A ballistic calculation required to make an accurate throw is so deucedly complicated that we are the only animal that does it as well as we do. Not only is the arm angle and force important, the release window is thousandths of a second, yet we do it easily.
Professor William Calvin has suggested that the feedback loop of throwing is what set us on the path to modern humanity. First, it requires a lot of brain power, and second a shoulder designed partially for walking like a chimp's is inefficient for throwing. Throwing probably was a contributor to our fully bipedal stance and our bigger brain.
The most popular human tool -- ever -- was the so-called hand-axe, used by first homo erectus and then by homo sapiens and neanderthalensis for 1.5 million years. Its unchanging design suggests it was optimized and couldn't be improved. Dr. Calvin has discovered that it makes a perfect thrown weapon, a characteristic that would not have escaped our ancestors for a million or so years.
Throwing is what made us human.