Light will be thrown on the origin of man and his history.

Man is descended from a hairy, tailed quadruped, probably arboreal in its habits.

Man selects only for his own good: Nature only for that of the being which she tends.

There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery.

We cannot fathom the marvelous complexity of an organic being; but on the hypothesis here advanced this complexity is much increased. Each living creature must be looked at as a microcosm--a little universe, formed of a host of self-propagating organisms, inconceivably minute and as numerous as the stars in heaven.

I think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct. The forms which stand in closest competition with those undergoing modification and improvement will naturally suffer most.