Quote:
Originally Posted by tore
Natural selection is a consequence of life as we know it. You can't turn it off. What changes is stuff like the strength and direction of selection (is it better to have a smaller or larger beak? Better to birth females or males?). Random killings from natural disasters is part what's called genetic drift and it generally does have an effect (it changes the overall genetic makeup (allelic frequencies) of the human population ever so slightly), but the effect is smaller the larger the population is.
As for what evolution favours, you should remember that fitness which is what is selected for is measured by how much one's able to perpetuate one's genes. If society is made up in a way that makes asocial people and criminals have overall less fitness (have fewer children) than their counter parts, then that could translate to a selection on a genetic level with important effect on our common genetic makeup over the course of our relatively recent history. You could arguably call that natural selection because it is the environment of the societies which dictates the consequence (making it a natural consequence in that environment), but it's not consciously selected for by a great manipulator. Environment is important, so for our example, let's say in pre-society, the traits which more often create asocials and criminals had a generally more positive effect on fitness.
Ecologists often say simply that evolution is simply a change in allele (varieties of genes) frequencies over the course of generations, for example that the relative frequency of the allele which codes for blue eyes is less in the new generation compared to the parent generation. Going by that definition, it would be hard to argue that mankind does not evolve .. or is f.ex the North American population pretty much similar to what it was like 100 years ago? |
Indeed. I would also like to add that human evolution does not need to affect only our physical bodies. Our brains didn't just magically pop into existence. They evolved due to the fact that we were using them more (creation of fire, tools, agriculture, and even group interactions since they require more brain power than being solitary). And we are still finding ever more complicated and difficult things to make our brains deal with, so our brains are still evolving and will always be evolving.