translation.en: And if we study those hunter-gatherer tribes and the Neanderthal, which are very similar to early man, we find out a very curious thing about this world without technology, and this is a kind of a curve of their average age.
translation.zh: 如果我们研究这些狩猎采集部落 和非常类似于早期人类的尼安德特人， 我们会发现没有技术的世界一个非常新奇的事情， 这就是他们的平均年龄曲线。