Darwin's theory

For Darwin's 200th birthday, The Economist had a good article about what his theory was and what others thought/think of it. It is well worth the read, here.
The religious implications for the time were quite earth shaking.

A little extract:
"The idea of evolution by natural selection is not hard to grasp. It just requires connecting some uncontentious propositions. These are that organisms vary from one another, even within a species, and that new variation can arise from time to time; that some of this variation is passed from parent to offspring; and that more individuals are born than can exist in the available space (or be sustained by the available resources). The consequence is what Darwin described in his book as a “struggle for existence”. The weakest are eliminated in this struggle. The fit survive. The survivors pass on their traits to their offspring. Over enough time, this differential transmission of characters will lead to the formation of a new species.
But what was missing was the mechanism.
Malthus argued that natural populations grow at an exponential rate, whereas the increase in food supply is linear. In other words, more individuals are born than can possibly survive, [hence] winners and losers."

Darwin also stated that living creatures (humans included) have 2 purposes: survive and reproduce, the latter being of higher priority.