Just as the individual has a definite length of life, so have species a limited duration. The progress and transition of the world, Darwin declares, will see the extinction of certain variants of human life. (Volume 11, Harvard Classics)
Darwin first outlines his theory of natural selection, Sept. 5. 1857.

Introductory Note: Charles Darwin

Former President of Harvard University Charles W. Eliot wrote in his introduction to the Harvard Classics, "In my opinion, a five-foot shelf would hold books enough to give a liberal education to any one who would read them with devotion, even if he could spare but fifteen minutes a day for reading." Here you are, you can easily listen to his entire 15-minutes-a-day study guide while commuting to and from work (most of us spend far more than 15 minutes a day commuting each day), doing mundane work in the office, washing dishes at home, or doing most of the things day in and day out. It is so easy, so entertaining, and so educational that they can be listened to again and again, until they permeate into our own thinking and into our characters. Perhaps, in one year's time, you will become someone you barely recognize, all for the better. Who knows?-- Rich E Book