![Gene mutation that helps make 'toy' dog breeds so small existed in wolves 54,000 years ago](https://ic-cdn.flipboard.com/futurecdn.net/9fa8a549ff709859ea8ea5cd50589d889e433862/_large.jpeg)
It existed long before humans started breeding the cute canines. One of the main genetic mutations responsible for small size in certain dog breeds, …
* View the article originally published here. ** More curations: Al Cannistra at San Antonio ONE here.