AP BIOLOGY

Detailed explanation-1: -Snakes are thought to have evolved from either burrowing or aquatic lizards, perhaps during the Jurassic period, with the earliest known fossils dating to between 143 and 167 Ma ago.

Detailed explanation-2: -The evolution of a long, legless body could be beneficial to life underwater as it would enable eel-like swimming. But it could also be beneficial on land, making burrowing and hunting underground easier.

Detailed explanation-3: -According to the theory, predatory pressure from snakes has selected individuals who are better able to recognize them, improving their survival chances and therefore transferring such skill to their offspring.

Detailed explanation-4: -Reptiles originally descended from early limbed vertebrates that invaded the land about 70 million years before the Mesozoic (Benton 2004). These reptilian ancestors lost their gills at one point in time, so their descendents could not breathe in water unlike fish or some amphibians.