Biologists from the Institute of Utah was beaten with the hands of corpses on gantela - this experience was supposed to represent the latest evidence that the hand of the inhabitant of our planet acquired its own shape (in the course of evolution) as a consequence of fist fights that the males fought over females.
The latest data are presented in the journal of Experimental Biology. This planet is distinguished from apes are conditionally short brush and long, strong and flexible thumbs. Traditionally they say that these features were formed when the ancestors of Homo sapiens trained to handle with stone tools. But David Kerrier (David Carrier) is convinced that I have own form in consequence of fist fights. Not to mention the fact that the evolution of Australopithecus individuals (forefathers of man) was dictated by the need to defend himself from the punches. After that, as the reduction of intraspecific aggression and face the forefathers of Homo sapiens became more subtle.
Own experiment Kerrier wanted to demonstrate that a clenched fist is better protects metacarpal hand bones from injury by reducing pressure on them at impact. Specifically these bones (not the fingers) were most affected by the fighting.
The scientist and his students received the donor program of the Institute 9 hands, cut from dead adult men. The hands were dissected, exposing the muscles and attaching them to the sensor deformation. Then the brush was placed in a specialized machine similar to a pendulum, where they swung hit the dumbbells are equipped with sensors the force of impact. On gentely beat compressed and relaxed his fist (the knuckles), also backhand (palm).
After a few hundred strokes, it was discovered that a clenched fist lets you bash with a force of 55 per cent greater than the force of impact knuckles, and 100 percent - chop. Kerrier believes that changes in the anatomy of the hands of the forefathers of Homo not only gave her the win but also made it possible to use the hand as a weapon in fights.
Taking into account the opinion Carrier, the experiments confirm the suitability of a fist to use in the role of weapons, not inferior to sticks and stones - also weapons for hunting and war, and specifically to determine the relationship between males within the team. The difference in the size of the hands, also in power of the muscles of the upper body between men and women is a further proof of this hypothesis, says the biologist.
sections: Society, World News