Biology HN-Evolution-Day 4

What are homologous structures?

Structures that are similar because organisms share a common ancestor, resulting from divergent evolution.

What is divergent evolution?

When species share a common ancestor but evolve into different species.

Provide an example of homologous structures.

Forelimbs of vertebrates such as crocodiles, whales, bats, cats, and humans.

What memory trick can help remember homologous structures and divergent evolution?

HD TV: H = homologous structure, D = divergent evolution.

What are vestigial structures?

Structures that are no longer used by an organism, providing evidence for evolutionary change.

Give an example of a vestigial structure.

Hind leg bones in whale fossils or the human tailbone.

What are analogous structures?

Structures that are similar due to similar environments, but do not share a common ancestor.

What is convergent evolution?

When organisms evolve similar traits due to similar environments, not because of a common ancestor.

Provide an example of analogous structures.

Wings of butterflies and birds.

What memory trick can help remember analogous structures and convergent evolution?

AC: A = analogous structure, C = convergent evolution.

What is genetic drift?

A mechanism of evolution that involves random changes in allele frequencies in a population.

What is the Founder Effect?

A type of genetic drift that occurs when a small group from a population establishes a new population.

What is the Bottleneck Effect?

A type of genetic drift that occurs when a population's size is significantly reduced, leading to a loss of genetic diversity.

What are the four mechanisms of evolution?

Mutation, Natural Selection, Gene Flow (Migration), and Genetic Drift.