Most kids in the U.S. at some point learn the story of Balto, the Siberian Husky who heroically led a team of sled dogs to Nome, Alaska, to deliver lifesaving diphtheria medicine to its residents.

(I don't know about you but I read my copy of "The Bravest Dog Ever" to tatters.)

Now genetic scientists have discovered how Balto was able to be such a relentless leader in the Alaskan sled-dog hierarchy:

In a study published on Thursday in Science, biologists found that Balto's genome is more diverse — and ultimately healthier — than that of most dog breeds today. His genes also suggest that he and his intrepid canine comrades in the 1920s had multiple traits that made them more fit to travel and survive in a harsh environment.

Scientists also found within his genome "protein-altering, evolutionarily constrained variants," ones that selected for "bone and tissue development, including skin thickness, body weight, coordination and joint formation." In other words, the pooch was tailor-made for the sort of brutal, relentless environmental conditions of the Alaskan outback.

It also turns out that he had "less inbreeding than modern dog breeds tend to be," meaning his overall genetic profile was healthier.

Of course, we needed none of this to let us learn that Balto was an absolute Chad on the trail. We knew that already. Still, as one researcher put it:

It was great to be able to see that [the results were] sort of consistent with what we knew about Balto already.