A study by researchers from the University of Georgia has found that genomes of snake species, including constrictor and the king cobra, include genes for limbs. According to the study, snakes still have DNA crucial to limb development lurking in their genomes.

Kim Cooper, a biologist at University of California, San Diego, and expert in genetics of limb development, said, "Developmental biologists are only beginning to understand how complex are the instructions for gene expression. Does each gene have a different enhancer for each place and time in development, or are some enhancers read again and again".

Douglas Menke, an assistant professor of genetics in university's Franklin College of Arts and Sciences and study's lead author, said it is believed that snakes were always legless, which is not true. Millions of years ago, the snakes have evolved to limbless. Many generations of snakes have passed, and snakes species that we are seeing today are different, Menke added.

According to Menke, after looking at DNA sequences of snakes, it can be concluded that the reptile retains a number of enhancers that snake experts thought were limb enhancers. Many generations of snakes have passed, but these elements are still present in snakes. These elements could force researchers to think deeply on what limb enhancers are doing the reptile, limb enhancers are doing in snakes added.

Menke concluded that the study has provided important information on why today's snake species still have the genetic blueprints for limb development in their genome.

He also adds, "From purely looking at the DNA sequences we can conclude that snakes retain many enhancers that, based on mammalian studies, we thought were limb enhancers. There have been tens of millions of generations for these elements to be lost, but the fact that these are still present in snakes prompted us to rethink what these limb enhancers are doing in snakes and mice."