A new study published in Science  identifies the single evolutionary event that shortened the legs of Dachshunds, Basset Hounds and other stubby puppies. An extra copy of a gene (Fgf4 retrogene, to be exact), acquired by mutation at least 300 years ago, “causes the overproduction of a protein that disrupts growth during fetal development,” writes Sarah Arnquist, translating the study for a New York Times science blog .
I’m freaked out by efforts to engineer animals to suit our needs—according to Arnquist’s story, one advantage of shorter legs in Basset Hounds was allowing hunting humans on horseback to keep up. Plus, it’s hard to ignore the costs of tinkering. Last year’s BBC documentary, “Pedigree Dogs Exposed ,” revealed just a few of the devastating health consequences of breeding for exaggerated physical characteristics.
But, all that said, these results have significant implications. First, it’s more evidence that all the investment of time and money in creating a dog genome  is paying off. Secondly, discovering the gene behind Chondrodysplasia in dogs probably holds important clues into dwarfism in humans. I think it’s fascinating that dogs, so helpful to us in our everyday life as companions and assistants, are providing important keys to unlocking human health mysteries.