WHAT IS THE RELATIONSHIP BETWEEN ADAPTATION AND NATURAL SELECTION? - BIOLOGY - 2025

The relationship between adaptation and natural selection is based on the fact that the species that best adapt to a given environment survive, reproduce and are therefore naturally selected. On the contrary, those that do not adapt die out.

In 1859, Charles Darwin presented his theory of the evolution of species by natural selection in the book The Origin of Species. In this theory, Darwin talks about the relationship between adaptation and natural selection, and defines both phenomena as fundamental elements for life as it was known at that time.

Charles Darwin

This theory was innovative for many reasons. One of the most relevant is that it contradicted the notion that the world was a predetermined creation, carried out by a supernatural entity that had designed each structure the way it is seen.

This novel way of thinking contradicted even the very beliefs of Darwin, who was a man who considered himself a Christian.

Darwin waited 20 years before publishing his findings, while trying to gather more information, and while remaining in conflict with his own convictions.

After years of observing different specimens of nature in their different habitats, Darwin determined that there was a greater abundance of those individuals that were better adapted to the conditions of the place. These organisms were strong, young, and lived longer.

Today there are countless examples of organisms and species that have developed very specific characteristics that allow them to function favorably, adapt to the environment and, therefore, have a better chance of survival.

Adaptation and natural selection can be considered cause and effect within the evolutionary process: those individuals that adapt best will be the ones chosen to live and develop successfully in a given ecosystem.

Having clarity on both concepts (adaptation and natural selection) will allow us to understand in a better way the intimate relationship that exists between them. Therefore, the most relevant characteristics of both notions will be detailed below.

Adaptation

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Adaptation refers to those changes and mutations in the genetic field that certain species adopt in order to survive in an environment with specific characteristics. These structural changes pass to the following generations, that is, they are hereditary.

Similar organisms can compete in adaptation, and the one that manages to get the best out of the environment that surrounds it is the one that will be better adapted.

The environment plays a fundamental role in the adaptation of organisms; In most cases, adaptation is developed precisely by a variation in the ecosystem in which certain individuals inhabit.

The environment will dictate the conditions that are necessary for an individual or species to develop successfully and achieve survival.

Physical and behavioral changes

Example of morphological adaptation

The adaptation process can refer to physical aspects, structural elements of an organism. And it can also refer to aspects related to her behavior in the circumstances that surround her.

If the characteristics of the organisms are detailed, in some cases elements can be observed that were once the result of an adaptation, but that currently do not fulfill an important or even useful function, because the conditions have changed.

These elements are named vestigial organs; for example, vestigial human organs are the coccyx, appendix, and male nipples.

In the case of animals, vestigial structures can also be found: traces of the hind legs in whales, or eyes in animals that live underground in complete darkness.

These structures correspond to elements of their predecessors, which are not necessary today.

Adaptation and new species

Generally, adaptation generates changes in a species, but it maintains the essence of its nature.

However, there are cases in which a completely new species has been generated from an adaptation, caused by environmental aspects, by isolation from individuals, among other reasons.

Natural selection

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The process of natural selection allows only the fittest individuals to survive and reproduce.

The theory of natural selection indicates that those organisms with more functional characteristics in relation to their environment, have a greater chance of reproducing and surviving in said environment, instead of organisms that lack these abilities.

As a consequence of this differentiation, the organisms with the most unfavorable characteristics reproduce less and, eventually, may cease to exist, giving way to those that perform better in a given habitat.

Better performance, longer permanence

Given that there is differentiation between organisms, it will be possible to show which of them has the characteristics that allow it greater capacity for functioning and development in an environment with specific peculiarities.

It is important to highlight that natural selection is associated with specific circumstances, related to a specific time and place.

All the variations that are generated and that are of benefit to the species, will become part of the individual, and will even be inherited to the following generations, if they are vital for the survival of said species.

Natural selection should not be seen as a force acting from the outside; It is a phenomenon that is generated when there is a preponderance of one organism over another given its superior reproductive characteristics.

It can be said that natural selection has occurred when the adaptations made by organisms are consistent in time, and do not occur as a consequence of chance, but persist in large populations and for several generations.

Relationship between adaptation and natural selection

As can be deduced from the previous concepts, natural selection and adaptation are closely related notions.

The organisms that have managed to vary their physical structure or their behavior to be able to function better in a specific environment (that is, those that have adapted), are the ones that will be able to continue to develop in that environment, they will be able to continue reproducing and, therefore, they will be able to continue to exist.

Likewise, organisms that failed to adapt to their environments will not be able to reproduce and will therefore end up naturally disappearing.

That is, adaptation corresponds to variations in individuals or species, and natural selection refers to the best chance of survival for those individuals or species that managed to adapt.

So, adaptations are those qualities that have been naturally selected and that have allowed a species to remain in one place, to be able to reproduce and to be able to produce several generations of individuals.

Adapted individuals are naturally chosen to remain in such a place.

References

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