Natural Selection

Definition

Natural selection is the process through which organisms better adapted to their environment tend to survive and produce more offspring. This mechanism is a key driver of evolution, influencing traits related to survival, reproduction, and behavior across generations.

5 Must Know Facts For Your Next Test

1. Natural selection operates on variations within a population, favoring traits that improve survival and reproductive success.
2. Over time, natural selection can lead to speciation, where new species evolve from a common ancestor due to adaptations to different environments.
3. The theory of natural selection was first formulated by Charles Darwin and is one of the cornerstones of modern evolutionary biology.
4. Natural selection is influenced by environmental factors such as climate, availability of resources, and predation pressures.
5. Human behaviors can also be subject to natural selection, as traits that promote social cohesion or reproductive success may be favored over generations.

Review Questions

• How does natural selection influence human behavior in terms of adaptation and survival?
  • Natural selection shapes human behavior by favoring traits that enhance survival and reproductive success. For instance, behaviors that promote cooperation or social bonding may have been favored because they enhance group cohesion and increase the chances of survival. Over time, these adaptive behaviors can become prevalent within a population, reflecting the influence of environmental challenges and social dynamics on our evolution.
• Evaluate the role of natural selection in the context of human biological diversity and race.
  • Natural selection contributes significantly to human biological diversity by favoring specific traits in populations based on environmental pressures. Differences in skin color, for example, have evolved as adaptations to varying levels of UV radiation in different geographic areas. These adaptations illustrate how natural selection can lead to diversity among human populations while still connecting us all through our shared ancestry.
• Assess how the principles of natural selection can be applied in evolutionary medicine for disease prevention.
  • In evolutionary medicine, understanding natural selection allows researchers to identify how certain genetic traits might confer resistance or susceptibility to diseases. By studying patterns of human adaptation over time, we can better understand why certain populations are more prone to specific health issues. This knowledge can inform strategies for disease prevention and treatment by emphasizing the importance of genetic factors shaped by natural selection throughout human history.

Related terms

Fitness:

In evolutionary biology, fitness refers to an organism's ability to survive, reproduce, and pass on its genes to the next generation.

Adaptation:

Adaptation is the process by which a species becomes better suited to its environment through changes in traits that enhance survival and reproduction.

Genetic Drift:

Genetic drift is the random fluctuation of allele frequencies in a population, which can lead to changes in genetic diversity and affect natural selection.