Natural Selection

Definition

Natural selection is the gradual process by which biological entities adapt to their environment and become better suited to survive and reproduce. It is the core mechanism of evolution, where favorable traits are preserved and passed on to future generations, while unfavorable traits are eliminated.

5 Must Know Facts For Your Next Test

1. Natural selection acts on the genetic variations within a population, favoring individuals with traits that are better suited to the environment.
2. Traits that confer a survival or reproductive advantage are more likely to be passed on to future generations, leading to the gradual evolution of a species.
3. Mutations and genetic recombination during reproduction introduce new genetic variations, providing the raw material for natural selection to act upon.
4. Populations that are geographically isolated or face different environmental pressures may undergo divergent evolution, leading to the formation of new species.
5. Natural selection is a key mechanism that drives the evolution of complex adaptations, such as the development of specialized organs, behaviors, and physiological processes.

Review Questions

• Explain how natural selection leads to the adaptation of a species to its environment.
  • Natural selection is the process by which individuals with favorable traits that enhance their survival and reproductive success are more likely to pass on those traits to their offspring. Over successive generations, the population will gradually become better adapted to the environment as the advantageous traits become more prevalent. This is because individuals with these traits are more likely to survive and reproduce, while those with less favorable traits are less likely to contribute to the gene pool. Through this process of differential reproduction, the population evolves to be better suited to its environment.
• Describe the role of genetic variation in the process of natural selection.
  • Genetic variation within a population is essential for natural selection to occur. Genetic variation arises from mutations, genetic recombination during sexual reproduction, and other genetic processes. This variation provides the raw material for natural selection to act upon, as individuals with different genetic makeups will have varying traits and abilities to survive and reproduce in a given environment. Populations with greater genetic diversity are more likely to have individuals with traits that confer a survival advantage, which can then be passed on to future generations. Without genetic variation, natural selection would be unable to act, and the population would be unable to adapt to changing environmental conditions.
• Analyze how the principle of 'survival of the fittest' relates to the mechanism of natural selection.
  • The principle of 'survival of the fittest' is closely tied to the mechanism of natural selection. It refers to the idea that individuals with the most favorable traits, or the 'fittest' individuals, are more likely to survive and reproduce, passing on their advantageous characteristics to their offspring. This process of differential reproduction leads to the gradual evolution of a population, as the less fit individuals are less likely to contribute to the gene pool. Natural selection acts as the driving force behind this process, favoring the individuals with traits that confer a survival or reproductive advantage in a given environment. Over time, this results in the adaptation of a species to its surroundings, as the population becomes increasingly well-suited to thrive and reproduce in its ecological niche.

Related terms

Adaptation: The process by which an organism or species becomes better suited to its environment over time, through genetic changes that are passed down from one generation to the next.

Genetic Variation: The differences in the genetic makeup of individuals within a population, which allows for the selection of advantageous traits during the process of natural selection.

Survival of the Fittest: The principle that individuals or species best adapted to their environment are more likely to survive and reproduce, passing on their favorable traits to their offspring.