The dolphin’s brain structurally has two section, each with two lobes. Both of these lobes has a seperate blood supply, and in fact, can even be considered to be completely seperate brains. According to researcher Carol J. Howard, Dolphins never sleep with both parts of their brain simultaneously. In fact, when a Dolphin sleeps, one of the sides of it’s brain completely shuts down, while the other stays alert in order to run the various body functions. Each of the dolphin’s eyes is connected to a different side of the brain. Because of that, a Dolphin can still see when it is sleeping, making it difficult for predators to sneak up on it. – allaboutdolphins.net
Dolphins are so distantly related to humans that it’s been 95 million years since we had even a remotely common ancestor. Yet when it comes to intelligence, social behavior and communications, some researchers say dolphins come as close to humans as our ape and monkey cousins.
“They understand concepts like zero, abstract concepts. They do everything that chimpanzees do and bonobos can do,” said Lori Marino, a neuroscientist at Emory University who specializes in dolphin research. “The fact is that they are so different from us and so much like us at the same time.”
In recent years, animal researchers have found that thought processes in critters aren’t a matter of how closely related they are to humans. You don’t have to be a primate to be smart.
Dolphin brains look nothing like human brains, Marino said. Yet, she says, “the more you learn about them, the more you realize that they do have the capacity and characteristics that we think of when we think of a person.”
These mammals recognize themselves in the mirror and have a sense of social identity. They not only know who they are, but they also have a sense of who, where and what their groups are. They interact and comprehend the health and feelings of other dolphins so fast it as if they are online with each other, Marino said.
Animal intelligence “is not a linear thing,” said Duke University researcher Brian Hare, who studies bonobos, which are one of man’s closest relatives, and dogs, which are not.
“Think of it like a toolbox,” he said. “Some species have an amazing hammer. Some species have an amazing screwdriver.”
For dogs, a primary tool is their obsessive observation of humans and ability to understand human communication, Hare said. For example, dogs follow human pointing so well that they understand it whether it’s done with a hand or a foot; chimps don’t, said Hare, whose upcoming book is called “The Genius of Dogs.”
Then there are elephants.
via Complex thinking goes beyond primates: Dolphins understand zero, elephants rescue each other – The Washington Post.