Seleksjon

Seleksjon refers to the process by which certain individuals or traits become more or less common in a population over time due to differential survival and reproduction. This is a fundamental mechanism of evolution, particularly central to Darwin's theory of natural selection. Seleksjon can occur in various forms, including natural selection, sexual selection, and artificial selection.

Natural selection operates when environmental pressures favor individuals with advantageous traits, increasing their chances of survival and reproduction. For example, in a population of moths, darker moths might be better camouflaged against a polluted environment, leading to their increased survival and reproduction compared to lighter moths.

Sexual selection is driven by competition for mates. Traits that enhance an individual's ability to attract or acquire mates, even if they don't directly aid survival, can be favored. Examples include the elaborate plumage of peacocks or the fighting abilities of male deer.

Artificial selection is a process guided by humans, where specific traits are selectively bred for in plants and animals. This is the basis for the diversity of domesticated species, from different dog breeds to agricultural crops, where humans choose individuals with desirable characteristics to reproduce.

The outcome of seleksjon is a change in the genetic makeup of a population across generations, leading to adaptation and the evolution of new species. The rate and direction of seleksjon depend on the specific selective pressures acting on the population.