Natural selection is an important mechanism of evolution proposed by Darwin. It ensures that the organisms best suited to live in a given environment are selected.
→ Who proposed the theory of natural selection?
The theory of natural selection was proposed by Charles Darwin , a leading naturalist who changed our understanding of how species change over time. According to this naturalist, there is a constant struggle for survival, and natural selection acts in this process. Therefore, the fittest organism would be able to survive and would have more chances to reproduce, thus preserving the useful variations for each species. It is worth noting, however, that, despite knowing the genes and the mechanisms of heredity, Charles Darwin did not know them, which left a gap in his work, which was later filled .
→ How does natural selection occur?
For natural selection to occur, some factors are necessary: variability between individuals, differentiated reproduction and heredity.
- Variability between individuals: Organisms of the same species need to have variations in their characteristics. Without these individual differences, the selection could not function.
Differentiated reproduction: The organisms best adapted to a region reproduce more frequently than the others. Disadvantageous traits can lead individuals to death even before their reproduction.
- Heredity : Advantageous traits are passed on to offspring, increasing their frequency in a population. This trait, if it continues to grant evolutionary advantage, will be passed on to several generations until the disadvantageous trait becomes rare.
Imagine that there is a population of white and black mammals ( variability ) and that they live in a snowy region. Black mammals are easily spotted by predators, which is not the case with white mammals, which are able to camouflage themselves in the snow. As a result, there is less predation on white individuals, who are more likely to reach reproductive age ( differentiated reproduction ). At the time of reproduction, advantageous traits are passed on by genes ( heredity ) to offspring. Over time, the number of better-adapted white mammals exceeds the number of black mammals.