How Snakes Lost Their Legs and How It Relates to Audiology

The evolutionary journey of snakes, and how they lost their legs, occurred over millions of years. Scientists believe it is due to complex genetic changes and environmental adaptations.  

Snakes and lizards share a common ancestor; however, lizards retained their legs over time while snakes did not. This is due to mutations that affected a gene known as the Sonic Hedgehog (SHH) gene, which controls the development of limbs. In lizards, the SHH gene is active, but in snakes, this gene was deactivated due to multiple genetic mutations. In addition, researchers from the University of Edinburgh and the American Museum of Natural History used computed tomography scans to study the inner ear of a 90-million-year-old snake skull! They found that the inner ear of that fossilized snake had a distinctive shape, much like that of modern-day burrowing snakes.

The theories that suggest snakes lost their legs to adapt to an aquatic environment may not be accurate. It seems that the snakes’ evolution may instead have been driven by the need to navigate and hunt in burrows. The inner ear structure, which as we know controls balance and hearing, seems to have contributed strongly to this adaptation to no legs.  

Reference

TOI Lifestyle Desk. (2024) This is how snakes lost their legs. Entertainment Times (accessed December 5, 2024).