and get put together in a coherent story. From this perspective,

然后这些事件整合成一个连贯完整的故事从这个观点来看
dreams serve no adaptive function at all but rather they're epiphenomena.

梦完全不具备适应功能相反它们是副现象
They are the byproducts of another system.

它们是另外一个系统的副产物
Final topic is laughter and this is a true mystery.

最后一个主题是笑这真的是个不解之谜
I got interested in this--well,

我对此很感兴趣
I got interested in this as a developmental psychologist

作为一个观察我自己孩子笑的发展心理学家
watching my own children laugh

我对此很感兴趣
and trying to figure out what it is that made them laugh.

试图找出什么令他们笑的
This is my son, Zachary, pretty young

这是我儿子扎卡里还很小
but this is not the youngest record of laughing. I found this on the web.

但这不是笑声记录中最年轻的我在网上发现这个
It's a huge puzzle. From an evolutionary point of view,

真是个大谜团从进化的观点来看
people's pursuit of sex and food and drink and sleep

人类追求性食物水和睡眠