Natural Selection vs Adaptation
Evolution is a basic concept of modern biology. It explains how life has been changed over generations and how biodiversity of life occurs by means of mutations, genetic drift, and natural selection. Natural selection and adaptation are two basic concepts which are coming under Darwin’s Theory of Evolution. In Darwin’s theory, he said that all life is related and has descendants from a common ancestor. All species, therefore, can include in a vast tree of life. Natural selection is the known cause of adaptations, but the other non-adaptive causes like mutation and genetic drift are also responsible for evolution of life on earth. Darwin explained that the organisms with more favorable variations or adaptations and with higher reproduction rates could increase their chance for survival. These species pass these adaptations to future generation, and that could help to spread their adaptations throughout the entire species.
Natural Selection
Natural selection is defined as any coherent difference in fitness among phenotypically different organisms. It is the main, important concept of the origin of species and the evolutionary theory. According to Darwin’s explanation, natural selection is the driven force of evolution, but even without the process of natural selection, still evolution could occur especially by genetic drift.
The ability of survival and reproducibility of an organism is used to measure fitness of that particular organism. Heritable variation within the population, production of many offspring, and variations of fitness among the offspring are the conditions which eventually produce competition among organisms for survival and reproduction. Those who have favorable traits would survive and pass these advantageous traits to the next generation while those who do not have the favorable traits would not survive.
Adaptation
An adaptation is defined as an evolution process which enhances the fitness of a particular organism, relative to alternative character states. As Darwin had explained, Natural selection is the known cause of adaptations.
Organisms would develop their own traits to face environmental challenges in order to survive themselves by the process of adaptation. The members who developed these adaptive traits would survive in the environment and be able to pass their traits, which are responsible for these adaptations, to next generations. These adaptive traits could lead to structural, behavioral, or physiological changes in organisms.
Difference between Natural Selection and Adaptation:
- Natural selection is the only mechanism known to cause adaptation among individuals in a population.
- The driven force of evolution is Natural selection, not adaptations.
- Natural selection leads to produce adaptation among individuals in a population during the process of evolution
- Unlike natural selection, adaptations are made by traits which are known as adaptive traits. These traits would increase the fitness among individuals in a population.
- Adaptations would result in structural, behavioral, or physiological changes, in organisms. This is a direct process which is done by adaptive traits. The ultimate result is that the organism with these adaptations would be naturally selected by the process of evolution.
- Natural selection may occur at different levels like genes, individual organisms, population, and species. While adaptation mainly occurs at the gene level and eventually would become a change in the other above mentioned levels.
- Natural selection does not provide any foundation for morality or ethics in behavior of organisms, especially in humans, but adaptive traits would evolve to change especially certain behaviors among populations.