Two hundred years ago the most important human to walk the planet thus far was born into a comfortable middle-class existence in leafy Shropshire. By the time of his death, 73 years later, he had completely reshaped our understanding of life on this planet and had laid down the bedrock upon which all modern biological science is based.
If you claim to have an interest in anything vaguely biological, from cutting edge oncology to the finer points of redpoll taxonomy, you really should have read On the Origin of Species and The Decent of Man. The majority of Darwin's written works are available absolutely free of charge here. I would, however, suggest you invest in physical copies of the aforementioned masterpieces as, in addition to being beautiful things in their own right, they also happen to be precisely the correct dimensions and heft for beating door-knocking evangelical religious types over the head with (my personal favourite edition in this regard is the 1928 Everyman's Library version of On the Origin of Species [the one with the Jurassic fossil on the dust-cover] although I daresay the cracking new Penguin anniversary edition [complete with Damien Hurst cover] would prove equally efficient at rendering Jehovah's Witnesses unconscious).
"...above all, Darwin has shown us that we are not apart from the natural world, we do not have dominion over it, we are subject to it's laws and processes as are all other animals on earth to which, indeed, we are related." David Attenborough, Tree of Life. Or,... to put it another way, Darwin's works prove you are just another animal, so stop thinking you are something special and stop believing that some fantastical deity will appear and save your arse in this, or the next, world; take some responsibility and start working towards ensuring this planet is not utterly f*cked during the period of time you spend on it.
PS. For the truly lazy, attention span deficient, members of generation Facebook, gentle little introductions to the great man's work and its consequences are presently being aired by the BBC, see here for details.
PPS. Finally, for information on the sterling work being undertaken in the name of Darwin see here.