Snakes evolved from limbed lizards. The Hox gene, which affects whether animals have limbs, was thought to have been disrupted in snakes bringing about their long, limbless bodies.
However, P. David Polly of IU and Jason Head of Nebraska discovered that’s not the case, according to an IU press release.
If snakes lost their limbs because the Hox gene was disrupted, then researchers could expect to find that the snakes’ skeletons wouldn’t have regions of bones that correspond to their ancestors’ limbs. Polly and Head found the opposite: regionalized skeletons.
“Snakes have the same number of regions and in the same places in the vertebral column as limbed lizards,” Head said in the release.
The finding suggests Hox genes are working in snakes, he said. Some of the regions they found in snakes matched with their lizard cousins.
Polly said in the release that mammals, lizards and birds developed limbs and other skeletal regions in addition to the effects of the Hox gene. Lay said people’s eyes might glaze over at that, but he said it’s a significant discovery for researchers in developmental genetics.
“Our findings turn the sequence of evolutionary events on its head,” Polly said.
Gage Bentley
