How has the shape of the human shoulder propelled us to the top of the animal kingdom?
Throughout
history, human ancestors did not always possess the ability to throw, a skill
that propelled them to the top of the animal kingdom. This skill is based in
the shape of the shoulder joint. In apes, this joint opens
upwards, making it ideal for hanging on trees, but incapable of accurate
projection. As humanoids turned to walking as their primary means of
transportation, the joints and shoulder blades slowly fell. Approximately
500,000 years ago, they arrived in their present horizontal, coat-hanger-like
position.
Ape shoulder (top) and human shoulder (bottom)
With a joint that opened horizontally, instead of vertically, early humans were able to rotate their arms in an almost any direction. This semi-boundless motion allowed them to throw with an accuracy much greater than that of their ancestors. Apes are known to throw rocks, but soon humanoids began to hunt with wooden spears, placing them at a great advantage over any other animal.
The use of projectile weapons was one major difference between Neanderthals and modern humans. In the midst of their relatively rapid evolution, it is possible that Neanderthals' bodies never evolved to allow accurate throwing. It is hypothesized that their shoulders were much more ape-like in shape and position. According to Steven Churchill, an anthropology professor at Duke University, "Perhaps their...short, squat body build with short and massive limbs was not conducive to using throwing-based hunting technology." The ability to hunt from a distance gave humans a distinct advantage over Neanderthals. We could hunt safely, giving us a higher chance of returning home to reproduce. This is a possible reason for the extinction of Neanderthals, modern humans most formidable rivals; we simply outhunted them.
The one question that seems to be unanswered is a question of "What if?". What if our shoulders had never fallen to their present position? What if we were unable to throw a weapon from a distance and injure or kill our target? Would we be the most dominant species on the planet? Would we still be living alongside Neanderthals? Most importantly, would we still exist at all or would we have been replaced by another species better suited for life on Earth?
With a joint that opened horizontally, instead of vertically, early humans were able to rotate their arms in an almost any direction. This semi-boundless motion allowed them to throw with an accuracy much greater than that of their ancestors. Apes are known to throw rocks, but soon humanoids began to hunt with wooden spears, placing them at a great advantage over any other animal.
The use of projectile weapons was one major difference between Neanderthals and modern humans. In the midst of their relatively rapid evolution, it is possible that Neanderthals' bodies never evolved to allow accurate throwing. It is hypothesized that their shoulders were much more ape-like in shape and position. According to Steven Churchill, an anthropology professor at Duke University, "Perhaps their...short, squat body build with short and massive limbs was not conducive to using throwing-based hunting technology." The ability to hunt from a distance gave humans a distinct advantage over Neanderthals. We could hunt safely, giving us a higher chance of returning home to reproduce. This is a possible reason for the extinction of Neanderthals, modern humans most formidable rivals; we simply outhunted them.
The one question that seems to be unanswered is a question of "What if?". What if our shoulders had never fallen to their present position? What if we were unable to throw a weapon from a distance and injure or kill our target? Would we be the most dominant species on the planet? Would we still be living alongside Neanderthals? Most importantly, would we still exist at all or would we have been replaced by another species better suited for life on Earth?
