Damla Kaptan’s research while affiliated with Middle East Technical University and other places

The emergence of Neolithic villages in Western Anatolia, particularly between 7000-6000 BCE, has caused debates regarding the driving forces behind this transition. While earlier hypotheses suggested demic diffusion from the Fertile Crescent, recent studies suggest more complex population dynamics. We address this question by combining material culture analyses with paleogenomic data to trace the Neolithic origins in the region. A single genome from the pre-7000 BCE period revealed a local population in Western Anatolia genetically linked to Epipaleolithic Central Anatolia, indicating continuity and adoption of farming by local hunter-gatherers. In the period 7000-6000 BCE, we found that some Neolithic populations still reflect a local genetic profile, while others show genetic affinity to Central Anatolia. This suggests significant population movement that accompanied cultural exchanges among regions, but also admixture between local populations and migrants from Central Anatolia, which we infer to have occurred at varying degrees in different settlements of Western Anatolia, with the highest rate observed in NW Anatolia. These admixed populations also appear to have migrated to the Western Aegean represented by N Greece here. However, when we compared material culture data with genetic data, we found no correlation between them. This suggests that cultural transmission might have occurred faster than genetic. Our analysis indicates that the Neolithization of the Aegean was a complex process involving genetic and cultural exchanges from Central Anatolia, along with admixture with local populations. These insights deepen our understanding of the intricate socio-cultural and genetic factors that influenced the development of Neolithic societies in the region.

Sheep was one of the first domesticated animals in Neolithic West Eurasia. The zooarchaeological record suggests that domestication first took place in Southwest Asia, although much remains unresolved about the precise location(s) and timing(s) of earliest domestication, or the post-domestication history of sheep. Here, we present 24 new partial sheep paleogenomes, including a 13,000-year-old Epipaleolithic Central Anatolian wild sheep, as well as 14 domestic sheep from Neolithic Anatolia, two from Neolithic Iran, two from Neolithic Iberia, three from Neolithic France, and one each from Late Neolithic/Bronze Age Baltic and South Russia, in addition to five present-day Central Anatolian Mouflons and two present-day Cyprian Mouflons. We find that Neolithic European, as well as domestic sheep breeds, are genetically closer to the Anatolian Epipaleolithic sheep and the present-day Anatolian and Cyprian Mouflon than to the Iranian Mouflon. This supports a Central Anatolian source for domestication, presenting strong evidence for a domestication event in SW Asia outside the Fertile Crescent, although we cannot rule out multiple domestication events also within the Neolithic Fertile Crescent. We further find evidence for multiple admixture and replacement events, including one that parallels the Pontic Steppe-related ancestry expansion in Europe, as well as a post-Bronze Age event that appears to have further spread Asia-related alleles across global sheep breeds. Our findings mark the dynamism of past domestic sheep populations in their potential for dispersal and admixture, sometimes being paralleled by their shepherds and in other cases not.

In this chapter, we investigate the genetics of two Early Chalcolithic Catalhoyuk individuals, U.18333 and U.16835, the only two burials yet recovered from the West Mound. These were two neonates buried within the same building. Using shotgun-sequenced partial genomes (0.06x and 0.02x coverage) we identify both as females. Despite being recovered from the same building, we find no close genetic kinship between them, in line with previously published kinship results from Catalhoyuk. We also find that the two West Mound neonates shared the same gene pool with Neolithic Catalhoyuk and other Central and West Anatolian Neolithic populations, and they did not carry the Caucasus-related U+201CeasternU+201D gene flow signature observed in later-coming Chalcolithic Anatolian genomes. This indicates no large-scale admixture between East and West Mound Catalhoyuk, and possibly that the post-Neolithic U+201CeasternU+201D gene flow event into Anatolia may have initiated only by the mid-6th millennium BCE.

Western Anatolia has been a crucial yet elusive element in the Neolithic expansion from the Fertile Crescent to Europe. Using 30 new palaeogenomes from Anatolia c.8000-6000 BCE we describe the early Holocene genetic landscape of Western Anatolia, suggesting population continuity since the late Upper Pleistocene. Our findings indicate that the Neolithisation of Western Anatolia in the 7th millennium BCE was a multifaceted process, characterised by the assimilation of Neolithic practices by indigenous groups and the influx of populations from the east, their admixed descendants eventually laying the foundations of Neolithic Southeast Europe. Intriguingly, the observed diversity in material culture among Aegean Early Neolithic communities correlates with their geographical distances but not their genetic differences, signifying a decoupling between cultural developments and genetic admixture processes.

Arguments have long suggested that the advent of early farming in the Near East and Anatolia was linked to a ‘Mother Goddess’ cult. However, evidence for a dominant female role in these societies has been scarce. We studied social organisation, mobility patterns and gendered practices in Neolithic Southwest Asia using 131 paleogenomes from Çatalhöyük East Mound (7100-5950 BCE), a major settlement in Central Anatolia with an uninterrupted occupation and an apparent egalitarian structure. In contrast to widespread genetic evidence for patrilocality in Neolithic Europe, the Çatalhöyük individuals revealed no indication of patrilocal mobility. Analysing genetic kin ties among individuals buried in the same house (co-burials) across 35 Çatalhöyük buildings, we identified close ties concentrated within buildings and among neighbours in Çatalhöyük’s Early period, akin to those in the preceding Pre-Pottery Neolithic in Southwest Asia. This pattern weakened over time: by the late 7th millennium BCE, subadults buried in the same building were rarely closely genetically related, despite sharing similar diets. Still, throughout the site’s occupation, genetic connections within Çatalhöyük buildings were much more frequently connected via the maternal than the paternal line. We also identified differential funerary treatment of female subadults compared to those of males, with a higher frequency of grave goods associated with females. Our results reveal how kinship practices changed while key female roles persisted over one thousand years in a large Neolithic community in western Eurasia.

Sheep are among the earliest domesticated livestock species, with a wide variety of breeds present today. However, it remains unclear how far back this diversity goes, with formal documentation only dating back a few centuries. North European short-tailed (NEST) breeds are often assumed to be among the oldest domestic sheep populations, even thought to represent relicts of the earliest sheep expansions during the Neolithic period reaching Scandinavia less than 6000 years ago. This study sequenced the genomes (up to 11.6X) of five sheep remains from the Baltic islands of Gotland and Åland, dating from Late Neolithic (∼4100 calBP) to historical times (∼1600 CE). Our findings indicate that these ancient sheep largely possessed the genetic characteristics of modern NEST breeds, suggesting a substantial degree of long-term continuity of this sheep type in the Baltic Sea region. Despite the wide temporal spread, population genetic analyses show high levels of affinity between the ancient genomes and they also exhibit relatively high genetic diversity when compared to modern NEST breeds, implying a loss of diversity in most breeds during the last centuries associated with breed formation and recent bottlenecks. Our results shed light on the development of breeds in Northern Europe specifically as well as the development of genetic diversity in sheep breeds, and their expansion from the domestication center in general.

Once widespread in their homelands, the Anatolian mouflon (Ovis gmelini anatolica) and the Cyprian mouflon (Ovis gmelini ophion) were driven to near extinction during the 20th century and are currently listed as endangered populations by the IUCN. While the exact origins of these lineages remain unclear, they have been suggested to be close relatives of domestic sheep or remnants of proto-domestic sheep. Here, we study whole genome sequences of n = 5 Anatolian mouflons and n = 10 Cyprian mouflons in terms of population history and diversity, comparing them to eight other extant sheep lineages. We find reciprocal genetic affinity between Anatolian and Cyprian mouflons and domestic sheep, higher than all other studied wild sheep genomes, including the Iranian mouflon (Ovis gmelini). Studying diversity indices, we detect a considerable load of short runs of homozygosity (ROH) blocks (<2 Mb) in both Anatolian and Cyprian mouflons, reflecting small effective population size (Ne). Meanwhile, Ne as well as mutation load estimates are lower in Cyprian compared to Anatolian mouflons, suggesting the purging of recessive deleterious variants in Cyprian sheep under a small long-term Ne, possibly attributable to founder effects, island isolation, introgression from domestic lineages, or differences in their bottleneck dynamics. Expanding our analyses to worldwide wild and feral Ovis genomes, we observe varying viability metrics among different lineages, and a limited consistency between viability metrics and IUCN conservation status. Factors such as recent inbreeding, introgression, and unique population dynamics may have contributed to the observed disparities.

Once widespread in their homelands, Anatolian mouflon (Ovis gmelini anatolica) and Cyprian mouflon (Ovis gmelini ophion) were driven to near extinction during the 20th century and are currently listed as endangered populations by the IUCN. While the exact origins of these lineages remain unclear, they have been suggested to be close relatives of domestic sheep or remnants of proto-domestic sheep groups. Here, we study whole genome sequences of n=5 Anatolian mouflons and n=10 Cyprian mouflons in terms of population history and diversity, relative to eight other extant sheep lineages. We find reciprocal genetic affinity between Anatolian and Cyprian mouflons and domestic sheep, higher than all other studied wild sheep genomes, including the Iranian mouflon (Ovis gmelini). Despite similar recent population dynamics, Anatolian and Cyprian mouflons exhibit disparate diversity levels, which can potentially be attributed to founder effects, island isolation, introgression from domestic lineages, or different bottleneck dynamics. The lower relative mutation load found in Cyprian compared to Anatolian mouflons suggests the purging of recessive deleterious variants in the former. This agrees with estimates of a long-term small effective population size in the Cyprian mouflon. Both subspecies harbor considerable numbers of runs of homozygosity (ROH) blocks <2 Mb, which reflects the effect of small population size. Expanding our analyses to worldwide wild and feral Ovis genomes, we observe varying viability metrics among different lineages, and a limited consistency between viability metrics and conservation status. Factors such as recent inbreeding, introgression, and unique population dynamics may contribute to the observed disparities.

A major challenge in zooarchaeology is to morphologically distinguish closely related species’ remains, especially using small bone fragments. Shotgun sequencing aDNA from archeological remains and comparative alignment to the candidate species’ reference genomes will only apply when reference nuclear genomes of comparable quality are available, and may still fail when coverages are low. Here, we propose an alternative method, MTaxi, that uses highly accessible mitochondrial DNA (mtDNA) to distinguish between pairs of closely related species from ancient DNA sequences. MTaxi utilises mtDNA transversion-type substitutions between pairs of candidate species, assigns reads to either species, and performs a binomial test to determine the sample taxon. We tested MTaxi on sheep/goat and horse/donkey data, between which zooarchaeological classification can be challenging in ways that epitomise our case. The method performed efficiently on simulated ancient genomes down to 0.3x mitochondrial coverage for both sheep/goat and horse/donkey, with no false positives. Trials on n=18 ancient sheep/goat samples and n=10 horse/donkey samples of known species identity also yielded 100% accuracy. Overall, MTaxi provides a straightforward approach to classify closely related species that are difficult to distinguish through zooarchaeological methods using low coverage aDNA data, especially when similar quality reference genomes are unavailable. MTaxi is freely available at https://github.com/goztag/MTaxi .

A major challenge in zooarchaeology is to morphologically distinguish closely related species’ remains, especially using small bone fragments. Shotgun sequencing aDNA from archeological remains and comparative alignment to the candidate species’ reference genomes will only apply when reference nuclear genomes of comparable quality are available, and may still fail when coverages are low. Here, we propose an alternative method, MTaxi, that uses highly accessible mitochondrial DNA (mtDNA) to distinguish between pairs of closely related species from ancient DNA sequences. MTaxi utilises mtDNA transversion-type substitutions between pairs of candidate species, assigns reads to either species, and performs a binomial test to determine the sample taxon. We tested MTaxi on sheep/goat and horse/donkey data, between which zooarchaeological classification can be challenging in ways that epitomise our case. The method performed efficiently on simulated ancient genomes down to 0.3x mitochondrial coverage for both sheep/goat and horse/donkey, with no false positives. Trials on n=18 ancient sheep/goat samples and n=10 horse/donkey samples of known species identity also yielded 100% accuracy. Overall, MTaxi provides a straightforward approach to classify closely related species that are difficult to distinguish through zooarchaeological methods using low coverage aDNA data, especially when similar quality reference genomes are unavailable. MTaxi is freely available at https://github.com/goztag/MTaxi .