Human domestication of the prehistoric wild aurochs, Bos primigenius (pictured below), is considered one of the most important milestones in the rise of modern human culture. Dated to approximately 10,000 years before present, the first domesticated cattle represent humans' early foray into the realm of keeping livestock over hunting and gathering--in time, the stability afforded by this and other agricultural practices would allow for the establishment of cities and towns.
A new analysis of ancient DNA from a 6,750-year-old British wild aurochs offers insight to the early days of domestic cattle's divergence from the aurochs. The two living species of domestic bovines--cattle (Bos taurus) and zebu (Bos indicus)--were domesticated respectively in the Middle East and South Asia from populations of Bos primigenius, but did early cattle and contemporaneous wild aurochs continue to interbreed? The ancient genome analysis suggests that by and large the answer is no, as most living breeds of cattle show little evidence of mtDNA similarity with the aurochs and nuclear DNA likewise suggests minimal admixture. However, the aurochs genome shows similarity and significant evidence of gene flow with traditional Irish and British cattle breeds such as the Highland, Kerry, Dexter, Welsh Black, and White Park. So while sampled modern African, Asian, Middle Eastern, and mainland European cattle show minimal evidence of inward gene flow from prehistoric aurochs, breeds endemic to the British Isles stand anomalous. The researchers suggest this may be evidence of early British herders purposefully restocking with indigenous wild aurochs, or at least that cattle-aurochs hybrids survived and produced lineages contributing to modern-day populations. The study provides a fascinating look at the earliest days of one of humanity's most pervasive modern behaviors and widespread cultural phenomena, and paves the way for future analyses of anthropogenic artificial selection colliding with the natural world.