As we'll talk about later in the class, the biodiversity has shrunk so what used to be hundreds of varieties of corn is now just a few.

像我们后面所要提到的,玉米种群的生物多样性已经从曾经的,几百种减少到了现在的几种

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Finally, behaviorists believed there were no interesting differences across species.

最后，行为主义者认为,生物种群之间并不存在太大的差别。

耶鲁公开课 - 心理学导论课程节选