Uncertainties About Human Evolution II
The evolution of the brain is the most important change. This is what makes us humans, and some believe that this is why we left Africa.
The bigger the brain is, the more energy it requires. In a way we were forced to leave the area in order to feed our brain, to survive. The primates seem to know the importance of food as well. They only eat the top quality foods, the ones which are suitable for their bodies. They consume the leaves which are very rich in proteins, the fruits which have lots of calories, and they avoid the plants which are very rich in fibers. These animals which can make such selections have higher brains than the ones that will eat anything that they can set their eyes on.

Then there is the belief that we changed because the climate changed. From a very hot environment we were forced to live in a cold one. That obliged us to stand on our two feet in order to make sure that we see the incoming dangers. It was said that the reason why we started using our hands was because we needed to gather as much food as possible. The babies were a reason of concern as well, as they needed to be carried by their mothers. However, it seems that the humans were not the first of their kind to walk on two legs. The orangutans do it as well when they walk on the branches of the trees. The brain size is very important as well. It is unknown why the brains increased in size. Certain theories say that the reason why our brains increased is because we had to face new challenges. From a physical point of view, our brains increased because we lost our bodily hair, which would prevent us from sweating, which on return would keep our brain cool. It was also said that the reason why our brain size increased was because of the fact that our jaw muscles lost strength and size and as a result the cranium was free to grow.

Chris Stringer, head of human origins at the Natural History Museum believes that the reason why our brains increased was because of our social connections. We needed a bigger brain in order to establish social relationships and in order to make the distinction between friends and enemies. They needed bigger brains in order to hunt successfully and to outsmart the animals. They needed bigger brains in order to invent helpful things such as the fire. After a while the humans started to develop the language. It was recently discovered that language has only one origin: Africa. It was believed for a very long time that language appeared in different areas at different moments, but all the languages of the world come from the same mother language.
The modern humans are pretty young as they appeared 60,000 years ago. The place where they were born: Africa. It was discovered that about 30,000 years ago they started using more advanced types of tools made out of shells and bones. They started painting, they developed religions. For a certain period of time, modern humans lived with Neanderthals and they might have even mated. Then all of a sudden the modern humans were alone on this planet, all the other types of humans being extinct. The end.11
