Dog domestication, from the fierce to the feisty

The relationship between humans and animals is as old as humanity itself. Dogs are believed to be the first animals domesticated by humans, and much of the wide physical variation that exists in dogs today is thought to result from this long-term relationship. The prevailing narrative is that early dogs were not as diverse as modern dogs and that the diversity of modern dogs resulted from intensive breeding programs in the Victorian era (mid– to late 19th century) that led to the selection of traits such as large round eyes, shortened snouts, and floppy ears. On page 741 of this issue, Evin et al. (1) report that dog populations were already diverse millennia before modern breeding programs.