Mechanism #2: Competitive Advantage in an Environment

The background environment for the bugs is a jpeg image. Since this environment is a color image, the color of the bugs gives them a competitive advantage or disadvantage for being detected by you or other players in the competition. Bugs that you can't find easily have a competitive advantage for surviving longer and therefore a competitive advantage for producing more offspring similar in color to themselves.

This is how competitive advantage in an environment emerges in the simulation.

Mechanism #3: Selective Pressure

The competition format encourages you and other players to simulate some of the behavior of predators in the real world. Predators that gain more food survive longer and predators that do not get enough food die. So as you try to hunt as quickly as possible you and other players unintentionally generate a form of selective pressure on the population of bugs. Without realizing it all the competitors are removing easily to detect bugs from the population more often than others and leaving harder to detect bugs in the population more often than others.

This is how your actions result in selective pressure.

Outcome: Natural Selection Leading to Evolution

These three interacting mechanisms 1) inheritance and mutation, 2) competitive advantage in an environment, and 3) selective pressure together lead to an emergent phenomena: Natural Selection, which is the continual change in distribution of traits in the population to make the population better fit to survive over time. The specific outcome of every competition is never identical (the colors and distribution of bugs is always different and the environment can be set to be any background image), but the general outcome (that the bugs evolve to become better camouflaged over time) is nearly always the same.