Professor Steve Jones (geneticist) argues that human evolution is almost at an end - at least in the developed world.

http://www.timesonline.co.uk/tol/news/uk/science/article4894696.ece

He gives three reasons for this:

(1) the weakening of natural selection owing to 98% of children surviving to 20yrs of age
(2) the shortage of older fathers
(3) all populations are becoming connected and the opportunity for random change is decreasing

"Time is what prevents everything from happening at once" - John Wheeler