

Global change biology, 25(12):4244-4256.

Arctic shrubification is an observable consequence of climate change, already resulting in ecological shifts and global-scale climate feedbacks including changes in land surface albedo and enhanced evapotranspiration. However, the rate at which shrubs can colonize previously glaciated terrain in a warming world is largely unknown. Reconstructions of past vegetation dynamics in conjunction with climate records can provide critical insights into shrubification rates and controls on plant migration, but paleoenvironmental reconstructions based on pollen may be biased by the influx of exotic pollen to tundra settings. Here, we reconstruct past plant communities using sedimentary ancient DNA (sedaDNA), which has a more local source area than pollen. We additionally reconstruct past temperature variability using bacterial cell membrane lipids (branched glycerol dialkyl glycerol tetraethers) and an aquatic productivity indicator (biogenic silica) to evaluate the relative timing of postglacial ecological and climate changes at a lake on southern Baffin Island, Arctic Canada. The sedaDNA record tightly constrains the colonization of dwarf birch (Betula, a thermophilous shrub) to 5.9 ± 0.1 ka, ~3 ka after local deglaciation as determined by cosmogenic 10 Be moraine dating and >2 ka later than Betula pollen is recorded in nearby lake sediment. We then assess the paleovegetation history within the context of summer temperature and find that paleotemperatures were highest prior to 6.3 ka, followed by cooling in the centuries preceding Betula establishment. Together, these molecular proxies reveal that Betula colonization lagged peak summer temperatures, suggesting that inefficient dispersal, rather than climate, may have limited Arctic shrub migration in this region. In addition, these data suggest that pollen-based climate reconstructions from high latitudes, which rely heavily on the presence and abundance of pollen from thermophilous taxa like Betula, can be compromised by both exotic pollen fluxes and vegetation migration lags.

RevDate: 2019-11-01

Cox SL, Ruff CB, Maier RM, et al (2019)

Genetic contributions to variation in human stature in prehistoric Europe.

Proceedings of the National Academy of Sciences of the United States of America, 116(43):21484-21492.

The relative contributions of genetics and environment to temporal and geographic variation in human height remain largely unknown. Ancient DNA has identified changes in genetic ancestry over time, but it is not clear whether those changes in ancestry are associated with changes in height. Here, we directly test whether changes over the past 38,000 y in European height predicted using DNA from 1,071 ancient individuals are consistent with changes observed in 1,159 skeletal remains from comparable populations. We show that the observed decrease in height between the Early Upper Paleolithic and the Mesolithic is qualitatively predicted by genetics. Similarly, both skeletal and genetic height remained constant between the Mesolithic and Neolithic and increased between the Neolithic and Bronze Age. Sitting height changes much less than standing height-consistent with genetic predictions-although genetics predicts a small post-Neolithic increase that is not observed in skeletal remains. Geographic variation in stature is also qualitatively consistent with genetic predictions, particularly with respect to latitude. Finally, we hypothesize that an observed decrease in genetic heel bone mineral density in the Neolithic reflects adaptation to the decreased mobility indicated by decreased femoral bending strength. This study provides a model for interpreting phenotypic changes predicted from ancient DNA and demonstrates how they can be combined with phenotypic measurements to understand the relative contribution of genetic and developmentally plastic responses to environmental change.

RevDate: 2019-10-23

Malmström H, Günther T, Svensson EM, et al (2019)

The genomic ancestry of the Scandinavian Battle Axe Culture people and their relation to the broader Corded Ware horizon.

Proceedings. Biological sciences, 286(1912):20191528.

The Neolithic period is characterized by major cultural transformations and human migrations, with lasting effects across Europe. To understand the population dynamics in Neolithic Scandinavia and the Baltic Sea area, we investigate the genomes of individuals associated with the Battle Axe Culture (BAC), a Middle Neolithic complex in Scandinavia resembling the continental Corded Ware Culture (CWC). We sequenced 11 individuals (dated to 3330-1665 calibrated before common era (cal BCE)) from modern-day Sweden, Estonia, and Poland to 0.26-3.24× coverage. Three of the individuals were from CWC contexts and two from the central-Swedish BAC burial 'Bergsgraven'. By analysing these genomes together with the previously published data, we show that the BAC represents a group different from other Neolithic populations in Scandinavia, revealing stratification among cultural groups. Similar to continental CWC, the BAC-associated individuals display ancestry from the Pontic-Caspian steppe herders, as well as smaller components originating from hunter-gatherers and Early Neolithic farmers. Thus, the steppe ancestry seen in these Scandinavian BAC individuals can be explained only by migration into Scandinavia. Furthermore, we highlight the reuse of megalithic tombs of the earlier Funnel Beaker Culture (FBC) by people related to BAC. The BAC groups likely mixed with resident middle Neolithic farmers (e.g. FBC) without substantial contributions from Neolithic foragers.

RevDate: 2019-10-08

Fiumi Sermattei I, Traversari M, Serventi P, et al (2019)

Pope Leo XII's death: the twist to a longstanding dispute by novel historical documents and paleopathographic analysis.

Homo : internationale Zeitschrift fur die vergleichende Forschung am Menschen [Epub ahead of print].

Although the practice of autopsy on the Pope's corpse was performed from the 16th century, autopsy reports are only rarely analysed, and never with the aim of investigating the real causes of the death from a concomitant medical and historical point of view. Here, for the first time, we report on the discovery of new unpublished documents from the Vatican Secret Archives and their investigation by a scientific and inter-disciplinary approach. This analysis allows us to draw new conclusions on the true cause of Leo XII's mysterious death. His sudden death, that occurred on February 10th, 1829 after a short illness, particularly struck the public. Suspicions of poisoning or surgeon's guilt or inexperience and even the shadow of a venereal disease, contributed to create a "black legend" on his pontificate and death. On the contrary, the present paleopathographic analysis points toward a new conclusion. The regular use of catheterization with a silver syringe provided an easy access for bacterial superinfection, confirmed by the observed early emphysematous stage of the corpse. So, the most substantiated hypothesis concerning the cause of Leo XII's death indicates a severe form of sepsis, exacerbated by a weakened state due to chronic hemorrhoids.

RevDate: 2019-10-07

Kowal E, B Llamas (2019)

Race in a genome: long read sequencing, ethnicity-specific reference genomes and the shifting horizon of race.

Journal of anthropological sciences = Rivista di antropologia : JASS, 97: [Epub ahead of print].

The sequencing of the human genome at the turn of the 21st century was hailed as revealing the overwhelming genetic similarity of human groups. Scholars of genomics have critiqued the subsequent persistence of race-based genetic science, but were reassured that the wide availability of gene sequencing would end the use of race as a proxy for genetic difference. Once an individual's whole gene sequence could be read, they hoped, their ethnoracial classification would become redundant. At the same time, genome science was recognising that the differences between human genomes went beyond the genome sequence to the structure of the genome itself. 'Structural variation' between genomes, including insertions, deletions, translocations, inversions, and copy number variations, mean that the 'universal' reference genome used for genome sequencing is not so universal. As conventional, 'short-read' sequencing wrongly assumes that all genomes have the same structure, significant genetic variation can be missed. This paper examines the twin phenomena that have been posed as a solution to the biases of short-read sequencing: 'long-read' sequencing and 'ethnicity-specific reference genomes'. Long-read sequencing is a method of generating a genome sequence that can be assembled de novo rather than relying on the reference genome. In recent years, a number of countries including China, Korea, and Denmark have used long-read sequencing and de novo assembly to develop 'national' reference genomes. Our analysis of one ethnicity-specific reference genome project, the Korean Reference Genome (KOREF), finds that it unduly emphasises the importance of population structural variation, framed in nationalist terms, and discounts the importance of individual structural variation. We argue that the intellectual labour required to make a Korean reference genome a coherent concept works to extend the horizon of race, prolonging the temporality of the 'meantime' in which race remains a seemingly valid concept in genomic science.

RevDate: 2019-10-23

Robson HK, Skipitytė R, Piličiauskienė G, et al (2019)

Diet, cuisine and consumption practices of the first farmers in the southeastern Baltic.

Archaeological and anthropological sciences, 11(8):4011-4024.

With the arrival of the Early Neolithic Globular Amphora and Corded Ware cultures into the southeastern Baltic, ca. 2900/2800-2400 cal BC, a new type of economy was introduced, animal husbandry. However, the degree to which this transformed the subsistence economy is unknown. Here, we conducted organic residue analyses of 64 ceramic vessels to identify their contents. The vessels were sampled from 10 Lithuanian archaeological sites dating across the Subneolithic-Neolithic transition to the Early Bronze Age (ca. 2900/2800-1300 cal BC). Our results demonstrate that regardless of location or vessel type, many ceramics were used to process aquatic resources. Against our expectations, this association continued even after marked economic change concurrent with the migration of pastoralists from central and southeastern Europe, as evidenced by recent ancient DNA analysis of human remains. Moreover, we observed dairy fats in pottery from all cultures of the Early Neolithic (i.e. Rzucewo, Globular Amphora and Corded Ware) but unlike other regions of Europe, it seems that these were incorporated into indigenous culinary practices. Furthermore, some vessels were used to process plant foods, and others may have been used for the production and/or storage of birch bark tar. However, evidence for domesticated plant processing, for example millet, was absent. We show that organic residue analysis of pottery provides a different picture of past consumption patterns compared to the stable isotope analysis of human remains from isolated burials where a clear dietary shift is evident.

RevDate: 2019-12-02

Jones R, Velasco MS, Harris LG, et al (2019)

Resolving a clinical tuberculosis outbreak using palaeogenomic genome reconstruction methodologies.

Tuberculosis (Edinburgh, Scotland), 119:101865.

This study describes the analysis of DNA from heat-killed (boilate) isolates of Mycobacterium tuberculosis from two UK outbreaks where DNA was of sub-optimal quality for the standard methodologies routinely used in microbial genomics. An Illumina library construction method developed for sequencing ancient DNA was successfully used to obtain whole genome sequences, allowing analysis of the outbreak by gene-by-gene MLST, SNP mapping and phylogenetic analysis. All cases were spoligotyped to the same Haarlem H1 sub-lineage. This is the first described application of ancient DNA library construction protocols to allow whole genome sequencing of a clinical tuberculosis outbreak. Using this method it is possible to obtain epidemiologically meaningful data even when DNA is of insufficient quality for standard methods.

RevDate: 2019-11-19

Yankova I, Marinov M, Neov B, et al (2019)

Evidence for Early European Neolithic Dog Dispersal: New Data on Southeastern European Subfossil Dogs from the Prehistoric and Antiquity Ages.

Genes, 10(10):.

The history of dog domestication is still under debate, but it is doubtless the process of an ancient partnership between dogs (Canis familiaris) and humans. Although data on ancient DNA for dog diversity are still incomplete, it is clear that several regional dog populations had formed in Eurasia up to the Holocene. During the Neolithic Revolution and the transition from hunter-gatherer to farmer societies, followed by civilization changes in the Antiquity period, the dog population structure also changed. This process was due to replacement with newly formed dog populations. In this study, we present for the first time mitochondrial data of ancient dog remains from the Early Neolithic (8000 years before present (BP)) to Late Antiquity (up to 3th century AD) from southeastern Europe (the Balkans). A total of 16 samples were analyzed, using the mitochondrial D-loop region (HVR1). The results show the presence of A (70%) and B (25%) clades throughout the Early and Late Neolithic Period. In order to clarify the position of our results within the ancient dog population in Eneolithic Eurasia, we performed phylogenetic analysis with the available genetic data sets. This data showed a similarity of the ancient Bulgarian dogs to Italian (A, B, and C clades) and Iberian (clades A and C) dogs' populations. A clear border can be seen between southern European genetic dog structure, on the one hand, and on the other hand, central-western (clade C), eastern (clade D) and northern Europe (clades A and C). This corresponds to genetic data for European humans during the same period, without admixture between dog populations. Also, our data have shown the presence of clade B in ancient Eurasia. This is not unexpected, as the B haplogroup is widely distributed in extant Balkan dogs and wolves. The presence of this clade both in dogs and in wolves on the Balkans may be explained with hybridization events before the Neolithic period. The spreading of this clade across Europe, together with the A clade, is related to the possible dissemination of newly formed dog breeds from Ancient Greece, Thrace, and the Roman Empire.

RevDate: 2019-10-23

Morley MW, Goldberg P, Uliyanov VA, et al (2019)

Hominin and animal activities in the microstratigraphic record from Denisova Cave (Altai Mountains, Russia).

Scientific reports, 9(1):13785.

Denisova Cave in southern Siberia uniquely contains evidence of occupation by a recently discovered group of archaic hominins, the Denisovans, starting from the middle of the Middle Pleistocene. Artefacts, ancient DNA and a range of animal and plant remains have been recovered from the sedimentary deposits, along with a few fragmentary fossils of Denisovans, Neanderthals and a first-generation Neanderthal-Denisovan offspring. The deposits also contain microscopic traces of hominin and animal activities that can provide insights into the use of the cave over the last 300,000 years. Here we report the results of a micromorphological study of intact sediment blocks collected from the Pleistocene deposits in the Main and East Chambers of Denisova Cave. The presence of charcoal attests to the use of fire by hominins, but other evidence of their activities preserved in the microstratigraphic record are few. The ubiquitous occurrence of coprolites, which we attribute primarily to hyenas, indicates that the site was visited for much of its depositional history by cave-dwelling carnivores. Microscopic traces of post-depositional diagenesis, bioturbation and incipient cryoturbation are observed in only a few regions of the deposit examined here. Micromorphology can help identify areas of sedimentary deposit that are most conducive to ancient DNA preservation and could be usefully integrated with DNA analyses of sediments at archaeological sites to illuminate features of their human and environmental history that are invisible to the naked eye.

RevDate: 2019-09-27

Wang C, Lu H, Zhang J, et al (2019)

Bulliform Phytolith Size of Rice and Its Correlation With Hydrothermal Environment: A Preliminary Morphological Study on Species in Southern China.

Frontiers in plant science, 10:1037.

In the last decade, our understanding of rice domestication has improved by new archaeological findings using advanced analytical techniques such as morphological and morphometric analyses on rice grains, spikelet bases and phytoliths, and ancient DNA analysis on rice remains. Previous studies have considered the size of rice bulliform phytoliths as a proxy for tracking the domestication process. These phytoliths are often abundant and well preserved in sediments, and their shape is under the control of numerous genes, which may shift toward larger sizes by genetic mutation in domestication. Therefore, it has been assumed that the bulliforms of domesticated rice are usually larger than those of wild ones; however, morphometric data supporting this assumption are lacking in the literature, thereby requiring additional evidence to test its veracity. In this study, the vertical and horizonal lengths of bulliform phytoliths were measured in four rice species (domesticated Oryza sativa and wild Oryza rufipogon, Oryza officinalis, and Oryza meyeriana) from different regions of southern China. We found that the bulliform morphometric data of wild and domesticated rice overlapped and that there was no statistically significant difference between them. Therefore, bulliform size could not be used as a diagnostic indicator to distinguish domesticated rice from wild species and is a supporting rather than conclusive proxy for determining the domesticated status of rice in archaeological research. We further found that larger rice bulliform sizes likely occurred at the locations with higher temperature, precipitation, and water levels, indicating hydrothermal environment is an alternative factor influencing the size of rice bulliform phytoliths. For further archaeological use of an increasing size trend of bulliform phytoliths to reveal the process of rice domestication, we present some suggestions for controlling the influence of hydrothermal factors. Even so, the combination of bulliform phytolith size with other established criteria is strongly suggested to provide precise identification of wild and domesticated rice in future research.

RevDate: 2019-09-27

Chen SG, Li J, Zhang F, et al (2019)

Different maternal lineages revealed by ancient mitochondrial genome of Camelus bactrianus from China.

Mitochondrial DNA. Part A, DNA mapping, sequencing, and analysis, 30(7):786-793.

Domestic Bactrian camel (Camelus bactrianus) used to be one of the most important livestock species in Chinese history, as well as the major transport carrier on the ancient Silk Road. However, archeological studies on Chinese C. bactrianus are still limited, and molecular biology research on this species is mainly focused on modern specimens. In this study, we retrieved the complete mitochondrial genome from a C. bactrianus specimen, which was excavated from northwestern China and dated at 1290-1180 cal. years before present (yBP). Phylogenetic analyses using 18 mitochondrial genomes indicated that the C. bactrianus clade was divided into two maternal lineages. The majority of samples originating from Iran to Japan and Mongolia belong to subclade A1, while our sample together with two Mongolian individuals formed the much smaller subclade A2. Furthermore, the divergence time of these two maternal lineages was estimated as 165 Kya (95% credibility interval 117-222 Kya), this might indicate that several different evolutionary lineages were incorporated into the domestic gene pool during the initial domestication process. Bayesian skyline plot (BSP) analysis suggest a slow increase in female effective population size of C. bactrianus from 5000 years ago, which corresponds to the beginning of domestication of C. bactrianus. The present study also revealed that there were extensive exchanges of genetic information among C. bactrianus populations in regions along the Silk Road.

RevDate: 2019-12-07

Tamm E, Di Cristofaro J, Mazières S, et al (2019)

Genome-wide analysis of Corsican population reveals a close affinity with Northern and Central Italy.

Scientific reports, 9(1):13581.

Despite being the fourth largest island in the Mediterranean basin, the genetic variation of Corsica has not been explored as exhaustively as Sardinia, which is situated only 11 km South. However, it is likely that the populations of the two islands shared, at least in part, similar demographic histories. Moreover, the relative small size of the Corsica may have caused genetic isolation, which, in turn, might be relevant under medical and translational perspectives. Here we analysed genome wide data of 16 Corsicans, and integrated with newly (33 individuals) and previously generated samples from West Eurasia and North Africa. Allele frequency, haplotype-based, and ancient genome analyses suggest that although Sardinia and Corsica may have witnessed similar isolation and migration events, the latter is genetically closer to populations from continental Europe, such as Northern and Central Italians.

RevDate: 2019-09-20

Ishiya K, Mizuno F, Wang L, et al (2019)

MitoIMP: A Computational Framework for Imputation of Missing Data in Low-Coverage Human Mitochondrial Genome.

Bioinformatics and biology insights, 13:1177932219873884 pii:10.1177_1177932219873884.

The incompleteness of partial human mitochondrial genome sequences makes it difficult to perform relevant comparisons among multiple resources. To deal with this issue, we propose a computational framework for deducing missing nucleotides in the human mitochondrial genome. We applied it to worldwide mitochondrial haplogroup lineages and assessed its performance. Our approach can deduce the missing nucleotides with a precision of 0.99 or higher in most human mitochondrial DNA lineages. Furthermore, although low-coverage mitochondrial genome sequences often lead to a blurred relationship in the multidimensional scaling analysis, our approach can correct this positional arrangement according to the corresponding mitochondrial DNA lineages. Therefore, our framework will provide a practical solution to compensate for the lack of genome coverage in partial and fragmented human mitochondrial genome sequences. In this study, we developed an open-source computer program, MitoIMP, implementing our imputation procedure. MitoIMP is freely available from https://github.com/omics-tools/mitoimp.

RevDate: 2019-12-11

Bennett EA, Crevecoeur I, Viola B, et al (2019)

Morphology of the Denisovan phalanx closer to modern humans than to Neanderthals.

Science advances, 5(9):eaaw3950 pii:aaw3950.

A fully sequenced high-quality genome has revealed in 2010 the existence of a human population in Asia, the Denisovans, related to and contemporaneous with Neanderthals. Only five skeletal remains are known from Denisovans, mostly molars; the proximal fragment of a fifth finger phalanx used to generate the genome, however, was too incomplete to yield useful morphological information. Here, we demonstrate through ancient DNA analysis that a distal fragment of a fifth finger phalanx from the Denisova Cave is the larger, missing part of this phalanx. Our morphometric analysis shows that its dimensions and shape are within the variability of Homo sapiens and distinct from the Neanderthal fifth finger phalanges. Thus, unlike Denisovan molars, which display archaic characteristics not found in modern humans, the only morphologically informative Denisovan postcranial bone identified to date is suggested here to be plesiomorphic and shared between Denisovans and modern humans.

RevDate: 2020-01-29
CmpDate: 2020-01-29

Menardo F, Duchêne S, Brites D, et al (2019)

The molecular clock of Mycobacterium tuberculosis.

PLoS pathogens, 15(9):e1008067.

The molecular clock and its phylogenetic applications to genomic data have changed how we study and understand one of the major human pathogens, Mycobacterium tuberculosis (MTB), the etiologic agent of tuberculosis. Genome sequences of MTB strains sampled at different times are increasingly used to infer when a particular outbreak begun, when a drug-resistant clone appeared and expanded, or when a strain was introduced into a specific region. Despite the growing importance of the molecular clock in tuberculosis research, there is a lack of consensus as to whether MTB displays a clocklike behavior and about its rate of evolution. Here we performed a systematic study of the molecular clock of MTB on a large genomic data set (6,285 strains), covering different epidemiological settings and most of the known global diversity. We found that sampling times below 15-20 years were often insufficient to calibrate the clock of MTB. For data sets where such calibration was possible, we obtained a clock rate between 1x10-8 and 5x10-7 nucleotide changes per-site-per-year (0.04-2.2 SNPs per-genome-per-year), with substantial differences between clades. These estimates were not strongly dependent on the time of the calibration points as they changed only marginally when we used epidemiological isolates (sampled in the last 40 years) or three ancient DNA samples (about 1,000 years old) to calibrate the tree. Additionally, the uncertainty and the discrepancies in the results of different methods were sometimes large, highlighting the importance of using different methods, and of considering carefully their assumptions and limitations.

RevDate: 2019-12-07
CmpDate: 2019-11-12

Cappellini E, Welker F, Pandolfi L, et al (2019)

Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny.

Nature, 574(7776):103-107.

The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa1. However, the irreversible post-mortem degradation2 of ancient DNA has so far limited its recovery-outside permafrost areas-to specimens that are not older than approximately 0.5 million years (Myr)3. By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I4, and suggested the presence of protein residues in fossils of the Cretaceous period5-although with limited phylogenetic use6. In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch7-9, using the proteome of dental enamel from a Stephanorhinus tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia)10. Molecular phylogenetic analyses place this Stephanorhinus as a sister group to the clade formed by the woolly rhinoceros (Coelodonta antiquitatis) and Merck's rhinoceros (Stephanorhinus kirchbergensis). We show that Coelodonta evolved from an early Stephanorhinus lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus Stephanorhinus is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel-which is the hardest tissue in vertebrates11, and is highly abundant in the fossil record-can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation.

RevDate: 2019-09-10

Moreno-Mayar JV, Korneliussen TS, Dalal J, et al (2019)

A likelihood method for estimating present-day human contamination in ancient male samples using low-depth X-chromosome data.

Bioinformatics (Oxford, England) pii:5554699 [Epub ahead of print].

MOTIVATION: The presence of present-day human contaminating DNA fragments is one of the challenges defining ancient DNA (aDNA) research. This is especially relevant to the ancient human DNA field where it is difficult to distinguish endogenous molecules from human contaminants due to their genetic similarity. Recently, with the advent of high-throughput sequencing and new aDNA protocols, hundreds of ancient human genomes have become available. Contamination in those genomes has been measured with computational methods often developed specifically for these empirical studies. Consequently, some of these methods have not been implemented and tested for general use while few are aimed at low-depth nuclear data, a common feature in aDNA datasets.

RESULTS: We develop a new X-chromosome-based maximum likelihood method for estimating present-day human contamination in low-depth sequencing data from male individuals. We implement our method for general use, assess its performance under conditions typical of ancient human DNA research, and compare it to previous nuclear data-based methods through extensive simulations. For low-depth data, we show that existing methods can produce unusable estimates or substantially underestimate contamination. In contrast, our method provides accurate estimates for a depth of coverage as low as 0.5× on the X-chromosome when contamination is below 25%. Moreover, our method still yields meaningful estimates in very challenging situations, i.e., when the contaminant and the target come from closely related populations or with increased error rates. With a running time below five minutes, our method is applicable to large scale aDNA genomic studies.

AVAILABILITY: The method is implemented in C++ and R and is available in github.com/sapfo/contaminationX and popgen.dk/angsd.

RevDate: 2019-10-23

Shinde V, Narasimhan VM, Rohland N, et al (2019)

An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers.

Cell, 179(3):729-735.e10.

We report an ancient genome from the Indus Valley Civilization (IVC). The individual we sequenced fits as a mixture of people related to ancient Iranians (the largest component) and Southeast Asian hunter-gatherers, a unique profile that matches ancient DNA from 11 genetic outliers from sites in Iran and Turkmenistan in cultural communication with the IVC. These individuals had little if any Steppe pastoralist-derived ancestry, showing that it was not ubiquitous in northwest South Asia during the IVC as it is today. The Iranian-related ancestry in the IVC derives from a lineage leading to early Iranian farmers, herders, and hunter-gatherers before their ancestors separated, contradicting the hypothesis that the shared ancestry between early Iranians and South Asians reflects a large-scale spread of western Iranian farmers east. Instead, sampled ancient genomes from the Iranian plateau and IVC descend from different groups of hunter-gatherers who began farming without being connected by substantial movement of people.

RevDate: 2020-01-19

Littleford-Colquhoun BL, Weyrich LS, Kent N, et al (2019)

City life alters the gut microbiome and stable isotope profiling of the eastern water dragon (Intellagama lesueurii).

Molecular ecology, 28(20):4592-4607.

Urbanisation is one of the most significant threats to biodiversity, due to the rapid and large-scale environmental alterations it imposes on the natural landscape. It is, therefore, imperative that we understand the consequences of and mechanisms by which, species can respond to it. In recent years, research has shown that plasticity of the gut microbiome may be an important mechanism by which animals can adapt to environmental change, yet empirical evidence of this in wild non-model species remains sparse. Using an empirical replicated study system, we show that city life alters the gut microbiome and stable isotope profiling of a wild native non-model species - the eastern water dragon (Intellagama lesueurii) in Queensland, Australia. City dragons exhibit a more diverse gut microbiome than their native habitat counterparts and show gut microbial signatures of a high fat and plant rich diet. Additionally, we also show that city dragons have elevated levels of the Nitrogen-15 isotope in their blood suggesting that a city diet, which incorporates novel anthropogenic food sources, may also be richer in protein. These results highlight the role that gut microbial plasticity plays in an animals' response to human-altered landscapes.

RevDate: 2019-10-08

Balázs J, Rózsa Z, Bereczki Z, et al (2019)

Osteoarcheological and biomolecular evidence of leprosy from an 11-13th century CE Muslim cemetery in Europe (Orosháza, Southeast Hungary).

Homo : internationale Zeitschrift fur die vergleichende Forschung am Menschen, 70(2):105-118.

Orosháza site no. 10 (Southeast Hungary) contains the partially excavated archaeological remains of an 11-13th century CE Muslim merchant village and its cemetery located in close proximity to Christian villages of the same era. The skeleton of a young woman (grave no. 16) from the last phase of the cemetery use was identified with rhinomaxillary lesions associated with lepromatous leprosy. The right parietal bone also exhibited signs of cranial trauma, possibly caused by symbolic trepanation, a well-known ritual practice in the 9-11th century CE Carpathian Basin. The retrospective diagnosis of the disease was supported by ancient DNA analysis, as the samples were positive for Mycobacterium leprae aDNA, shown to be of genotype 3. Contrary to the general practice of the era, the body of the young female with severe signs of leprosy was interred among the regular graves of the Muslim cemetery in Orosháza, which may reflect the unique cultural background of the community.

RevDate: 2019-10-08

Gilbert E, O'Reilly S, Merrigan M, et al (2019)

The genetic landscape of Scotland and the Isles.

Proceedings of the National Academy of Sciences of the United States of America, 116(38):19064-19070.

Britain and Ireland are known to show population genetic structure; however, large swathes of Scotland, in particular, have yet to be described. Delineating the structure and ancestry of these populations will allow variant discovery efforts to focus efficiently on areas not represented in existing cohorts. Thus, we assembled genotype data for 2,554 individuals from across the entire archipelago with geographically restricted ancestry, and performed population structure analyses and comparisons to ancient DNA. Extensive geographic structuring is revealed, from broad scales such as a NE to SW divide in mainland Scotland, through to the finest scale observed to date: across 3 km in the Northern Isles. Many genetic boundaries are consistent with Dark Age kingdoms of Gaels, Picts, Britons, and Norse. Populations in the Hebrides, the Highlands, Argyll, Donegal, and the Isle of Man show characteristics of isolation. We document a pole of Norwegian ancestry in the north of the archipelago (reaching 23 to 28% in Shetland) which complements previously described poles of Germanic ancestry in the east, and "Celtic" to the west. This modern genetic structure suggests a northwestern British or Irish source population for the ancient Gaels that contributed to the founding of Iceland. As rarer variants, often with larger effect sizes, become the focus of complex trait genetics, more diverse rural cohorts may be required to optimize discoveries in British and Irish populations and their considerable global diaspora.

RevDate: 2019-10-02

Gower G, Fenderson LE, Salis AT, et al (2019)

Widespread male sex bias in mammal fossil and museum collections.

Proceedings of the National Academy of Sciences of the United States of America, 116(38):19019-19024.

A recent study of mammoth subfossil remains has demonstrated the potential of using relatively low-coverage high-throughput DNA sequencing to genetically sex specimens, revealing a strong male-biased sex ratio [P. Pečnerová et al., Curr. Biol. 27, 3505-3510.e3 (2017)]. Similar patterns were predicted for steppe bison, based on their analogous female herd-based structure. We genetically sexed subfossil remains of 186 Holarctic bison (Bison spp.), and also 91 brown bears (Ursus arctos), which are not female herd-based, and found that ∼75% of both groups were male, very close to the ratio observed in mammoths (72%). This large deviation from a 1:1 ratio was unexpected, but we found no evidence for sex differences with respect to DNA preservation, sample age, material type, or overall spatial distribution. We further examined ratios of male and female specimens from 4 large museum mammal collections and found a strong male bias, observable in almost all mammalian orders. We suggest that, in mammals at least, 1) wider male geographic ranges can lead to considerably increased chances of detection in fossil studies, and 2) sexual dimorphic behavior or appearance can facilitate a considerable sex bias in fossil and modern collections, on a previously unacknowledged scale. This finding has major implications for a wide range of studies of fossil and museum material.

RevDate: 2020-01-27

Hermes TR, Frachetti MD, Doumani Dupuy PN, et al (2019)

Early integration of pastoralism and millet cultivation in Bronze Age Eurasia.

Proceedings. Biological sciences, 286(1910):20191273.

Mobile pastoralists are thought to have facilitated the first trans-Eurasian dispersals of domesticated plants during the Early Bronze Age (ca 2500-2300 BC). Problematically, the earliest seeds of wheat, barley and millet in Inner Asia were recovered from human mortuary contexts and do not inform on local cultivation or subsistence use, while contemporaneous evidence for the use and management of domesticated livestock in the region remains ambiguous. We analysed mitochondrial DNA and multi-stable isotopic ratios (δ13C, δ15N and δ18O) of faunal remains from key pastoralist sites in the Dzhungar Mountains of southeastern Kazakhstan. At ca 2700 BC, Near Eastern domesticated sheep and goat were present at the settlement of Dali, which were also winter foddered with the region's earliest cultivated millet spreading from its centre of domestication in northern China. In the following centuries, millet cultivation and caprine management became increasingly intertwined at the nearby site of Begash. Cattle, on the other hand, received low levels of millet fodder at the sites for millennia. By primarily examining livestock dietary intake, this study reveals that the initial transmission of millet across the mountains of Inner Asia coincided with a substantial connection between pastoralism and plant cultivation, suggesting that pastoralist livestock herding was integral for the westward dispersal of millet from farming societies in China.

RevDate: 2019-09-01

Oosting T, Star B, Barrett JH, et al (2019)

Unlocking the potential of ancient fish DNA in the genomic era.

Evolutionary applications, 12(8):1513-1522 pii:EVA12811.

Fish are the most diverse group of vertebrates, fulfil important ecological functions and are of significant economic interest for aquaculture and wild fisheries. Advances in DNA extraction methods, sequencing technologies and bioinformatic applications have advanced genomic research for nonmodel organisms, allowing the field of fish ancient DNA (aDNA) to move into the genomics era. This move is enabling researchers to investigate a multitude of new questions in evolutionary ecology that could not, until now, be addressed. In many cases, these new fields of research have relevance to evolutionary applications, such as the sustainable management of fisheries resources and the conservation of aquatic animals. Here, we focus on the application of fish aDNA to (a) highlight new research questions, (b) outline methodological advances and current challenges, (c) discuss how our understanding of fish ecology and evolution can benefit from aDNA applications and (d) provide a future perspective on how the field will help answer key questions in conservation and management. We conclude that the power of fish aDNA will be unlocked through the application of continually improving genomic resources and methods to well-chosen taxonomic groups represented by well-dated archaeological samples that can provide temporally and/or spatially extensive data sets.

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RJR Experience and Expertise

Researcher

Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.

Educator

Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.

Administrator

Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.

Technologist

Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.

Publisher

While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.

Speaker

Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.

Facilitator

Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.

Designer

Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

short personal version

Curriculum Vitae for R J Robbins

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RJR Picks from Around the Web (updated 11 MAY 2018 )