Cattle, Bison, Neanderthals and You
Jerry Taylor traces human history through cattle genomes.
Taylor revealed his interspecies heritage during the annual Corps of Discovery lecture Sept. 16, 2013. He’d learned of it himself recently when he’d had his DNA genotyped: About 2.7 percent of his genetic code is estimated to be Neanderthal in origin. It shocked his wife, Kristen Taylor, who asked him, “Are you sure that decimal point is right? It’s not 27 percent?”
Taylor explained how genes do more than tell the story of natural selection (the reason why, 30,000 years after their extinction, Neanderthal DNA is still in humans). Genes can also be a guidebook for historians, showing where our ancestors originated, when they lived there and who else was in the neighborhood, romantically speaking.
In the animal sciences division, most of Taylor’s genetics work is with cattle. However, humanity has been wandering about with its domesticated cattle for 10,000 years, meaning the history of cattle contains some modern-human history.
A mystery of cattle domestication remains in northern Africa, where there’s a distinctly African group of cattle but no remnants of domestication sites like with other distinct groups in India’s Indus Valley and the Middle East’s Fertile Crescent.
Based on genotyping 134 breeds, Taylor suspects African cattle began as Middle Eastern domesticated cattle that migrated to Africa. There they interbred with wild aurochs that provided resistance to local diseases and whose genes were so strongly conserved that they eventually replaced the Middle Eastern genome.
It’s a process Taylor wants to reverse in U.S. bison, nearly all of which carry some cattle DNA fragments.
Taylor has observed two sets of hybrid parents that transmitted only bison genes to their offspring, which appear to be pure bison. He hopes to use DNA markers to breed out the cattle genes and recreate the ancestral bison genome.