Quote Originally Posted by Viking View Post
Natural selection does not operate with reasons, so that is a moot point. Random mutations and probabilities are what that matters. If some individual is carrying a mutated gene that gives him greater intelligence, then that is a potential advantage. So if he breed, the offspring of his that also carry the genes will have a greater chance of survival, provided that they are otherwise fit. As generations passes, this gene has a potential to become more widespread throughout the population since its carriers are more clever than the individuals that lack the gene. By pure chance, or because of genetical differences between the populations already present, this process could have different paces or take different routes in the two populations. I think the random element makes the evolution unpredictable.
No not completely. The enviroment is the deciding factor of what mutations are more profitable. For example most larger animals evolve to smaller animals when living in a small closed area for example an Island or in dense forrested areas. (Take the Homo floresiensis, or compare a giraffe with an okapi.)
While evolution happens random it usually alwas is a way to adapt to the enviroment. Hence the enviroment does indirectly help determing what possible charasteristics evolve and in what way. Now with intelligence it is just not that easy to determine and expect.