Neanderthal lefties

According to Yahoo News, some of the oldest evidence of left-handedness comes from Kenya, where of a 500,000 year old cache of 54 stone tools made by one of our pre-human ancestors, six (or about 11 percent) were chipped using the left hand.

Similarly, Neanderthals working with meat and stone tools more than 150,000 years ago left marks on their teeth at left and right angles - indicating opposite hand use - in almost perfect proportion with today's 9:1 ratio.

In the Yahoo story, it mentions that Paleolithic cave paintings from France and Spain also hint that there were lefties about 30,000 years ago. Studying a collection of so-called negative hand drawings on the cave walls - similar to tracing one hand with the other - scientists found that individuals drew their left hand much more frequently than the right.