Why we are equipped for a third eyelid and an ear that is made to be able to run

Animals The human being is in evolution and is also, of course, already considerably evolved since the origin of primates. But we are still some physical remains on to already long teloorgegane bodily functions. “Evolutionary leftovers”, called Dorsa Amir, an evolutionary anthropologist, she. Did you know for example, that we are ever our ears could rotate? Or that we have a third eyelid?

The most famous remnant is probably our staartbeentje. That name is not chosen at random. Because we humans since we walk upright, no tail, more necessary to our balance, which is our tail in the course of time simply disappeared. However, we are still born with a witness to it in our skeleton at the bottom of the spine: the tailbone, or the coccyx. As an embryo develops, the man even still with a tail between five and eight weeks after conception. But that disappears again, but not always. The longest tail ever in humans is measured, is 33 inches long.

another, much less well-known vestigial human attribute is our third eyelid. The so-called plica semilunaris is the “evolutionary remnant” thereof, a weefselplooi in the inner corner of the eye. It seems on the membranes of certain reptiles, birds and even mammals use their eyes to protect. Today the man has the muscles but not the diaphragm horizontally over the eye to clean and moist to keep. According to dr. Dorsa Amir of Boston College we have our third eyelid for a very long time ago kwijtgespeeld, because it is also “rare in primates”.