new drkitten said:
Re-read Gould and Dawkins. Evolution doesn't occur as a gradual uniform process; it usually happens in fits and spurts when there's competition for resources and niches. We're almost certainly in one of the in-between times, exactly because competition for resources has dropped so far. We're therefore almost certainly not experiencing much evolution at the moment. This will remain the case until we have a shock to the system and nature gets a chance to sort the wheat from the chaff, as it were.
Umm, I haven't read upcoming posts yet, but had to jump in here before I did. So if you've recanted this idea later, I apologise now.
You've misunderstood Dawkins, if that's what you've gleaned from his books. Gould too, for that matter. Punctuated Equilibrium is indeed a process of evolution, in that single events in nature can dramatically alter what's called 'genetic drift'. On its own, genetic drift can still change a species through purely random change. It is the principle behind 'Gradualism', which is what occurs in some way in between PE.
Some people believe that PE is always occuring on some scale, which is another acceptable way of seeing it.
Evolution cannot 'not' happen. Mere mutations ensure that we are different to our parents. The question is, how genetically different does one have to be to be considered a new species? THAT is a good argument, but for another thread.
Genetic Drift experiences bias when selection pressures are added, of which so-called 'natural selection' is one. It is by far not the only one, nor in present views the most important. Humans experience other selection pressures which dictate the number of offspring born in one gene pool. This, when combined with an analysis of movements between gene pools, makes it hard to envision how human populations can change. But it is still clear that we DO change.
In my view, selection pressures are more social in humans than functional or geographical. Hence it is our behaviours which will determine how many offspring we have. Any physiologically linked traits will probably go along for the ride.
There may be subtle sexually selective traits, such as body shape or facial features, but I don't see these translating directly into more offspring. Hell, to be crude, I see a lot of ugly people having large broods of sproglings, so I don't feel that it is an immediate selective pressure.
Athon
