Chimp "Sex Toys" As Evolution Evidence

This is not a joke, but an actual article in the New York Times suggesting that male chimps, by using leaves to attract females to certain body parts, show us an "evolutionary leap" and delivers the "most devastating blow yet to human self-esteem."

Caution: Link does contain suggestive material

When It Comes to Sex, Chimps Need Help, Too

"I couldn’t imagine how chimps managed this evolutionary leap. But then, I couldn’t imagine what they were actually doing. Using blades of grass to tickle one another? Building heart-shaped beds of moss? Using stones for massages, or vines for bondage, or — well, I really had no idea, so I called Dr. McGrew, who is a professor at the University of Cambridge.

The tool for sex, he explained, is a leaf. Ideally a dead leaf, because that makes the most noise when the chimp clips it with his hand or his mouth."

So, how is your self-esteem now? Apparently I don't know what I'm missing.