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Whales really are smart

The rich social interaction and highly evolved brains of some whales are linked in a kind of evolutionary feedback loop, a newly published paper suggests.

The research, largely done at the University of British Columbia, sheds new light on similarities between whale and human evolution.

"Similar pressures and possibilities in the environment can select for a similar outcome," said Kieran Fox, now a postdoctoral student at California's Stanford University and co-author of the new paper in Nature Ecology and Evolution.

Fox and his colleagues studied brain sizes and social behaviours of a wide variety of whale species. They found that whales with the most complex forms of social interaction — which includes learning from elders, social hierarchies, co-operation and play — tend to live in mid-sized groups of between five and 20. In species such as orcas, individuals have extended one-on-one contact required to develop social behaviour.

"Orcas are in matrilineal family clans," Fox said. "These groups stay together, very tight-knit, through their whole lives."

In addition, Fox found that whales with the largest "social repertoire" also have the largest and most developed brains relative to their bodies.

But which came first, the bigger brain or the richer relationships? Fox said his research suggests the two go hand in hand. Learning beneficial new skills or social behaviours eventually requires a larger, more powerful brain. And a species that evolves a more powerful brain is better able to learn or develop relationships.

"That's the theory to this extremely powerful driver of brain evolution — once it gets going, you get some brain tissue that supports (social skills), then these individuals are going to do really, really well, because social co-operation and learning are very powerful survival strategies."

Fox calls the effect a positive feedback loop.

Humans are the classic example of how the link between powerful brains and rich, adaptive cultures can create a smashing evolutionary success. Fox said his research shows how the same process may be at work in a completely different environment and species.

Whales aren't the only example of this kind of evolutionary strategy. Some primates and elephants also possess it, said Fox.

"A very different species in a totally different environment, diverging millions and millions of years ago, can nonetheless be selected for this very similar life strategy."



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