Athens, Ga. - When researchers at the University of Georgia examined the genome of several different snake species, they found something surprising. Embedded in reptiles' genetic code was DNA that, in ...

The shared patterns of gene expression in the limbs and phallus are generated in part by a common set of noncoding DNA, also called 'elements' or 'enhancers,' which act to control gene expression in ...

Hundreds of millions of years ago, a common ancestor of mammals, birds, and reptiles evolved a phallus. We don't know much about phallus evolution (external genitalia generally don't mineralize, so ...

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, but ...

Less than 100 million years after vertebrates first grew legs, some of their descendants had evolved to lose them again, fossils reveal. The discovery shows that land vertebrates first began to evolve ...