尽管达尔文的书名叫人类由来，但他对人类起源却鲜有论及。

Despite his book's title, Darwin had little to say about human origins.

youdao

这是人类魄力与进取的特殊泉源，但同时也是，抵制他人进犯的由来。

It is the unique source of human assertiveness and aggressiveness as well as the source of resistance to the aggression of others.

youdao

为了某些可取的特性，人类选择性地繁育野生植物或动物物种，这一开始是一个断断续续的反复试验过程，驱动它的是由来已久的紧迫之事——饥饿。

Selectively breeding a wild plant or animal species for certain desirable traits began as a fitful process of trial and error motivated by that age-old imperative: hunger.

youdao

Here it is not just the venerability of slavery, how old it is, but it's the idea that it has been crucial to the development of all great civilizations.

不仅仅讨论奴隶制的庄严性与历史由来,更是它曾经对人类文明的发展,起过至关重要的作用

耶鲁公开课 - 美国内战与重建课程节选