Snakes Use 'Leg Genes' to Make Phalluses

Snakes lack limbs, but new research finds that they still have DNA crucial to limb development lurking in their genomes.

October 5, 2015
3:30 PM EDT
Shown is the embryo of a corn snake, injected with a special tracer that shows the expression of the gene Tbx4 (in purple). This gene is important for the development of the limbs in mammals and lizards. | Carlos R. Infante