* Variation, which arises through mutation, exists within and between populations for every trait.
* More individuals are born into a population than can survive (usually because of the scarcity of resources).
* Traits are passed down from parents to their offspring.
* Individuals most fit to survive in their environment generally do (Natural Selection).
Of course, there's a lot more which is easier to absorb once you have the basics. Link
From the Upcoming ueue, submitted by Geeksaresexy.
*so confused*
I was brought up in a Christian home, where we learned about dinosaurs. My parents didn't try to tell me that dinosaurs all lived during the time of Moses, and they didn't tell me that I had to accept the story of creation as 100% fact. I think if more Christians were raised this way, they wouldn't have such a conflict with the science of evolution, and they wouldn't advance preposterous hypotheses to make the facts fit their conceptions.
We didn't. We were never monkeys, we did not evolve from monkeys, the theory of evolution does not say we evolved from monkeys, and it would be plainly absurd to believe we did. Unfortunately, too many creationists prefer to lie to you (in direct violation of a certain Commandment, I believe) and tell you this is what evolution says in order to "debunk" it. This lie is often followed up with the question "Then why are there still monkeys?" It's like saying that Christianity can't be true because Christianity says that the earth is flat and we know that's obviously wrong. (Christianity does not say that, of course, which is exactly the point. It would be extremely disingenuous, or at least ignorant, to make such an argument.)
Evolution says that humans and apes evolved from a common ancestor, which was neither human nor ape. It's essential to understand that in order not to sound foolish. Next time the argument comes up, you'll be better prepared to state your case without being dismissed as one who knows nothing about what he's arguing against.
Evolution takes a very long time - and it needs pressures to make it happen - without a good reason to select one model over another there will be very little change over millions of years. Crocodiles, for example, are a damned good fit to their niche - so they haven't changed.
Early humans were a less good fit - we needed to walk more upright to conserve energy (waddling like a chimp is inefficient, walking on two legs is very efficient), we needed larger brains (ours are measureably larger than proto-human's) and so on.
Were you expecting Aunty Flo to suddenly grow longer arms so she didn't keep asking you to get things off the top shelf? IF, given a very large number of generations an Aunty Flo had a better chance of survival with longer arms than without then yes, all other things being equal, longer arms might develop. One of the issues is that all other things /aren't/ equal - there are so many competing pressures that change is generaly slow and very hard to predict.
It is sad, but until more faith leaders come to understand that evolution does not disprove their religion, we will continue to have this disconnect. I think many religious organizations are moving in the right direction, but we still have some major stumbling blocks.
Evolution is real, and it happens.