Natural selection

Definition

Natural selection is the process by which organisms that are better adapted to their environment tend to survive and reproduce more successfully than those that are less adapted. This concept is a key mechanism of evolution, driving the gradual changes in species over time and leading to diversification, including the evolution of terrestrial plants. Through mechanisms like variation, competition, and environmental pressures, natural selection plays a critical role in shaping the traits of plant species as they adapt to varying terrestrial habitats.

5 Must Know Facts For Your Next Test

1. Natural selection acts on existing variations within a population, favoring individuals with traits that provide an advantage in their specific environment.
2. In terrestrial plants, natural selection can influence traits like drought resistance, growth patterns, and reproductive strategies, affecting their distribution and diversity.
3. The concept was first popularized by Charles Darwin and Alfred Russel Wallace in the 19th century, fundamentally changing our understanding of evolution.
4. Natural selection can lead to co-evolution, where different species influence each other's adaptations, such as plants evolving specific traits to attract pollinators.
5. The fossil record provides evidence for natural selection by showing changes in plant forms over time that correspond with changes in climate and environment.

Review Questions

• How does natural selection contribute to the adaptation of terrestrial plants in various environments?
  • Natural selection contributes to the adaptation of terrestrial plants by favoring individuals that possess traits enhancing their survival in specific environments. For example, in arid regions, plants with deeper roots or waxy leaves may thrive better due to their ability to conserve water. Over generations, these advantageous traits become more common within the population, leading to a diverse range of plant species adapted to different ecological niches.
• Discuss the role of mutation and genetic variation in the process of natural selection among plant species.
  • Mutations introduce genetic variation within plant populations, providing the raw material on which natural selection acts. Some mutations may confer beneficial traits that enhance survival or reproduction under certain environmental conditions. Over time, these favorable traits can spread through the population as individuals possessing them are more likely to survive and reproduce. This dynamic interplay between mutation and natural selection drives the evolution and diversification of plant species.
• Evaluate how natural selection has shaped the evolution of complex plant interactions such as symbiosis and co-evolution.
  • Natural selection has significantly influenced the evolution of complex interactions between plants and other organisms through processes like symbiosis and co-evolution. For instance, flowering plants have evolved specific traits to attract certain pollinators, which in turn affect their reproductive success. As these interactions evolve, both plants and pollinators can develop specialized adaptations that enhance their mutual benefits. This intricate relationship showcases how natural selection not only shapes individual species but also drives broader ecological dynamics.

Related terms

adaptation: A characteristic or trait that enhances the survival and reproduction of an organism in its environment.

mutation: A change in the DNA sequence of an organism that can lead to new traits and variations, some of which may be beneficial for survival.

speciation: The evolutionary process by which populations evolve to become distinct species, often as a result of natural selection acting on variations within populations.