Deterministic within the stochastic...selection that is

The answers keep coming in for my query about "what is evolution?" RPM took me to task for basically answering "what is selection" with my initial response. This is a good criticism...honestly, I wanted to focus on selection because I think random genetic drift confuses many people, and it quickly turns into a black box incantation that explains everything and nothing. But here's another point of interest: selection is stochastic as well! That is, selection favors fitness, and fitness tends to exhibit particular characteristics in particular environments (e.g., extremely fast vertebrate aquatic creatures seem to converge upon similar forms because of the constraints of physics), but at least in the short term there are often many solutions to the same problem. You want an example? High altitude peoples, different genetic and physiological responses. Now, I did say "short term," because I am to understand that the Tibetans, for example, seem ...