Uncovering the Genetic Secrets of Balto, the Heroic Sled Dog.

A DNA study of Balto, a sled dog who helped carry life-saving medicine through blizzards in 1925, has revealed that he had fewer potentially dangerous mutations than modern breeds of dogs, suggesting he was healthier. Contrary to a legend that held that Balto was half wolf, the analysis found no evidence he had wolf blood. Balto shared ancestors with modern-day Siberian Huskies and the sled dogs of Alaska and Greenland. The study also compared Balto's genes with the genomes of 240 other species of mammals, allowing researchers to determine which DNA fragments were common across all those species.