Introduction to Natural Selection

Understanding Natural Selection

Natural selection is the process by which certain traits become more common in a population due to their effect on an organism’s ability to survive and reproduce.
It’s a key mechanism of evolution, first articulated by Charles Darwin.
Natural selection can lead to significant changes in a species over vast periods of time.
Essential components of natural selection are: variation, inheritance, selection and time.

The process begins with variation in traits within a population of organisms. These variations can be due to differences in genes (mutations) or environmental factors.
Next, happens inheritance, where traits are passed on to offspring from parents.
Selection occurs as some individuals have traits that give them an advantage in the battle for resources and reproduction. This results in the ‘survival of the fittest’.
Those with advantageous traits survive to reproduce more effectively, so these traits become more common over time while detrimental traits tend to be ‘weeded out’.
Natural selection operates over long period of time depending on the species and the environmental conditions.

Natural selection can lead to adaptation, where species become more suited to their environment, enhancing chances of survival.
It can also result in speciation, the emergence of new species. This typically happens when populations of the same species become separated, expose to different selective pressures and evolve differently.
However, if the environment changes rapidly and species can’t adapt, it may lead to extinction.

Unlike artificial selection, natural selection is not guided by any conscious entity, but by the interactions of organisms with their environment.
Natural selection promotes traits that ensure survival and reproduction irrespective of human desires. Whereas, artificial selection focuses on traits which humans find desirable.
Natural selection happens over a much longer timescale than artificial selection due to the lack of controlled breeding.
Natural selection has the potential to maintain and increase genetic diversity, while artificial selection can lead to reduced genetic diversity due to selective breeding.