What is natural selection?

Natural selection is a fundamental mechanism of evolution that explains how certain traits become more common in a population over time. This process occurs because organisms with characteristics that are better adapted to their environment tend to survive longer and reproduce more than those that are not as well adapted. As a result, advantageous traits are passed on to the next generation, leading to a gradual change in the population's characteristics.

In essence, natural selection acts on existing variations within a population, favoring those that confer a survival or reproductive advantage. Over many generations, this can lead to evolutionary changes and adaptations that enhance the organisms' ability to thrive in their particular environment.

While the other options touch on aspects of evolutionary biology, they do not precisely define natural selection. For example, the creation of new species is more accurately described by the process of speciation rather than natural selection directly. Likewise, although adaptation to climate changes is a result of natural selection, it is not the entirety of the process. The change in gene frequencies over time is a broader concept that includes more than just natural selection, encompassing genetic drift and gene flow as well.