Hyenas are fascinating in many ways, such as the way female spotted hyenas are equipped with a penis of sorts (pdf). In tomorrow's New York Times, I look at a new kind of fascination: hyena brains. Hyenas have a remarkably complex social life, and it appears to have altered the shape and size of their brains. The same social forces were at work in our own ancestors. Humans and hyenas, in other words, have been rolling on parallel evolutionary tracks. For further details, check out the densely packed web site of Kay Holekamp, the biologist who has been investigating the social hyena brain. And don't miss the slide show the Times has put together for my article.