Scratches show earliest evidence of right-handedness

Fossil teeth indicate the earliest evidence of right-handedness in Homo habilis.
1.8 million year old fossil teeth indicate right-handedness. (David Fayer)

About 90 percent of us are right-handed. But the dominance of right-handedness in the population is a very human trait in that it separates us from our ape relatives. Their populations show no dominance of one hand over the other.

So scientists have wondered how far back this dominance of right-handedness goes, and what it tells us about our evolutionary lineage.

A new study might shed light on this mystery. Dr. David Frayer, a professor emeritus in anthropology from The University of Kansas has found the earliest fossil evidence for right-handedness. The clue came from a very early hand-to-mouth existence.