What is Evolution?
Uploaded by Gotskillz on Jul 05, 2004
Evolution is defined as genetically based change from generation to generation. IF and ONLY if you look exactly the same as both your parents and they look exactly the same as your grandparents and so on back to the beginning of life (however you define that beginning) can you say that evolution has not occurred.
Since I assume you are an organism born on this planet, and that you are a human being, rather than some clonal organism (one that reproduces by budding or similar method), I assume you do not look exactly like both your parents and that they do not look exactly like their parents, and that the differences are, at least in part, genetically based. Therefore, within your own family, evolution has occurred. You have seen evolution. Evolution is a fact, not a theory.
How long evolution has occurred, under what circumstances, and what drives it are theories. Evolution is not the theory, HOW life has been shaped by evolution is the theory. When a scientist says "the theory of evolution", it's not the "theory that evolution occurred," it's the "theory of how evolution occurred" that's being spoken of.
Even so, a scientific theory is a bit different than "I think the moon is made of green cheese." A scientific theory must be 1) falsifiable and 2) not disproved after some investigation.
Falsifiability means that you can disprove it without resorting to supernatural phenomenon. Show me a way to disprove that some god (any god) created the world, that could be done through natural investigation, and I'll say it meets one of the criteria. I haven't seen such a way even offered yet.
So far, the theory evolution by means of natural selection (which was Charles Darwin's theory) has been shown to be the best explanation for the path evolution has taken life. The hypotheses ("sub-theories") of the exact nature of how natural selection works are constantly being modified as we learn more and more about our world. Those hypotheses are constantly challenged and should be (that's how science learns more!). And much of what Darwin and Wallace wrote about in their early work has been found to be incorrect, but the basic premise that evolution occurs through natural selection has not been disproved.
The theory of natural selection says that organisms which do better in a particular environment will pass that ability to do better on to their offspring, and that those...