Ok here is my first question. I understand the change in species which plants and dogs are usually given as the example. Why haven't humans observed a new species emerge that did not exist before? I understand that evolution talks about a process that exists over millions of years, but does that mean all life evolves at the same time?
Actually, we have observed new species evolving, but only with very simple microorganisms with life cycles that only last a few seconds or minutes.
Evolution takes time. You might as well ask "why can't i watch the wind
sculpting new rocks?" Well, you can, but its not going to look like anything in your own life span.
Second question. I understand changes within a species where certain traits become more dominate than others. What I don't understand is where all the different species come from and how they got there? I don't see how we got from [FONT=Arial]primordial ooze to the different life forms that have inhabited the Earth. How did we go from ooze to dinosaurs, birds, cats, dogs, reptiles and you and I?
Maybe I should stay out of this since I'm just an aspie whose read a lot of books, but the simple answer to that question is entropy. Genetic coding is not perfect. Things fall apart and break down. 99.9 percent of the time a mutation is not beneficial and the organism that has it dies or fails to reproduce or at least suffers increased stress over it. But every now and then, a mutation occurs which is beneficial and then over time, that mutation spreads to larger populations. Whats hard to wrap ones mind around is how a bazillion tiny changes can lead to such large apparent changes. The important thing to remember is that essentially all evolution
over the very short term is a minor change in a species. Tiny tiny tiny little
baby steps, which add up over geological time to increasingly larger differences.
Maybe it is the length of time. I don't understand how fossils and other evidence leads so many to be so sure about the theory. If it is something we truly can't grasp and something we will never be able to verify, why are we so certain we are right? I see many people speak with more certainty about evolution than they do about current sciences. The evidence just does not seem to be there to support the theory to my non scientific mind.
Well, we can grasp it, its a matter of removing yourself from human scales and human time frame. Just imagine living for a billion years. Yes, thats hard to picture, but thats the perspective that we are looking for.
The evidence is there and it is overwhelming. However, what that evidence shows is that evolution does happen,
but not any kind of track record for the exact particulars of how it happened.
There are new theories emerging all the time to explain the evidence we have, and new evidence is being found constantly. For instance, some scientists now think that there is not just one evolutionary tree, but several, and that many different forms of simple life arose randomly from the same conditions. Its also now being shown that normal evolution creeps along very slowly, because species evolve to fill ecological niches. But if an ecology is shocked and there are mass die offs, evolutionary forces speed up to thousands of times faster than the normal rate.
(Which is one reason why human stupidity regarding ecology is such a bad idea- we are creating a situation ripe to breed the critters which will destroy us, IE we have become the new ecological niche and we have shocked the ecosystem as bad as a meteor hit.)
