Animal Diseases Leapt To Humans When We Started Keeping Livestock

Researchers analyzing DNA from 1,313 ancient humans across Eurasia found that zoonotic pathogens first appeared in human populations around 6,500 years ago, coinciding with the transition from hunter-gatherer societies to livestock farming.

The genomic study, published in Nature, identified 5,486 DNA sequences from bacteria, viruses and parasites in blood remnants from bones and teeth spanning 37,000 years. Zoonotic pathogens were detected only in remains 6,500 years old or younger, peaking around 5,000 years ago when pastoralist communities from the Steppe region migrated into Europe with large herds. The plague bacterium Yersinia pestis first appears in the dataset between 5,700-5,300 years ago.