Ancient DNA Reveals 11,000-Year-Old Bond Between Humans and Sheep
An international team of researchers has analyzed 118 ancient sheep genomes, uncovering the deep-rooted relationship between humans and sheep that spans over 11,000 years.
This study, led by geneticists from Trinity College Dublin and zooarchaeologists from LMU Munich and the Bavarian State Collections of Natural History, provides insights into the domestication and selective breeding practices that have shaped sheep populations across Eurasia.
Key Findings:
Origins of Domestication: Genomic analysis of sheep bones from Aşıklı Höyük, an early herding village in central Türkiye, indicates that wild mouflon were domesticated in the western part of the northern Fertile Crescent over 11,000 years ago.
Early Selective Breeding: By 8,000 years ago, evidence shows that farmers were intentionally selecting sheep for specific traits, such as coat color. The study identified selection near the "KIT" gene, associated with white coat color in various livestock, marking the earliest known instance of deliberate genetic selection in sheep.
Genetic Divergence and Migration: Early domestic sheep populations in Europe and regions like Iran and Central Asia had distinct genetic lineages. However, subsequent human migrations facilitated the movement of sheep from eastern populations to the west. Notably, around 5,000 years ago, pastoralist societies from the Eurasian steppes expanded westward, bringing their sheep herding practices with them. This migration not only transformed human populations but also introduced new sheep ancestries into Europe.
Implications:
The findings highlight the intertwined evolution of human societies and sheep, demonstrating how migrations and cultural exchanges have influenced the genetic makeup of domestic animals. Dr. Kevin Daly, the study's first author, noted, "One of our most striking discoveries was a major prehistoric sheep migration from the Eurasian steppes into Europe during the Bronze Age. This parallels what we know about human migrations during the same period, suggesting that when people moved, they brought their flocks with them."
Professor Dan Bradley, the research leader, added, "This research demonstrates how the relationship between humans and sheep has evolved over millennia. From the early days of domestication through to the development of wool as a crucial textile resource, sheep have played a vital role in human cultural and economic development."
This comprehensive genomic study sheds light on the complex history of sheep domestication and the significant role these animals have played in shaping human civilization.