Sheep in arid landscape, southeastern Morocco.
Photo by J. Peters, LMU_SNSB
Domesticated animals are an embarrassment for creationists who believe that their god created all the animals for the convenience of mankind, because just about every domesticated animal (or plant for that matter) has been highly modified by selective breeding to make it suitable for whatever purpose it was domesticated for.
An intelligent god could have made them fit for purpose in the first place, if it had really created them for mankind's convenience. This shows that either the creation myth is wrong, or the creator god lacked the foresight to know what humans would be using the animals for. So, we've had to modify them, in some cases. almost beyond recognition as the descendants of their wild ancestors, to make them fit for purpose.
And it gets worse when we discover that the domestication process began long before the same creation myth says all the animals were created in the same week as humans.
Sheep, for example, according to a study by an international and interdisciplinary team of researchers led by geneticists from Trinity College Dublin, and zooarchaeologists from Ludwig Maximilian University Munich and the Bavarian State Collections of Natural History (SNSB) were first domesticated over 11,000 years ago. An analysis of their genome also reflects patterns of migration in the human population, with whom sheep have been intertwined for over 11,000 years.
Tell me all about the origins and domestication of modern breeds of sheep, please. The origins and domestication of modern sheep (Ovis aries) trace back to the early Neolithic period, around 10,000–11,000 years ago, in the Fertile Crescent—an area covering parts of modern-day Turkey, Iran, Iraq, and Syria. Sheep were among the first animals domesticated by humans, following the domestication of dogs and coinciding with early agriculture.Their research is published in Science and explained in a Trinity College News item:
Wild Ancestors and Early Domestication
The primary ancestor of domestic sheep is the mouflon (Ovis orientalis), specifically the Anatolian and Iranian subspecies (Ovis orientalis gmelini). Mouflons are small, hardy sheep with short, coarse hair rather than wool. Early domesticated sheep were likely kept for their meat, milk, and hides, rather than wool, which only became an important trait later in their domestication.
Domestication Process
Early Neolithic herders selectively bred sheep for docility, size, and productivity. Over time, domestic sheep developed significant differences from their wild ancestors:By 6,000–5,000 BCE, domesticated sheep had spread throughout Europe, North Africa, and parts of Asia.
- Increased body size for better meat yield.
- Loss of aggression and wariness, making them easier to manage.
- Wool production, which emerged around 6,000 years ago through selective breeding, replacing the original hairy coat.
- Tail fat storage, which developed in some breeds, particularly in the Middle East and North Africa.
Spread and Breed Diversification
As sheep were taken to different regions, they adapted to local climates and human needs, leading to a wide variety of breeds. The breeding of sheep for specialized traits, such as fine wool, meat quality, or dairy production, became more refined over millennia.
Key Developments in Sheep BreedsModern Sheep Breeds
- Wool-bearing sheep (~4,000 BCE): Evidence from Mesopotamian art suggests the existence of woolly sheep. Wool became a major resource for textiles.
- Roman Influence (~500 BCE–400 CE): The Romans introduced selective breeding across their empire, spreading advanced sheep breeds across Europe.
- Medieval and Renaissance Periods: The Spanish Merino breed (developed in the Middle Ages) became prized for its exceptionally fine wool, driving the European wool trade.
- 17th-19th Century Breed Development: The Industrial Revolution further refined sheep breeds, with a focus on meat, milk, and wool production. British breeds such as Leicester Longwool and Southdown were developed during this period.
Today, there are over 1,000 recognized sheep breeds, classified based on their primary use:
Sheep in Agriculture Today
- Wool breeds: Merino, Rambouillet, Lincoln
- Meat breeds: Suffolk, Texel, Dorset
- Dairy breeds: East Friesian, Lacaune
- Dual-purpose breeds: Romney, Corriedale
Sheep farming remains crucial worldwide, particularly in Australia, New Zealand, China, and the UK, where large-scale wool and meat industries thrive. Selective breeding continues to improve productivity, resilience, and disease resistance.
Genetics of Sheep Domestication
The domestication of sheep (Ovis aries) involved complex genetic changes driven by natural selection, human intervention, and environmental pressures. Advances in genomic studies have provided insights into the genetic markers that distinguish domestic sheep from their wild ancestors, particularly in traits like wool growth, tameness, and productivity.
- Domestication Bottlenecks and Genetic Diversity
Domesticated sheep descended from wild mouflon (Ovis orientalis), primarily from populations in Anatolia and Iran. Genetic studies suggest that domestication involved multiple independent events rather than a single domestication event.
- Genetic Bottlenecks: The transition from wild to domestic sheep resulted in a loss of genetic diversity, as only certain individuals with desirable traits were selected for breeding.
- Mitochondrial DNA (mtDNA): Analysis of mtDNA has identified five major maternal haplogroups in modern sheep, indicating multiple domestication lineages. These haplogroups are labelled A, B, C, D, and E, with haplogroup A being the most widespread.
- Key Genetic Changes in Domesticated Sheep
Through selective breeding, early herders promoted specific traits, many of which have been linked to particular genes.
A. Wool Development
One of the most significant genetic changes in sheep is the transition from a coarse, hair-like coat to a woolly fleece. This shift is associated with:
- FGF5 (Fibroblast Growth Factor 5) gene: Mutations in FGF5 promote continuous wool growth by disrupting the natural shedding cycle.
- KRT and KAP genes (Keratin and Keratin-Associated Proteins): These genes influence wool fibre structure and quality.
B. Coat Color and Patterning
- MC1R (Melanocortin 1 Receptor) and ASIP (Agouti Signalling Protein) genes:
These regulate pigmentation in sheep. Wild mouflon have a reddish-brown coat, while domestication introduced a variety of colours, including white, black, and spotted patterns.- TYRP1 and MITF genes: Also involved in coat color variation.
C. Tameness and Behavioural Traits
Like other domesticated animals, sheep exhibit genetic modifications affecting social behaviour and docility.
D. Meat and Milk Production
- Oxytocin receptor (OXTR) gene: Plays a role in social bonding and herd behaviour.
- DRD4 (Dopamine Receptor D4) gene: Involved in temperament, influencing docility and response to human handling.
E. Fat Deposition and Adaptation
- GDF8 (Myostatin) gene: Controls muscle growth. Mutations in this gene have led to heavily muscled breeds like the Texel.
- CSN1S1 and CSN3 (Casein) genes: Influence milk protein composition, particularly in dairy breeds like the East Friesian.
- ADIPOQ (Adiponectin) gene: Regulates fat metabolism and is linked to the development of fat-tailed sheep, which store fat reserves in their tails to survive in harsh environments.
- PRLR (Prolactin Receptor) gene: Involved in seasonal breeding and adaptation to different climates.
Hybridization and Introgression
- Genomic studies show evidence of gene flow between wild and domestic sheep in certain regions.
- Introgression from Argali sheep (Ovis ammon) has been detected in some Central Asian sheep breeds, possibly influencing size and robustness.
Ongoing Genetic Research
- Genome-Wide Association Studies (GWAS) are identifying new genes linked to disease resistance, fertility, and climate resilience.
- CRISPR and Gene Editing: Scientists are exploring ways to enhance wool quality, disease resistance, and productivity through genetic engineering.
Ancient DNA analyses bring to life the 11,000-year intertwined genomic history of sheep and humans
As early as 8,000 years ago the team found evidence that farmers were deliberately selecting their flocks – for example, for the genes coding for coat colour.
Sheep have been intertwined with human livelihoods for over 11,000 years. As well as meat, their domestication led to humans being nourished by their protein-rich milk and clothed by warm, water-resistant fabrics made from their wool.
Now, an international and interdisciplinary team of researchers led by geneticists from Trinity and zooarchaeologists from LMU Munich and the Bavarian State Collections of Natural History (SNSB) has deciphered the prehistoric cultural trajectory of this species by analysing 118 genomes recovered from archaeological bones dating across 12 millennia and stretching from Mongolia to Ireland.
The earliest sheep-herding village in the sample, Aşıklı Höyük in central Türkiye, has genomes that seem ancestral to later populations in the wider region, confirming an origin in captures of wild mouflon over 11,000 years ago in the western part of the northern Fertile Crescent.
Sheep in arid landscape, southeastern Morocco.Photo by J. Peters, LMU_SNSB
By 8,000 years ago, in the earliest European sheep populations, the team found evidence that farmers were deliberately selecting their flocks – in particular for the genes coding for coat colour.
Along with a similar signal in goats, this is the earliest evidence for human moulding of another animal’s biology and shows that early herders, like today’s farmers, were interested in the beautiful and unusual in their animals.
Specifically, the main gene the team found evidence of selection near was one known as “KIT”, which is associated with white coat colour in a range of livestock.
Also by that time, the earliest domestic sheep genomes from Europe and further east in Iran and Central Asia had diverged from each other. However, this separation did not last as people translocated sheep from eastern populations to the west.
First, in parallel with human cultural influences spreading out from the early cities of Mesopotamia we see sheep genomes moving west within the Fertile Crescent around 7,000 years ago.
Second, the rise of pastoralist peoples in the Eurasian steppes and their westward spread some 5,000 years ago profoundly transformed ancestral European human populations and their culture. This process changed the makeup of human populations, for example, altering the ancestry of British peoples by around 90%, and introduced the Indo-European language ancestor of the tongues spoken across the continent today.
From the dataset used in this study it now seems that this massive migration was fuelled by sheep herding and exploitation of lifetime products, including milk and probably cheese, as it is around the same time that sheep ancestries are also changed. Consequently, by the Bronze Age, herds had about half their ancestry from a source in the Eurasian steppe.
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.
Assistant Professor Dr Kevin Daly, first author School of Agriculture and Food Science, University College, Dublin, Ireland.
Today's descendants of the first domestic sheep of Central Anatolia.Photo N. Pollath, SNSB.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.
Professor Daniel G. Bradley, co-author
Professor of Population Genetics
School of Genetics and Microbiology
Trinity College, Dublin, Ireland.Our study, while convincingly reconciling morphological and genomic evidence of the geographic origin of domestic sheep, clearly illustrates that further transdisciplinary research is needed to clarify the patterns of dispersal and selection of the many landraces occurring today in Eurasia and Africa.
Professor Joris Peters, co-corresponding author
Professor of Paleoanatomy
Domestication Research and the History of Veterinary Medicine
Ludwig Maximilian University Munich
Director of the State Collection for Paleoanatomy Munich (SNSB-SPM).
Scottish Blackface from Applecross, Scotland - a common sheep breed of the British Isles. This breed is represented in the panel of modern reference genomes.Photo by J. Peters
Publication:Kevin G. Daly et al.
Ancient genomics and the origin, dispersal, and development of domestic sheep
Science 387, 492-497 (2025). DOI:10.1126/science.adn2094
AbstractWhat that means is that centres of sheep breeding arose in Europe and Central Asia and elsewhere, then, along with the influx of Humans from the Asian Steppe into western Europe, there was an influx of sheep from the Asian Steppe, showing that the migrants brought their sheep with them, so the genetic signatures of these migrations of humans and sheep map onto one another.
The origins and prehistory of domestic sheep (Ovis aries) are incompletely understood; to address this, we generated data from 118 ancient genomes spanning 12,000 years sampled from across Eurasia. Genomes from Central Türkiye ~8000 BCE are genetically proximal to the domestic origins of sheep but do not fully explain the ancestry of later populations, suggesting a mosaic of wild ancestries. Genomic signatures indicate selection by ancient herders for pigmentation patterns, hornedness, and growth rate. Although the first European sheep flocks derive from Türkiye, in a notable parallel with ancient human genome discoveries, we detected a major influx of Western steppe–related ancestry in the Bronze Age.
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