unnatural selection

An occurence of natural selection that has been initiated by humans. For example, in the areas around highways, there is selection for butterflies that fly over 15 feet above ground level, and selection against those that fly below this level - those that do tend to get killed by traffic before they have the chance to reproduce. A more famous example is the pepper moth in England. There is a light and a dark variety. The light variety used to be more numerous, but with the industrial revolution, the black moths were now more camoflaged on the soot-darkened trees, and the white ones stood out, which made them more vulnerable to predators.

An unusual genetic engineering simulation video game from Maxis (not entirely unlike their similarly-nebulous but more immediately-grokkable SimLife) where you manipulate variations in speed, strength, stamina, vision and fighting, eating and mating behaviors in artificial life-forms known as Theroids, hand-tuning mutation rates and directing the successful generations against their less-successful brethren.

Like many simulations, very abstract as a 'game', but supportive of hundreds of hours of high-level tinkering, figuring out how to work the engine of these simple creatures.