Cattle demographic history modelled from autosomal sequence variation

Area of Science:

• Genetics
• Evolutionary Biology
• Animal Science

Background:

• Phylogeography of cattle genetic variants is well-described, informing domestication history.
• Demographic models inferred from cattle genetic data are scarce.

Purpose of the Study:

• To infer demographic models from sequence diversity data in cattle populations.
• To investigate distinct population histories of Bos indicus and Bos taurus.

Main Methods:

• Sequencing 37,000 bp from 17 genes in African, European, and Indian cattle.
• Comparing unfolded site frequency spectra to simulated data using diffusion approximation.
• Building a best-fitting demographic model for past population changes.

Main Results:

• Bos indicus exhibits higher diversity statistics compared to Bos taurus.
• Bos taurus ancestry suggests an earlier, glaciation-induced population bottleneck.
• Bos indicus demography indicates a later, domestication-associated constriction and significant secondary admixture from South Asian aurochs.

Conclusions:

• Cattle populations, Bos indicus and Bos taurus, possess distinct demographic histories.
• The domestication of Bos indicus was complex, likely involving multiple events and introgression from wild aurochs.
• Archaeological evidence supports the plausibility of introgression from wild oxen into domestic herds in South Asia.