Overhand throw - our evolutionary edge?

From the NY Times and Harvard University:

No one knows whether Homo erectus, the early ancestor of both the Yankees and the Red Sox, threw the split-finger fastball. But he could have, according to a group of scientists who offer new evidence that the classic overhand throw used by baseball players at all positions, ....
They first appeared, the researchers say,around 1.8 million years ago, when humans were most likely beginning to hunt big game and needed to throw sharp objects hard and fast.