除了人类以外,世界上所有的雌性哺乳动物在生育的时候都不疼,也不需要帮忙,这就是人类进化所必须付出的代价。为什么这么说呢?原来,当非洲的森林突然消失的时候,人类的祖先不得不从树上下来,学会直立行走。直立行走解放了人类的双手,开阔了人类的视野,因此,人类逐渐进化出一个体积巨大的脑袋,用来处理各种信息,并最终进化出了智慧。 Except for humans, all the female mammals in the world do not hurt or need help at birth, and this is the price that humans have to pay to evolve. Why did you say that, when Africa’s forests suddenly disappeared, human ancestors had to come down from trees and learn to walk upright. Upright walking has liberated human hands and broadened human horizon. Therefore, human beings gradually evolve a huge brain to handle all kinds of information and eventually evolve their wisdom.