Oct. 16 (UPI) -- Whale and dolphin societies are rich, complex and remarkably "human-like," scientists argue in a new paper published this week in the journal Nature Ecology & Evolution.
As detailed in the new paper, the social lives of whales and dolphins check many of the same boxes that make human societies so unique. They live among family and friends in closely knit groups. They form complex relationships across their social groups. They talk to each other and develop and even develop regional dialects.
"As humans, our ability to socially interact and cultivate relationships has allowed us to colonize almost every ecosystem and environment on the planet," Susanne Shultz, an evolutionary biologist at the University of Manchester in England, said in a news release. "We know whales and dolphins also have exceptionally large and anatomically sophisticated brains and, therefore, have created a similar marine based culture."
Like humans, skills and knowledge are passed from generation to generation among whales and dolphins, not through genes but culturally -- through show and tell. Whales and dolphins use their skills and knowledge to cooperate for one another's mutual benefit.
Whales and dolphins also hunt in groups, as well as cooperate with other species, including humans. What's more, they engage in social play and look after offspring that aren't their own.
"The apparent co-evolution of brains, social structure, and behavioral richness of marine mammals provides a unique and striking parallel to the large brains and hyper-sociality of humans and other primates on land," Shultz said. "Unfortunately, they won't ever mimic our great metropolises and technologies because they didn't evolve opposable thumbs."
Many scientists believe that the expansion of the human brain and the increasing social nature of human existence worked like a positive feedback loop, with each phenomenon accelerating the other. Biologists suggest the development of dolphin and whale brains happened in much the same way.
The research marks the first time scientists have used the social brain hypothesis and cultural brain hypothesis -- previously used to analyze the evolution of primates and land mammals -- to study marine mammals.
But while the latest research highlights remarkable similarities between humans and cetaceans, the class of aquatic mammals that includes dolphins, whales and porpoises, the findings will also help scientists better understand what makes humans unique.
"In order to move toward a more general theory of human behavior, we need to understand what makes humans so different from other animals," said Michael Muthukrishna, assistant professor of economic psychology at the London School of Economics. "And to do this, we need a control group. Compared to primates, cetaceans are a more 'alien' control group."
The brain structures of whales and dolphins are quite different than those of humans, leading some scientists to argue cetaceans were incapable of complex social intelligence.
"I think our research shows that this is clearly not the case," said Kieran Fox, a neuroscientist at Stanford University. "Instead, a new question emerges: How can very diverse patterns of brain structure in very different species nonetheless give rise to highly similar cognitive and social behaviors?"