As the Turkish government intensified its attacks on the theory of evolution, the academic community rallied to push back. A researcher recounts how she decided to join them.
Analysis of microbial data from archaeological samples is a growing field with great potential for understanding ancient environments, lifestyles, and diseases. However, high error rates have been a ...challenge in ancient metagenomics, and the availability of computational frameworks that meet the demands of the field is limited. Here, we propose aMeta, an accurate metagenomic profiling workflow for ancient DNA designed to minimize the amount of false discoveries and computer memory requirements. Using simulated data, we benchmark aMeta against a current state-of-the-art workflow and demonstrate its superiority in microbial detection and authentication, as well as substantially lower usage of computer memory.
The great ethnolinguistic diversity found today in mainland Southeast Asia (MSEA) reflects multiple migration waves of people in the past. Maritime trading between MSEA and India was established at ...the latest 300 BCE, and the formation of early states in Southeast Asia during the first millennium CE was strongly influenced by Indian culture, a cultural influence that is still prominent today. Several ancient Indian-influenced states were located in present-day Thailand, and various populations in the country are likely to be descendants of people from those states. To systematically explore Indian genetic heritage in MSEA populations, we generated genome-wide SNP data (using the Affymetrix Human Origins array) for 119 present-day individuals belonging to 10 ethnic groups from Thailand and co-analyzed them with published data using PCA, ADMIXTURE, and methods relying on f-statistics and on autosomal haplotypes. We found low levels of South Asian admixture in various MSEA populations for whom there is evidence of historical connections with the ancient Indian-influenced states but failed to find this genetic component in present-day hunter-gatherer groups and relatively isolated groups from the highlands of Northern Thailand. The results suggest that migration of Indian populations to MSEA may have been responsible for the spread of Indian culture in the region. Our results also support close genetic affinity between Kra-Dai-speaking (also known as Tai-Kadai) and Austronesian-speaking populations, which fits a linguistic hypothesis suggesting cladality of the two language families.
There is growing interest in uncovering genetic kinship patterns in past societies using low‐coverage palaeogenomes. Here, we benchmark four tools for kinship estimation with such data: lcMLkin, ...NgsRelate, KIN, and READ, which differ in their input, IBD estimation methods, and statistical approaches. We used pedigree and ancient genome sequence simulations to evaluate these tools when only a limited number (1 to 50 K, with minor allele frequency ≥0.01) of shared SNPs are available. The performance of all four tools was comparable using ≥20 K SNPs. We found that first‐degree related pairs can be accurately classified even with 1 K SNPs, with 85% F1 scores using READ and 96% using NgsRelate or lcMLkin. Distinguishing third‐degree relatives from unrelated pairs or second‐degree relatives was also possible with high accuracy (F1 > 90%) with 5 K SNPs using NgsRelate and lcMLkin, while READ and KIN showed lower success (69 and 79% respectively). Meanwhile, noise in population allele frequencies and inbreeding (first‐cousin mating) led to deviations in kinship coefficients, with different sensitivities across tools. We conclude that using multiple tools in parallel might be an effective approach to achieve robust estimates on ultra‐low‐coverage genomes.
Much of the American Arctic was first settled 5,000 years ago, by groups of people known as Palaeo-Eskimos. They were subsequently joined and largely displaced around 1,000 years ago by ancestors of ...the present-day Inuit and Yup'ik
. The genetic relationship between Palaeo-Eskimos and Native American, Inuit, Yup'ik and Aleut populations remains uncertain
. Here we present genomic data for 48 ancient individuals from Chukotka, East Siberia, the Aleutian Islands, Alaska, and the Canadian Arctic. We co-analyse these data with data from present-day Alaskan Iñupiat and West Siberian populations and published genomes. Using methods based on rare-allele and haplotype sharing, as well as established techniques
, we show that Palaeo-Eskimo-related ancestry is ubiquitous among people who speak Na-Dene and Eskimo-Aleut languages. We develop a comprehensive model for the Holocene peopling events of Chukotka and North America, and show that Na-Dene-speaking peoples, people of the Aleutian Islands, and Yup'ik and Inuit across the Arctic region all share ancestry from a single Palaeo-Eskimo-related Siberian source.
The social organization of the first fully sedentary societies that emerged during the Neolithic period in Southwest Asia remains enigmatic,1 mainly because material culture studies provide limited ...insight into this issue. However, because Neolithic Anatolian communities often buried their dead beneath domestic buildings,2 household composition and social structure can be studied through these human remains. Here, we describe genetic relatedness among co-burials associated with domestic buildings in Neolithic Anatolia using 59 ancient genomes, including 22 new genomes from Aşıklı Höyük and Çatalhöyük. We infer pedigree relationships by simultaneously analyzing multiple types of information, including autosomal and X chromosome kinship coefficients, maternal markers, and radiocarbon dating. In two early Neolithic villages dating to the 9th and 8th millennia BCE, Aşıklı Höyük and Boncuklu, we discover that siblings and parent-offspring pairings were frequent within domestic structures, which provides the first direct indication of close genetic relationships among co-burials. In contrast, in the 7th millennium BCE sites of Çatalhöyük and Barcın, where we study subadults interred within and around houses, we find close genetic relatives to be rare. Hence, genetic relatedness may not have played a major role in the choice of burial location at these latter two sites, at least for subadults. This supports the hypothesis that in Çatalhöyük,3–5 and possibly in some other Neolithic communities, domestic structures may have served as burial location for social units incorporating biologically unrelated individuals. Our results underscore the diversity of kin structures in Neolithic communities during this important phase of sociocultural development.
•Genetic kinship estimated from co-buried individuals’ genomes in Neolithic Anatolia•Close relatives are common among co-burials in Aşıklı and Boncuklu•Many unrelated infants found buried in the same building in Çatalhöyük and Barcın•Neolithic societies in Southwest Asia may have held diverse concepts of kinship
Yaka et al. use ancient genomes from Neolithic Anatolia and present evidence for diverse concepts of social kinship in Neolithic societies. In some communities, like Çatalhöyük, many genetically unrelated infants were buried together inside the same buildings, whereas in other sites, people buried together were frequently close biological kin.
The history of human inbreeding is controversial.1 In particular, how the development of sedentary and/or agricultural societies may have influenced overall inbreeding levels, relative to those of ...hunter-gatherer communities, is unclear.2–5 Here, we present an approach for reliable estimation of runs of homozygosity (ROHs) in genomes with ≥3× mean sequence coverage across >1 million SNPs and apply this to 411 ancient Eurasian genomes from the last 15,000 years.5–34 We show that the frequency of inbreeding, as measured by ROHs, has decreased over time. The strongest effect is associated with the Neolithic transition, but the trend has since continued, indicating a population size effect on inbreeding prevalence. We further show that most inbreeding in our historical sample can be attributed to small population size instead of consanguinity. Cases of high consanguinity were rare and only observed among members of farming societies in our sample. Despite the lack of evidence for common consanguinity in our ancient sample, consanguineous traditions are today prevalent in various modern-day Eurasian societies,1,35–37 suggesting that such practices may have become widespread within the last few millennia.
•A study of 411 ancient genomes shows inbreeding decreased over time•The decrease appears linked with population size increase enabled by agriculture•Extreme consanguineous matings did occur among agriculturalists but were rare
Ceballos et al. study 411 ancient genomes from west and central Eurasia to show that overall inbreeding levels have decreased over time, most likely owing to population size increases with agriculture. The sample contains highly consanguineous ancient individuals, but these are rare, and all come from agriculturalist backgrounds.
Sedimentary ancient DNA (sedaDNA) has become one of the standard applications in the field of paleogenomics in recent years. It has been used for paleoenvironmental reconstructions, detecting the ...presence of prehistoric species in the absence of macro remains and even investigating the evolutionary history of a few species. However, its application in archaeology has been limited and primarily focused on humans. This article argues that sedaDNA holds significant potential in addressing key archaeological questions concerning the origins, lifestyles, and environments of past human populations. Our aim is to facilitate the integration of sedaDNA into the standard workflows in archaeology as a transformative tool, thereby unleashing its full potential for studying the human past. Ultimately, we not only underscore the challenges inherent in the sedaDNA field but also provide a research agenda for essential enhancements needed for implementing sedaDNA into the archaeological workflow.
We present a spatiotemporal picture of human genetic diversity in Anatolia, Iran, Levant, South Caucasus, and the Aegean, a broad region that experienced the earliest Neolithic transition and the ...emergence of complex hierarchical societies. Combining 35 new ancient shotgun genomes with 382 ancient and 23 present-day published genomes, we found that genetic diversity within each region steadily increased through the Holocene. We further observed that the inferred sources of gene flow shifted in time. In the first half of the Holocene, Southwest Asian and the East Mediterranean populations homogenized among themselves. Starting with the Bronze Age, however, regional populations diverged from each other, most likely driven by gene flow from external sources, which we term “the expanding mobility model.” Interestingly, this increase in inter-regional divergence can be captured by outgroup-f3-based genetic distances, but not by the commonly used FST statistic, due to the sensitivity of FST, but not outgroup-f3, to within-population diversity. Finally, we report a temporal trend of increasing male bias in admixture events through the Holocene.
•Genetic diversity in Southwest Asia increased continuously through the Holocene•Regional populations admixed among themselves with the Neolithic•After the Bronze Age, populations diverged from each other via distant gene flow•Male-to-female bias increased over time in inter-regional human movements
Koptekin et al. use ancient genomes to infer population movements in Southwest Asia through 10,000 years, which saw the emergence of agriculture and later of complex societies with distant connections. The authors propose “the expanding mobility model,” where migration ranges increased over time, accompanied by growing male bias in movements.
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