It’s Shark Week, so I made a visit to my friend Jon Mallatt. He’s a Washington State University biologist who has studied the jaws of ancient sharks.

Jon Mallatt: Some of them, such as tiger sharks, cat sharks, and even great white sharks, have quite large brains—relative to their body weight— and are intelligent. They are not “primitive” animals. The shark relatives, Manta rays and devil rays, have even larger brains than any shark.

Dr. U: How long have sharks been around, anyways?

JM: At least 420 million years and maybe 460. It is … » More …

Read More ...