Thursday, September 26, 2019
Losing Genes Helped Whales Adapt to Underwater Life
Scientists in Germany began to study whales and dolphins and piece together what made them go from land living creatures to water inhabitants about 50 million years ago. They studied the DNA and gene differences between modern day whales and hippos, which are the closest ancestors to 'land living whales' or land living cetaceans. The study found that whales actually "lost" as many as 85 genes that affected physical processes that would be a burden in full time water life. One example dealt with the POLM genes, which regulate the repair of DNA, but is also very damage prone. This is important because DNA gets damaged with cycles of high to low oxygen. So getting rid of an inefficient protein would only help them make that transition from land to sea. Another gene that was lost was SLC4A9, which regulated saliva production. Saliva helps break down food, which unnecessary in water. Also, less saliva helps keep fresh water in the body. This gene would be beneficial to lose in the water.
I think this article really highlights how the environments affects both evolution and genetics. Simply changing environments completely changes how an animal operates and lives. It is important to see how environmental changes affected animals in the past and predict how they can impact others in the future.