Sea Snails Break The Law
Lizards gave rise to legless snakes. Cave fishes don't have eyeballs. In evolution, complicated structures often get lost. Dollo's Law states that complicated structures can't be re-evolved because the genes that code for them were lost or have mutated. A group of sea snails breaks Dollo's law, Rachel Collin, Staff Scientist at the Smithsonian Tropical Research Institute and colleagues from two Chilean universities announce in the April, 2007, Biological Bulletin.
"This is important because it shows that animals may carry the potential for evolutionary change around with them. When the environment changes, new life forms may be able to regain abilities that were lost earlier in evolutionary history," Collin explains.