Biology subjects

Morell Miranda, P.

Publications and source records attributed to Morell Miranda, P..

3 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

Ancient Sheep Genomes reveal four Millennia of North European Short-Tailed Sheep in the Baltic Sea region

Sheep are among the earliest domesticated livestock species, with a wide variety of breeds present today. However, it remains unclear how far back this breed diversity goes, with formal documentation only dating back a few centuries. North European short-tailed 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 [A]land, 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 North European short-tailed breeds, suggesting a substantial degree of long-term continuity of this breed 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 higher genetic diversity when compared to modern breeds, implying a loss of diversity in recent centuries associated with breed formation. Finally, we see a potential signature of an even earlier, genetically different form of sheep in Scandinavia as these samples do not represent the first sheep in Northern Europe. 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.

evolutionary biology↗

bioRxiv2023

Demographic Reconstruction of the Western Sheep Expansion from Whole-Genome sequences

As one of the earliest livestock, Sheep (Ovis aries) were domesticated in the Fertile Crescent about 12000 - 10000 years ago and have a nearly worldwide distribution today. Most of our knowledge about the timing of their expansions stems from archaeological data but it is unclear how the genetic diversity of modern sheep fits with these dates. We used whole-genome sequencing data of 63 domestic breeds and their wild relatives, the Asiatic mouflon (O. gmelini), to explore the demographic history of sheep. On the global scale, our analysis revealed geographic structuring among breeds with unidirectional recent gene flow from domestics into Asiatic mouflons. We then selected four representative breeds from Spain, Morocco, the UK and Iran to build a comprehensive demographic model of the Western sheep expansion. We inferred a single domestication event around 9000 years ago, slightly later than archaeological evidence suggests which might reflect uncertainties in the generation time used for these estimates. The westward expansion is dated to approximately 5000 years ago, later than the original Neolithic expansion of sheep and approximately matching the Secondary Product Revolution associated with woolly sheep. We see some signals of recent gene flow from an ancestral population into Southern European breeds which could reflect admixture with feral European mouflon. Furthermore, our results indicate that many breeds experienced a reduction of their effective population size during the last centuries, probably associated with modern breed development. Our study provides insights into the complex demographic history of Western Eurasian sheep, highlighting interactions between breeds and their wild counterparts.

genomics↗