Biology subjects

Valdiosera, C.

Publications and source records attributed to Valdiosera, C..

6 recordsLinked to original sources

bioRxiv2026

Seven Millennia of Human Exploitation drove genomic Changes in Iberian Sheep

As one of the first domestic livestock species, sheep have played a fundamental role in human societies since the Neolithic. However, their demographic history remains poorly understood. To shed light on the demographic dynamics of sheep at the western edge of the Mediterranean, we sequenced 22 ancient sheep genomes from Iberia (dating from 7, 270 to 1, 615 calBP, sequenced up to 8.74 x coverage) along with one modern European mouflon from Corsica. We provide evidence for an initial maritime introduction into Iberia, and show that European mouflons are descendants of feralized Neolithic sheep. Further-more, we identify a secondary influx of "Eastern" genetic ancestry coinciding with the arrival of human Steppe ancestry in Iberia - an event that likely aligns with the spread of woolly sheep across Europe. A third population expansion is observed during the Roman period, a time when historical sources reference the trade of fine-wool sheep. This Roman-era expansion appears to have significantly influenced the genetic makeup of modern European sheep, contributing to the development of popular modern-day breeds such as Merino. In addition to these major events, we see indications of additional, minor episodes of prehistoric gene flow into the Iberian population, suggesting that western European sheep experienced more dynamic demographic changes than other domestic animals, humans, or sheep populations elsewhere. Together, these results highlight the dynamic history of Iberian sheep populations and demonstrate how human cultural and demographic shifts have left their hoofprints in the sheep gene pool, marking them as a valuable proxy for understanding the human past.

evolutionary biology↗

bioRxiv2023

The Genomic Legacy of Human Management and sex-biased Aurochs hybridization in Iberian Cattle

Cattle have been a valuable economic resource and cultural icon since prehistory. From the initial expansion of domestic cattle into Europe during the Neolithic period, taurine cattle (Bos taurus) and their wild ancestor, the aurochs (B. primigenius), had overlapping ranges, leading to ample opportunities for mating (whether intended by farmers or not). We performed a bioarchaeological analysis of 24 Bos remains from Iberia dating from the Mesolithic to the Roman period. The archaeogenomic dataset allows us to investigate the extent of domestic-wild hybridization over time, providing insight into the species behavior and human hunting and management practices by aligning changes with cultural and genomic transitions in the archaeological record. Our results show frequent hybridization during the Neolithic and Chalcolithic, likely reflecting a mix of hunting and herding or relatively unmanaged herds, with mostly male aurochs and female domestic cattle involved in hybridization. This is supported by isotopic evidence consistent with ecological niche sharing, with only a few domestic cattle possibly being managed. The proportion of aurochs ancestry remains relatively constant from about 4000 years ago, probably due to herd management and selection against first generation hybrids, coinciding with other cultural transitions. The constant level of wild ancestry ({bsim}20%) continues into modern western European breeds including the Spanish Lidia breed which is bred for its aggressiveness and fighting ability, but does not display elevated levels of aurochs ancestry. This study takes a genomic glance at the impact of human actions and wild introgression in the establishment of cattle as one of the most important domestic species today.

genomics↗

bioRxiv2022

Demographic history and genetic structure in pre-Hispanic Central Mexico

Aridoamerica and Mesoamerica are two distinct cultural areas that hosted numerous pre-Hispanic civilizations between 2,500 BCE and 1,521 CE. The division between these regions shifted southward due to severe droughts ca. 1,100 years ago, allegedly driving demographic changes and population replacement in some sites in central Mexico. Here, we present shotgun genome-wide data from 12 individuals and 26 mitochondrial genomes from eight pre-Hispanic archaeological sites across Mexico, including two at the shifting border of Aridoamerica and Mesoamerica. We find population continuity spanning the climate change episode and a broad preservation of the genetic structure across present-day Mexico for the last 2,300 years. Lastly, we identify a contribution to pre-Hispanic populations of northern and central Mexico from an ancient unsampled ghost population.

genomics↗

bioRxiv2020

Bioarchaeological analysis of one of the earliest Islamic burials in the Levant

The Middle East plays a central role in human history harbouring a vast diversity of ethnic, cultural and religious groups. However, much remains to be understood about past and present genomic diversity in this region. Here, we present for the first time, a multidisciplinary bioarchaeological analysis of two individuals dated to late 7th and early 8th centuries from Tell Qarassa, an open-air site in modern-day Syria. Radiocarbon dates, religious and cultural burial evidence indicate that this site represents one of the earliest Islamic Arab burials in the Levant during the Late Antiquity period. Interestingly, we found genomic similarity to a genotyped group of modern-day Bedouins and Saudi rather than to most neighbouring Levantine groups. This is highlighted through substantial Neolithic Levant ancestry in our samples, inviting an alternative scenario of long-term continuity in this region. This raises questions about the influence of ancient populations and historical migrations to genetic structure in the Middle East. As our study represents the first genomic analysis of an early Islamic burial in the Levant, we discuss our findings and possible historic scenarios in light of forces such as genetic drift and their possible interaction with religious and cultural processes.

genetics↗

bioRxiv2017

Genomics of Mesolithic Scandinavia reveal colonization routes and high-latitude adaptation

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the last glaciation. However, the origin(s) of the first colonizers and their migration routes remain unclear. We sequenced the genomes, up to 57x coverage, of seven hunter-gatherers excavated across Scandinavia and dated to 9,500-6,000 years before present. Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. This result suggests that Scandinavia was initially colonized following two different routes: one from the south, the other from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These adaptations include high frequencies of low pigmentation variants and a gene-region associated with physical performance, which shows strong continuity into modern-day northern Europeans.

genomics↗

bioRxiv2016

Ancient individuals from the North American Northwest Coast reveal 10,000 years of regional genetic continuity

Recent genome-wide studies of both ancient and modern indigenous people of the Americas have shed light on the demographic processes involved during the first peopling. The Pacific northwest coast proves an intriguing focus for these studies due to its association with coastal migration models and genetic ancestral patterns that are difficult to reconcile with modern DNA alone. Here we report the genome-wide sequence of an ancient individual known as \"Shuka Kaa\" (\"Man Ahead of Us\") recovered from the On Your Knees Cave (OYKC) in southeastern Alaska (archaeological site 49-PET-408). The human remains date to approximately 10,300 cal years before present (BP). We also analyze low coverage genomes of three more recent individuals from the nearby coast of British Columbia dating from approximately 6075 to 1750 cal years BP. From the resulting time series of genetic data, we show that the Pacific Northwest Coast exhibits genetic continuity for at least the past 10,300 cal BP. We also infer that population structure existed in the late Pleistocene of North America with Shuka Kaa on a different ancestral line compared to other North American individuals (i.e., Anzick-1 and Kennewick Man) from the late Pleistocene or early Holocene. Despite regional shifts in mitochondrial DNA haplogroups we conclude from individuals sampled through time that people of the northern Northwest Coast belong to an early genetic lineage that may stem from a late Pleistocene coastal migration into the Americas.\n\nSignificance StatementThe peopling of the Americas has been examined on the continental level with the aid of single-nucleotide polymorphism arrays, next generation sequencing, and advancements in ancient DNA, all of which have helped elucidate major population movements. Regional paleogenomic studies, however, have received less attention and may reveal a more nuanced demographic history. Here we present genomewide sequences of individuals from the northern Northwest Coast covering a time span of ~10,000 years and show that continental patterns of demography do not necessarily apply on the regional level. In comparison with existing paleogenomic data, we demonstrate that geographically linked population samples from the Northwest Coast exhibit an early ancestral lineage and find that population structure existed among Native North American groups as early as the late Pleistocene.

genomics↗