So we've argued that human sexuality has essentially evolved, until agriculture, as a way of establishing and maintaining the complex, flexible social systems, networks, that our ancestors were very good at, and that's why our species has survived so well.
我们的论点是，人类的性行为 直到农业社会前逐渐形成了 一种建立和维持复杂而灵活的 社会系统、人际关系网的方式。 这种方式我们的祖先很在行， 这也是为什么我们的种族生存得很好。