Charles Darwin developed the theory of how living things develop from simpler organisms over long periods of time.

VOA: special.2009.02.25

Now, we're going to go back to Roger Ibbotson at the School of Management. He did some path breaking work in terms of describing capital markets returns over reasonably long periods of time.

先讲回到管理学院的罗格·伊博森,所进行的开创性研究,描述了在相当长的时期内,资本市场的收益情况

耶鲁公开课 - 金融市场课程节选

Over long periods of time, these small changes result in the creation of new species.

VOA: special.2009.12.01

He thought that this was evidence that the bottom of the ocean had been lifted up by powerful geological forces over long periods of time.

VOA: special.2009.02.25