"Live-Birthing Snail Sheds Light on Incremental Evolutionary Shifts"

A study on the marine snail Littorina saxatilis, which has evolved to give birth to live young instead of laying eggs, has revealed that this significant evolutionary change occurred gradually over the last 100,000 years through the accumulation of around 50 genetic changes. Researchers used whole-genome sequences to trace the snail's family tree and found that the ability to give birth to live young stood out due to interbreeding among snails, which mixed up the genetic background. This discovery challenges the notion of sudden leaps in evolution, suggesting that major evolutionary transitions can occur through small, incremental steps. The findings have implications for understanding other evolutionary shifts and how species may adapt to changing environments, such as climate change. The study is published in the journal Science.