Natural selection

Definition

Natural selection is a fundamental process in evolutionary biology where organisms better adapted to their environment tend to survive and produce more offspring. This process leads to the gradual evolution of species over generations as advantageous traits become more common. It plays a crucial role in shaping the genetic makeup of populations and contributes to the development of evolutionary stable strategies within the framework of replicator dynamics.

5 Must Know Facts For Your Next Test

1. Natural selection operates on existing variations within a population, favoring those traits that confer survival or reproductive advantages.
2. The concept was first formulated by Charles Darwin and Alfred Russel Wallace in the 19th century, leading to a paradigm shift in understanding biological evolution.
3. In the context of evolutionary stable strategies, natural selection influences which strategies persist in a population based on their relative success in competing for resources and mates.
4. Natural selection can lead to adaptive radiation, where organisms diversify rapidly into a variety of forms to exploit different ecological niches.
5. The process is not goal-oriented; it results from environmental pressures and interactions among individuals rather than a predetermined direction or purpose.

Review Questions

• How does natural selection contribute to the development of evolutionary stable strategies in populations?
  • Natural selection shapes evolutionary stable strategies by favoring traits that enhance survival and reproductive success within specific environments. Strategies that are more effective at competing for resources or mates will tend to increase in frequency over time. As these strategies become prevalent, they establish a stable equilibrium within the population, influencing which traits persist and how species evolve.
• Discuss how natural selection interacts with genetic drift and its implications for population dynamics.
  • Natural selection and genetic drift are both mechanisms of evolution that can impact population dynamics, but they operate differently. Natural selection acts on adaptive traits, increasing their frequency based on fitness advantages, while genetic drift involves random fluctuations in allele frequencies, often affecting small populations disproportionately. The interplay between these two processes can lead to significant changes in genetic diversity and evolutionary outcomes, especially under changing environmental conditions.
• Evaluate the role of natural selection in driving evolutionary changes in response to environmental pressures and how this may affect future species development.
  • Natural selection plays a critical role in driving evolutionary changes by selecting for traits that enhance survival under specific environmental pressures. As environments change—due to factors like climate change, habitat loss, or introduction of invasive species—natural selection can lead to rapid adaptations or shifts in population structures. This ongoing process may result in the emergence of new species or the extinction of those unable to adapt, illustrating how natural selection influences not only current biodiversity but also shapes the future trajectory of life on Earth.

Related terms

evolution: The change in the heritable characteristics of biological populations over successive generations, often driven by natural selection.

fitness: A measure of an organism's ability to survive and reproduce in its environment, often determined by its genetic traits.

genetic drift: A mechanism of evolution that involves random changes in the frequency of alleles in a population, which can affect the overall genetic diversity.