Errr... should have been in here earlier.
Evolution is NOT:
-improvement
-intentional (evolution can never "imagine" things)
-solely mutations
Evolution is:
-variance
-survivability *of genes*
Mutation is a valuable source of variance, but not the only one. There is also recombination and horizontal gene movement. A mutation can spread because people like to "get busy" with other people. Sometimes, novel gene expressions can come from a combination of existing alleles, too.
However, survivability is the filter by which these gene combinations will live or die. All that humanity can do is change the filter ; we can not get rid of it. Proof? Can we keep a person alive whose genes can't produce hemogoblin? They die in the womb long before we can do anything about it. Or, maybe you think we can? Well, how about a person whose blood vessels simply don't develop? The brain probably doesn't even get a chance to develop, so there's no mind in there you can identify as human. How about a person whose bones don't solidify?
Specifically, I'm saying that we cannot produce a human out of any combination of genes. Instead, in order to "fix" them, we end up having to use more human gene concepts and the organism is genetically more human.
Another good point is that survivability does not require the competition to die. This is because of horizontal gene transfer. Namely, a more successful gene can also yield better reproductive rates, and thanks to the power of exponentiation, those beneficial genes can spread throughout the population.
Anyways, evolution isn't so slow that we can't observe it within our time. Actually, we as a species already have an evolved trait that did not happen way too long ago. Lactose tolerance (
Wikipedia) became a beneficial trait when humans began farming. Specifically, you can obtain more calories from a single dairy cow by consuming milk rather than simply eating the cow. (Well, the "began farming" bit is more a guess on my part based upon the fact that other Great Apes do not appear to farm, nor do they appear to drink milk.)
Another interesting mutation that is believed to have popped up rather quickly would have happened during the Black Plague (
Wikipedia). Specifically, this appeared to leave populations of humans with a genetic mutation that makes them more resistant to diseases such as HIV, small pox, and possibly the black plague. In particular, this is thought to be the case because of the "high frequency of the CCR5-Δ32 genetic defect in people of European descent." (From the Wikipedia article.)
(Oh, I just added the clarification that survivability is for the genes, not the individual. For example, an ant colony does not work by ensuring the individual survives, but rather that their genes do ; the individual will sacrifice themselves and ensure that their queen will survive to breed. That is how they increase the survivability of their genes.)