Dolphins' big brains evolved in spurts

Dolphins' big brains evolved in spurts (New Scientist: 29-Oct-04)
Dolphins have evolved surprisingly big brains over the last 47 million years, according to the largest fossil study ever done on the animals. The growth - which occurred in two spurts - may shed light on how humans became so brainy.
An fine example of Punctuated Eek-eek-eek-eek-equilibrium!