The sled dog Balto has been celebrated in books and movies for his role in delivering desperately needed diphtheria antitoxin to Nome, Alaska, in 1925. He belonged to a population of small, fast, and fit sled dogs imported from Siberia. By sequencing his genome from his taxidermied remains and analyzing these data in the context of large comparative and canine datasets, scientists now show that Balto and his working sled dog contemporaries were more...
