Abstract

The domestication of dogs from wolves is, arguably, the most successful scientific experiment undertaken in human history. Dogs were domesticated 30,000 years ago and most breeds were developed only 200 years ago. Now our planet is populated with millions of dogs representing 350 breeds, village dogs, feral dogs and mixed breed dogs. Key to understanding canine variation is the study of modern and ancient genomes sampled from dogs around the world. Our studies encompass evolution, genomics and genetics, as we seek to understand how dog breeds have been shaped by humans, why some breeds are prone to specific diseases, and what accounts for the striking differences in appearance and behavior observed between breeds. By studying the genome sequence of modern and ancient dogs we show that most breed-defining traits, such as body size, leg length, coat color, etc., are controlled by small numbers of genes of large effect, and that most of these genes are also relevant for human health and biology. Studies of constraint in 2400 whole genome sequenced dogs identify invariant regions of the dog genome that, when mutated, affect gene function. Studies of isolated dog populations, such as those at Chernobyl, reveal new insights into how dogs live in otherwise hostile environments, and studies of modern and historical dogs from the Galápagos Islands reveal new insights into conservation strategies.