It’s all in the genes. And a bottlenose dolphin’s genes tell the story of just how smart these distant cousins of ours may be – smarter even than our close cousins the chimpanzees … and maybe even smarter than homo sapiens.[readon]
Last fall, a team at Wayne State University in Michigan completed the first sequencing of the bottlenose dolphin genome. And now they’ve compared 10,000 of their genes with nine other animals: the cow, horse, dog, mouse, human, elephant, opossum, platypus and chicken.
Cows are the dolphin’s closest relatives with a sequenced genome. And in particular, the scientists were looking for how dolphin genes had mutated over the ages from their cousins. What they found was that 228 of the genes in their survey were drastically changed in the dolphins. Twenty-seven of these were involved in the nervous system – the brain and sensory organs. And there were changes in the genes related to metabolism since brain tissue uses more energy than other tissues.
All of this suggests that dolphins evolved to be super-intelligent.
“Changes in these genes could have led to the amazing cognitive capacity seen in dolphins,” lead researcher Michael McGowen said. “It definitely points in that direction.”
One group of genes seems to be important for forming synapses in the brain, and another relates to the bizarre way dolphins sleep with one eye open and half the brain on hiatus. Another set of genes corresponds to genes that in humans are related to certain brain disorders, including Alzheimer’s and schizophrenia.
“Any sort of gene that will affect intellectual abilities in humans signals that they may be important in cognitive functions in general,” McGowen said.
We don’t know everything that dolphins do with their intelligence, but we do know that it takes a whole lot of brainpower for them to lead their intensely complex social lives, full of Machiavellian politics and switching alliances. And while we don’t know if they have the same kind of language as we humans, we do know that their communication skills are very high and that they use forms of communication – like advanced echolocation – that are entirely alien to us.
The full study is in the Proceedings of the Royal Society B.