I am an archaeologist and I have over ten years of training in prehistory.
Fact: Molecular science has shown that human beings and two of the African great apes - the chimpanzee and the bonobo - share a common ancestor that lived 5 million years ago.
Fact: To find a common ancestor for mankind and all of the great apes, including the orang and gorilla, you have to go back 13 million years.
Fact: The timeline of evolution has been compressed since the 1960s due to advances in molecular science.
Now, past these facts we now have growing bodies of evidence about when human beings started to look human. However, human-looking doesn't mean cognitive thinking, etc., are in place yet. There is a huge body of growing evidence that allows us to reasonably argue - not merely suggest - that we evolved in Africa from a common ancestor about 2 and a half million years ago.
The question isn't "did we evolve?" The question is when did we evolve, and under what circumstances, and why. Working out the details is what some people confuse as theory. The details are facts that have to be shuffled around as new evidence emerges. The fact that we have new evidence emerging all the time is
encouraging - not something to be afraid of, or something to be used as an excuse not to teach evolution to children.
The analogy I love the most: if someone dressed up an early human ancestor, say
Homo rudolfensis (named after a site near Lake Rudolf in Kenya), in a suit and a tie and sent him down Main Street, he'd probably scare the children but not necessarily the horses, and he'd be
recognizably human. And he died out over two million years ago, to be replaced by
Homo erectus (Pryor 2004).
The point I'm trying to make is this: human evolution is messy, difficult to understand, and absolutely full of factual evidence. This isn't a good enough reason to say that children should be taught that evolution is just another theory like any other, alongside other, more easily digestable theories - such as the existence of a creator of the universe.
My reasoning can be summed up by an anonymous post found on the TalkOrigins.org site in 2003:
Evolution matters because science matters, and too many people (including some presidents) are willing to believe that science is something you can pick and choose from, with "good" science being anything that supports your own views and "bad" science being anything that doesn't. Physicists are great guys because they say nothing to offend us, biologists are mad scientists leading us down the path to perdition with their genetic meddling, evolutionists are self-delusional fools, and anyone studying environmental science is a left-wing tree-hugging extremist whose sole goal is to destroy the American economy and lead us to one-world government. If scientists in a given discipline argue about any conclusion, whoever says what you want to hear is the right one. Too many people can't accept that although scientists are not perfect, and do make mistakes (sometimes whoppers), science isn't something you can pick through like a buffet, accepting only what is to your "taste" and designating the rest inedible. If people feel free to reject the science of evolution, they feel free to reject any science on no better grounds. Whether my students accept evolution may have little direct effect on my future. Whether they understand biology, ecology, environmental geology (water is a big issue in my community), and other subjects and can make informed decisions regarding scientific issues does matter. If they feel free to reject evolution as part of a "buffet" approach to science, their other choices will be no better informed.