Evolutionary pressure

Selection pressure indicates the action ( the " pressure") of a selection factor for a population of organisms. Selection factors are environmental factors that have an impact on the survival of a population in a particular environment. Especially in the English language as a synonym (but not entirely correctly), the term evolutionary pressure for it is (Eng. evolutionary pressure ) is used, which is to indicate that through the process of selecting a result, the evolution in a population takes place.

Already Charles Darwin realized that all beings are subject to selection. Have better adapted individuals, statistically, adapted a higher reproductive success than worse. This eventually leads to an adjustment of population to the effective environmental factors.

It differs mainly three types of selection pressure:

• Stabilizing selection pressure
• Transforming ( shifting, changing ) selection pressure
• Disruptive ( aufspaltender ) selection pressure

A good example are the wingless birds on the Kerguelen. Usually wingless flies have no good chance of survival, and if they survive, they have significantly fewer offspring than their winged counterparts. On the other hand, Kerguelen, it is vice versa. On this situated between South Africa and the Antarctic archipelago constantly are strong storms that blow away the winged flying on the sea. Here wingless flies have prevailed. The winged individuals were subject to the pressure of the selection factor " storm".

• Evolution