HAND BONE MORPHOLOGY IN HUMAN´S EVOLUTION

Humans are not the only animals that are able to use tools, but it is the one who use them more efficiently than any other species in the world. This ability is not only due to the highly developed brains, it is also because of the special morphology of our hands. 

One discovery of a hand bone of 1,42 million years old proves it. These results came from the autor Carol Ward from the University of Missouri and were published in Proceedings of the National Academy of Sciences.

This discovery was carried up in Kenia where a 1.42 million year old metacarpal bone was discovered. By making different probes, researchers determined that it was of a Homo Erectus hominids, and presented a very important feature; a styloid process.

 This process is a small bony bump at the proximal end of the bone, which can be found in different bones of the body. In the hand, it connects the hand to the wrist and allows much more pressure force when hand is gripping an object. This feature, allows making and using objects more efficiently.

This discovery is very important because there was no evidence of this process in a more ancient hominid. Concretely, it was seen in Neanderthals, but it was not clear when was it formed.  In the place where metacarpal bone was discovered, there were many stone tools that reach as far back as 1.6 million years ago.

ARTICLE: http://www.pnas.org/content/111/1/121.abstract