The process of natural selection refers to one of the mechanisms of the evolution of the species of living beings proposed by Charles Darwin and Alfred Russel Wallace, from which they explained the design of nature. For example: the white fur of arctic animals that allows them to hide in the snow.
Natural selection occurs through the progressive adaptation of species to their environment. When individuals with certain traits have a higher survival rate than other members of a population, they pass on these heritable genetic traits to their offspring.
Evolution, Genes and Natural Selection
Natural selection is the central basis of all evolutionary change, being also the process through which better adapted organisms displace less adapted ones by the slow and progressive accumulation of genetic changes.
Any contribution of an individual to the next generation is recognized as biological efficiency. The biological contribution is a quantitative trait that encompasses many others, related to survival of the fittest and differential reproduction of different genotypes.
The fundamental thesis of natural selection is that traits are heritable, but nevertheless there is variability in the trait among different individuals. Thus, there is a biological adaptation to the environment, and only certain characteristics of the new features are extended to the whole population.
Each generation is in permanent evolution, and it is precisely the set of variations that occur throughout the generations that constitutes the evolutionary process.
Examples of How Natural Selection Lead to Evolution
- The evolution of medicine is based on the fact that the use of antibiotics for bacteria kills some of them, but those that survive become more resistant.
- The white fur of arctic animals, which allows them to hide in the snow.
- Camouflage of grasshoppers makes them look like leaves.
- Giraffes, of which the ones with the longest necks survived.
- The color change of a chameleon to protect itself.
- The cloning process, constantly under development but already proven in fact, could potentially interfere with natural selection.
- Brown beetles have a better chance of survival, and more offspring become frequent in the population.
- This is the case for all the species that have been disappearing, and are still disappearing.
- Cheetahs, of which the fastest survived.
- The evolution of the human being in different species, called hominids.
- The deformation of the snake’s jaw to swallow larger prey.
- The change of coloration of some moths, motivated by the industrial revolution in England. (The change in the environment was man-made).
- The waggle dance of bees.
- The insecticide resistance of some insects, evidencing the question of selection as a source of survival.
- The shape of the beak of finches changed over time, as they hardened after droughts, allowing them to eat harder seeds.
- The ability of humans to learn to speak.
- Orchids that are able to trick wasps into ‘mating’ with them.
- Non-venomous king snakes, which mimic venomous coral snakes.
- The courtship rituals of birds.