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Throwing objects at predators or prey allowed human ancestors to stop climbing trees, study in journal Nature says.
We always suspected there was something wrong with the Matt LeBlanc movie “Ed,” but chalked it up to script issues. Now we have scientific proof: chimpanzees can’t play baseball because of their weak shoulder muscles.
Researchers wanted to know why humans throw so well, but our primate cousins can climb with such ease.
It began when an ape-human-like creature, Australopithecus afarensis, developed a more mobile waistline, study co-author Madhusudhan Venkadesan told Discovery.
Homo erectus, or “Upright man,” then translated the bendy waist into the ability to walk, run and throw about two million years ago.
“Tree climbing requires large, powerful muscles with different demands on force production and perhaps reduces the range of motion at the shoulder and precludes the kind of throw that a baseball pitcher does,” said Venkadesan, also an assistant professor at the National Center for Biological Sciences in India.
Chimps, for example, can only throw about 20 mph, compared to 90 mph for the professional baseball players.
That prowess on the diamond came when our ancestors started hunting, the Guardian reported.
“Upright man” also developed lower, wider shoulders, an expanded waist and the ability to twist the arm bone. It explains why chimpanzees resemble your five-foot-six grandfather wobbling around in an ill-fitting suit and tie ordering another drink at the supper club.
“When humans throw, we first rotate our arms backwards away from the target,” said the study’s lead researcher, Neil Roach from George Washington University.
“It is during this ‘arm-cocking’ phase that humans stretch the tendons and ligaments crossing their shoulder and store elastic energy. When this energy is released, it accelerates the arm forward, generating the fastest motion the human body produces, resulting in a very fast throw.”
This evolutionary change was a key to humankind’s superiority, Jessica Thompson, an archaeology researcher at the University of Queensland in Australia, told USA Today.
With our abilities to throw, we didn’t have to worry so much about hiding from predators by climbing trees.
“Throwing is a classic example of how human biological evolution has been shaped by both technology and behavior,” said Thompson, who wasn’t part of the research.
One issue still unresolved, however, is what were our ancestors throwing?
Spear artifacts only appear about 400,000 years ago, and our brains two million years ago weren’t developed enough to master the complicated task of throwing at a moving target.
“So what is it that we were throwing and how is that we were killing these animals?” Roach said at USAToday.com “What happens when you kill with a sharpened wooden stick? Can you actually do it? What energy is required?”
That, he admits, is subject for further study.