Thread: How Evolution Happens

Originally Posted by zyna

I couldn't agree more with you. Many people think they've understood the theory of evolution, because essentially it's pretty simple, but somehow they don't seem to understand it's consequences. And most people forget one important factor in evolution: not mutation or selection, but chance. i.e. an earthquake or a volcanic eruption don't ask about adaptation, they simply kill everything within their reach. And the individuals that survive, mostly by pure chance, will form the new population, in which the genes can be distributed totally different compared to the original population. And those genes will be passed on to the next generation.

That's actually a really bad way of putting it - it's not by pure chance.

Natural selection doesn't work on chance. It works on the basis of survival of the fittest. Words like 'random' and 'chance' really shouldn't be used in conjunction with an explanation of natural selection because natural selection is anything but random, it's 'guided' towards the strong surviving and the weak dying. The only random part about any of it is the mutation in the genes to create variation.

It's not a bad way of putting it, because I wasn't referring to natural selection. I didn't disagree with you, I simply noted another fact that many people forget. I know this won't persuade you into "believing" me, but I'm a biology student and many of my professors cannot stress the factor of chance enough, because it's something that many people tend to forget, when they're teaching the theory of evolution. This does not contradict the mechanisms of natural selection, it adds an aspect to it, that cannot be predicted.

Random mutations, change of environment and natural selection are factors of evolution, but so is chance. As I said, chance is another important factor. There may be organisms that are perfectly adapted to their environment, but they still wouldn't survive a volcanic eruption or a meteor hitting the earth. And chance in the form of natural 'catastrophes' has contributed to the biodiversity that we know today.
Natural selection does not lead towards the strong surviving, but the best adapted surviving.