Bio: Convergent & Divergent Evolution

Convergent:

• Different species that are unrelated or not closely related species evolve similar traits because they live in similar environments or face similar challenges

• This happens when natural selection favors similar adaptations in different species

• Ex: Both sharks and dolphins have streamlined bodies and fins for swimming, but sharks are fish and dolphins are mammals

Analogous structures

• Structures that perform a similar function but have a different evolutionary history

• They show convergent evolution as organisms who live in a similar environment have evolved similar adaptations

• This evidence reinforces the importance of homologous evidence since we know there are multiple ways in which a species can evolve a fin or a wing

Divergent

• Closely related species evolve different traits because they adapt to different environments

• Happens when a common ancestor gives rise to species with different adaptations over time

• Ex: Darwin’s finches developed different beak shapes to eat different types of food on the Galapagos Islands

• When a single ancestor species experiences many speciation events and diverges into many different species this is called adaptive radiation