01 Evolution and Natural Selection Free Online FlashCards

What is evolution?

Evolution is a change in the inherited characteristics, or genetic makeup, of a population across generations.

Name two processes that generate genetic variation.

Mutation and recombination generate genetic variation; genetic drift and gene flow can also change variant frequencies in populations.

What three conditions are required for natural selection?

Natural selection requires trait variation, some heritability, and differences in surviving offspring associated with inherited traits.

What determines which inherited traits natural selection favors?

Natural selection occurs when individuals with certain inherited traits leave more surviving offspring on average than others.

How can antibiotic use increase bacterial resistance?

Antibiotics select among bacterial variants: susceptible bacteria are more likely to die, while resistant bacteria are more likely to reproduce.

What is an adaptation?

An adaptation is an inherited feature that contributes to survival or reproductive success in a particular environment.

What are three forms an adaptation can take?

Adaptations may be structural, physiological, or behavioral.

Why is a trait not always advantageous?

A trait advantageous in one environment may be neutral or harmful in another, and adaptation to current conditions does not guarantee suitability for future ones.

What is speciation?

Speciation is the formation of new species as populations diverge.

How does the biological species concept define a species?

Under the biological species concept, a species consists of populations whose members can potentially interbreed and produce viable, fertile offspring.

How do allopatric and sympatric speciation differ?

Allopatric speciation follows geographic separation; sympatric speciation occurs without geographic separation, such as when chromosome-number changes prevent successful breeding.

Which evolves: an individual or a population?

Individuals develop during their lives; populations evolve as inherited variant frequencies change across generations.