Through the use of molecular biology in the human brain, human family is thought to have first appeared about 5 million years ago. Based on this time frame, it is believed that there was about 10 myp in African human strain, just before this, including common ancestors of chimpanzees and humans. During the last million years of the Miocene, it divided into native chimpanzees and primitive humans. (Changeux and Chavaillon, p. 61). From this period, fossils, especially fossils of the skull are limited.
Many evidence points out the simple fact that a single human brain itself can not design more intelligence than itself. This is a purely empirical statement: billions of people came and no one did this. Clearly, one human's wisdom can not design intelligence in his lifetime. However, these billions of brains who have accumulated knowledge for thousands of years and have developed external intelligence processes have performed system - civilization. The whole civilization is neither you, me nor an individual, it will produce superhuman AI. The process involving countless people is beyond the time scale we do not fully understand
For millions of years, humans as seeds have come close to the bottom of the food chain. Obviously, the bottom of the food chain may confuse the human brain. The human brain is wired this way, and in order to survive, we must find the risk faster than happen. The human brain in human history is in a state of being eaten more and the Lion's brain rarely appears in this situation. This explains why the human brain is dangerous with worry even in a benign condition.
There are some differences between the human brain and the sheep's brain. The human brain is getting bigger and bigger than the sheep's brain. Compared to the human brain, the sheep's brain does not have so many bumps or outlines. However, there are some differences between humans and the sheep's brain, but almost all mammals have similar brains. The brain weight of adults is approximately 1,300 to 1,400 grams and the length is approximately 15 cm. The sheep's brain is slim, and the human brain is round. Because the backbone is vertical within the human body, the brainstem has dropped to the backbone, it is level compared to the backbone of the sheep, its brain is outside. The human brain is not only bigger and heavier than the sheep's brain. It's only 140 grams compared to the human brain.