The emergence of pastoralist communities in the Eurasian steppes, along with their movement westward approximately 5,000 years ago, might have been driven by the practice of sheep herding and the utilization of sheep milk. Evidence indicates that as early as 8,000 years ago, farmers were purposefully selecting their sheep based on traits such as coat color. Over the past 11,000 years, sheep have been an essential part of human life, providing not just meat but also protein-rich milk and warm, water-resistant wool for clothing. Recently, a group of geneticists has explored the ancient cultural history of sheep by studying 118 genomes from archaeological bones, spanning 12,000 years and locations from Mongolia to Ireland.
For over 11,000 years, sheep have been crucial to human life, offering meat, nourishing milk, and warm, water-resistant wool for clothing.
A diverse team of researchers, headed by geneticists at Trinity College Dublin alongside zooarchaeologists from LMU Munich and the Bavarian State Collections of Natural History (SNSB), has examined how sheep have influenced human civilization over millennia by analyzing 118 genomes retrieved from archaeological sites across a 12,000-year period, extending from Mongolia to Ireland.
The earliest evidence of a sheep-herding settlement in their study comes from Aşıklı Höyük in central Turkey. The genomes discovered there appear to be ancestors of later populations in the surrounding area, indicating that these sheep originated from the hunting of wild mouflon over 11,000 years ago in the northern Fertile Crescent.
By around 8,000 years ago, the earliest sheep populations in Europe showed signs that farmers were intentionally selecting sheep for specific traits, particularly those linked to coat color. This is the first evidence of humans actively influencing the biology of another animal, similar to what is observed today with agriculture, highlighting early herders’ interests in unique and aesthetically pleasing animals.
The primary gene identified as being selectively bred is called “KIT,” which is associated with the white coat color found in various livestock.
During this time, early domestic sheep from Europe, Iran, and Central Asia began to show distinct genetic differences. However, this separation was temporary, as sheep were moved from eastern to western populations.
Initially, around 7,000 years ago, sheep genomes began migrating westward alongside cultural influences from the early cities of Mesopotamia.
Subsequently, the rise of pastoralist groups in the Eurasian steppes and their westward movement around 5,000 years ago significantly impacted the genetic makeup and cultural practices of ancient European populations. This transformation altered the ancestry of British populations by roughly 90% and led to the introduction of the Indo-European language ancestors, which contribute to the modern languages spoken across Europe.
Analysis of the data from this research suggests that the large-scale migration was largely driven by the practice of sheep herding and the use of sheep products such as milk and likely cheese. This period corresponds with notable changes in sheep ancestry. By the Bronze Age, sheep herds had gained about half of their genetic lineage from populations in the Eurasian steppes.
According to Dr. Kevin Daly, Ad Astra Assistant Professor at UCD School of Agriculture and Food Science and an Adjunct Assistant Professor at Trinity’s School of Genetics and Microbiology, who is the lead author of the recently published research in the prestigious journal Science, “Our findings highlight a significant prehistoric migration of sheep from the Eurasian steppes into Europe during the Bronze Age, illustrating how human migrations often involved relocating livestock.”
Dan Bradley, head of the research and a Professor of Population Genetics at Trinity’s School of Genetics and Microbiology, stated, “This study reveals the evolving relationship between humans and sheep over thousands of years. From their early domestication to the importance of wool as a vital textile resource, sheep have been integral to human cultural and economic advancement.”
Joris Peters, co-corresponding author and Professor of Paleoanatomy, Domestication Research, and the History of Veterinary Medicine at LMU Munich, emphasized that “while our study provides a compelling integration of morphological and genomic data regarding the origins of domestic sheep, it also highlights the need for further interdisciplinary research to better understand the distribution and selection processes of the various sheep breeds that exist today in Eurasia and Africa.”
