Processing of meat helped us out on people – rmf24.pl

Who would have thought that our delicate appearance, intelligence and ability to speak … we owe skills preparing meals? And yet it is precisely the fact that our distant ancestors switch over your diet for meat, which could so prepare to give a quick bite, there was of decisive importance. That, at least, in a letter published in the journal “Nature” say researchers at Harvard University. It says – let us add – on the basis of a fairly exhaustive experiments.

Modern methods of food preparation, make eating does not have to be specially tired. In the case of our closest relatives, the chimpanzees, the situation is completely different. Chimpanzees spend on chewing food almost half a day and need to put in the operation much more strength. Katie Zink and Daniel Lieberman of the Department of Human Evolutionary Biology, Harvard University write that a significant change in the habits of our ancestors occurred 2 to 3 million years ago, and since then human evolution greatly accelerated.

The results of their research show that the shift in the diet of meat and use for its preparation known the tools that made our ancestors did not have it constantly chew, while receiving the meals much more energy.

the meals have become shorter, the food stopped require such force jaw, which meant that we gradually wydelikatniały features, changed the structure of the skull, and in particular the jaws. On the one hand, it has helped in the development of a much larger brain, the other allowing to save time on the other, we gradually developing forms of activity. Among other things, this probably evolved in question, which meant that we could evolve even faster.

Same tests were not pleasant nor scientists, nor for the participating volunteers. The subjects were asked to chew different types of food, including raw meat, then spits them to scientists to carefully analyze what the food was.

Results of these analyzes indicate that in the diet about 33 percent of the meat and the use of simple tools for cutting and breaking the pieces of meat or plants reduced the necessary amount of action of the jaws as well as necessary during this strength up to 20 percent. Our ancestors swallow thanks to smaller portions, that their bodies were better able to take advantage of. All this meant that the amount supplied the body in the form of food energy increased by decreasing the effort needed to eat.

Eating meat processed with the help of stone tools has allowed a gradual reduction in the size of the jaws and teeth, as well as weight reduction needed for chewing muscles – explains the first author of the work, Katie Zink. We have found that modern people, with the help of present teeth, they are not able to effectively chew raw meat – adds professor Daniel Lieberman. But it is enough that they will cut, and the effects of chewing grow dramatically – said.

According to the researchers, it is the ability simple mechanical processing of the meat, and then also his cooking on the fire meant that the original man could begin to create a growing community of collectors and hunters. It accelerated the anatomical changes his skull, jaw reduction needed to chew and to increase the volume available to the brain. The development of speech and intelligence were the natural consequence.