How social behavior affects genetic makeup

Scientists studying bottlenose dolphins that use sponges as  tools to protect their sensitive beaks has shown that social behavior can shape  the genetic makeup of an animal population in the wild.

The study has been carried out on dolphins in Shark Bay in  Western Australia. With many of these bottlenose dolphins, the mammals put  conical marine sponges on their rostrums (beaks) when they forage on the sea  floor. This is a non-genetic skill that calves apparently learn from their  mother.

However, a team of researchers have  found that sponging dolphins end up with some genetic similarities because the  calves also inherit DNA from their mothers. It is also likely that sponging  dolphins are descendants of a female dolphin that first developed the  innovation.

Bottlenose dolphins live in groups typically of 10–30  members, called pods, but group size varies from single individuals up to more  than 1,000. Their diets consist mainly of forage fish. Dolphins often work as a  team to harvest fish schools, but they also hunt individually. Bottlenose  dolphins also use sound for communication, including squeaks and whistles  emitted from the blowhole and sounds emitted through body language, such as  leaping from the water and slapping their tails on the water surface.