luonnonvalikoiman

Luonnonvalikoima, known in English as natural selection, is a fundamental mechanism of evolution. It describes the process by which organisms with traits better suited to their environment tend to survive and reproduce more successfully than those with less advantageous traits. Over generations, this leads to an increase in the frequency of beneficial traits within a population.

The concept was famously described by Charles Darwin and Alfred Russel Wallace. It relies on several key principles. First, there is variation within a population; individuals are not identical. Second, there is inheritance; these variations are passed down from parents to offspring. Third, there is differential survival and reproduction; not all individuals survive to reproduce, and those that do, do so with varying success. Organisms that possess traits that provide them with an advantage, such as better camouflage, resistance to disease, or more efficient foraging, are more likely to survive and pass those traits on.

Over long periods, natural selection can lead to significant changes in populations, driving adaptation and the formation of new species. It is a continuous process, constantly shaping life in response to environmental pressures. The effectiveness of natural selection depends on the presence of heritable variation and the selective pressures exerted by the environment. It is not a directed or purposeful process, but rather an outcome of the interaction between organisms and their surroundings.