Dolphins use sponges as nose guards and it's changing their genes

Dolphins are known for being clever and resourceful, but one particularly interesting population in Shark Bay, Western Australia, is famous for using sponges as nose-guards while foraging. It's a non-genetic behaviour, which means calves learn it from their mothers.

But a study by researchers at the University of New South Wales (UNSW) has found that the genetic makeup of the sponge-using dolphins is significantly different to groups that live where sponges don't grow, suggesting the behaviour has actually shaped the population's genes.

The research, published in Proceedings of the Royal Society B, looks at the dolphins mitochondrial DNA, which is passed down only from the mother, and also indicates that the sponging dolphins are descendants of a "sponging Eve", a female dolphin that first developed the innovation.

The press release explains:

“Our research shows that social learning should be considered as a possible factor that shapes the genetic structure of a wild animal population,” says Dr Anna Kopps, lead author of the study.

“It is one of the first studies to show this effect – which is called cultural hitchhiking – in animals other than people.”

This is just another piece to add to the fascinating puzzle of how learning and our environment shape genes.

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