- They are extremely smart
- They are able to use tools
- They recognize themselves
- They communicate with each other
- They communicate with human trainers
Dolphins significantly altered over 200 of the 10,000 genes surveyed. Twenty-seven changes affected the nervous system. Many changes were related to metabolism, which is significant because the brain uses more energy than other tissues. Although these changes do not prove that they are responsible for the superb thinking ability of dolphins, they do point in that direction.
The researchers were surprised to find that, overall, dolphins were evolving more slowly than many other animals, a characteristic of other mammals with large brains such as primates and elephants.. This may be explained by the tendency of big-brained mammals to invest more in their offspring and have fewer babies, a trend which itself leads to slower evolution.
The research is detailed in the June 27 issue of the journal Proceedings of the Royal Society B: Biological Sciences and was reported in LiveScience by Jennifer Welsh.