I'm guessing that our history class is (in the next couple of days) going to break out into a huge debate about evolution. In order to quell the usual outburst of completely illogical and factually incorrect arguments that will come up, I want to learn a few basic things about chemistry, mainly adaptation...so at least we have some facts to argue around. 1. When a big creature like a human adapts, what causes that? Would I be correct in saying "The brain sees the room for change, and sends chemical messages to the body to develop different." Also, for changes that might be made at birth, does an organism change its own DNA, thus automatically changing its child's? Or, does it keep its own the way it is, then change the kid's in the time when it's born? I'm assuming that adaptation occurs because of DNA changes, if thats wrong then please inform me. 2. Also, we have of course witnessed small evolution, like those butterflies changing colors in europe. Assuming that evolution would occur because of chemical signals, would it be impossible for a single-cell organism to adapt/evolve? 3. Have biologists ever (in a scientific environment, of course) witnessed a single-cell organism change into a multi-cell organism? 4. Does the theory of a very complex organism like an ape being formed from a single-cell organism have any gaping holes as for as biology is concerned? 5. If a complex organism like an ape was formed from a single cell, shouldn't we have fossils of those "in between" stages?