Nintentacle said:
We still have no observable evidence.
|
We do, we're just limited on how large a scale we can watch it happen. If it's something like a virus or bacteria that has an incredibly short life cycle, we can see it evolve rapidly (providing the environment encourages it, of course). Why do you think there is such a strong push to limit our use of antibiotics? Because out excessive use of them is leading to the rapid evolution of some types of bacteria, resulting in 'super bacteria' (ones that are immune to antibiotics).
It's perfectly understandable for some people to believe evolution hasn't happend, but there is no deny that it can happen. That, combined with how closely nit many species are (as well as the various types of the same animal, each specialized to their environment) is why it's so widely believed.
The best example is the 'tall world' situation. Two tall parents are considerably more likely to have a tall child than two short parents. It's not a universal outcome (since there are other favors involved), but the probability of the child being tall is considerably higher for the former than the latter. So now that we have established a human's physiology can be directly influence by the passing on of genes, let's expand it to a hypothetical situation.
Let's say we live in a world where being tall is a huge survival advantage, due to [x] circumstances. This would mean tall people would generally be more sought after for mating than short people, and would likewise have the potential to survive in this world longer (thus have more opportunities to have kids). This would mean that, over the period of several generations, the humans race would get continually taller. That is, in essence, evolution.
The issue in observing it in things like humans is that we have long generations gaps (generally about 25 years). In the situation i explained above, where we have a direct environment challenge and a pre-existing gene to combat it, the process would still take hundreds of years for it to drastically affect our appearance. Shit's slow yo o/