Did you ever start watching The Cove, but then turn it off because dolphins smile in a way that assures you they're a lot like humans? Then you'll appreciate this new study that confirms you're right. It finds that dolphins, as well as whales and porpoises, teach one another to hunt and use tools and even care for children that aren't their own. But the study also shines light on how advanced brain structures—the kind that allow for this level of sophistication—apparently evolve when animals are social.
The Social and Cultural Roots of Whale and Dolphin Brains appeared in Nature journal on Monday. It brought together scientists from Canada, the US, and the UK who looked at 90 species of Cetaceans (aquatic mammals) to find a range of familiar behavioural traits.
What it found is that Cetaceans regularly work together as a team for mutual benefit. Researchers also found vocalisations that are unique to particular groups, comparable to that of regional dialects in humans. They also identify each other with "signature whistles," in exactly the same way that we humans have names.
But what's most important to the scientists, is what all of this says about the evolution of brains across all species.
Scientists and been arguing about the correlation between brain size and societal complexity since Darwin. The argument is important as it gets a central question in evolutionary biology—and that is: why are humans so different?
For most of the 20th century the basic theory was that humans had just developed big, sophisticated brains via luck. We'd then developed language, which allowed us to plan for the future, and all that forward thinking led to agriculture and cities. But a study released in 1998 argued that maybe we had it all wrong. Because maybe the process of brain evolution wasn't so linear.
Professor Robin Dunbar, from the University of Liverpool, penned the Social Brain Hypothesis, which argued that the interplay between brain development and society was messy. He argued that co-living had possibly occurred first, and that the stress of getting along with each other might have prompted our brains to evolve.
This hypothesis came with a lot of evidence in primates, but nothing from a control group different to humans. And because of that, researchers thought that identifying animals that live in human-like societies, but are nothing like humans, could just about prove the universality of the Social Brain Hypothesis.
And this is why this latest study on whales and dolphins is important.
As Dr Susanne Shultz, evolutionary biologist at the University of Manchester, explained in this news release, "Our ability to socially interact and cultivate relationships has allowed us to colonise almost every ecosystem and environment on the planet. We know whales and dolphins also have exceptionally large and anatomically sophisticated brains and, therefore, have created a similar, marine-based culture."
But will this mean that dolphins and whales will someday evolve to the point of humans? Will they someday build great cities and factory farm krill? Dr Susanne Shultz thinks not. As she writes, "Unfortunately, they won't ever mimic our great metropolises and technologies because they didn't evolve opposable thumbs."