Divergent evolution

Definition

Divergent evolution is the process by which two or more related species become more dissimilar over time, often due to different environmental pressures and adaptations. This process highlights how species that share a common ancestor can evolve unique traits and behaviors as they adapt to various ecological niches. It is a key concept in understanding the patterns of evolution and is often illustrated using phylogenetic trees, which depict the relationships and evolutionary paths of different species.

5 Must Know Facts For Your Next Test

1. Divergent evolution occurs when populations of a species are exposed to different selective pressures, leading to the development of distinct traits over time.
2. This process can be observed in closely related species, such as Darwin's finches, which adapted to different food sources on the Galápagos Islands.
3. Divergent evolution contributes to biodiversity by allowing species to exploit different ecological roles and environments.
4. The concept is essential for constructing phylogenetic trees, as it helps illustrate how species have evolved from common ancestors and adapted to their surroundings.
5. Molecular evidence, such as genetic sequences, can support findings of divergent evolution by showing variations in DNA among related species.

Review Questions

• How does divergent evolution explain the differences between closely related species?
  • Divergent evolution explains the differences between closely related species through the concept of adaptation to varying environments. When species that share a common ancestor experience different ecological pressures, they evolve distinct traits that enhance their survival in specific conditions. This results in increased dissimilarity among these species over time, even though they originate from the same lineage.
• In what ways do homologous structures provide evidence for divergent evolution?
  • Homologous structures provide evidence for divergent evolution by showcasing how different species have developed variations of the same anatomical features from a common ancestor. For example, the forelimbs of mammals like humans, whales, and bats are structurally similar but serve different functions. This structural similarity indicates that these species evolved from a shared ancestor while adapting to their unique environments, thus illustrating the process of divergent evolution.
• Evaluate the role of adaptive radiation in understanding divergent evolution within phylogenetic trees.
  • Adaptive radiation plays a crucial role in understanding divergent evolution as it highlights how a single ancestral species can rapidly diversify into multiple forms that occupy various ecological niches. In phylogenetic trees, this rapid diversification is illustrated by branching patterns that show how closely related species evolved distinct traits in response to differing environmental challenges. Analyzing these branches allows scientists to trace back evolutionary paths and comprehend the mechanisms driving biodiversity through divergent evolution.

Related terms

Adaptive Radiation:

A rapid diversification of a single lineage into a variety of forms that adapt to different environments or ecological niches.

Homologous Structures: Anatomical features in different species that are similar due to shared ancestry, but may serve different functions as a result of divergent evolution.

Phylogenetic Tree: A diagram that represents the evolutionary relationships among various biological species, illustrating their divergence from common ancestors.