Evolution occurs when…

• Individual organisms change traits so they can survive better.

• The allele frequencies in a population change over time.
  

• Natural selection chooses the strongest individuals.

• A species becomes perfectly adapted to the environment.

Which mechanism is the only source of new alleles in a population?

• Migration

• Natural selection

• Mutation

• Genetic drift

A hurricane kills 90% of a population randomly. The remaining 10% reproduce. This illustrates…

• Founder effect

• 
  Stabilizing selection

• Bottleneck (genetic drift)

• 
  Directional selection

Which of these is TRUE of migration (gene flow)?

• It only affects the population that receives the migrants.

• It reduces allele frequency changes.

• Alleles move into and out of populations, changing both groups.

• It always increases fitness.

Natural selection requires all EXCEPT:

• Variation for a trait

• Heritability

• Differential reproductive success

• Random mating preferences

“Fitness” means:

• Being the strongest physically

• Living the longest

• Producing more offspring than others with different phenotypes

• Having no harmful alleles

When extreme phenotypes have the highest fitness, this is:

• Directional selection

• Disruptive selection

• Stabilizing selection

• Artificial selection

Artificial selection is essentially:

• Evolution without selection

• Humans guiding natural selection

• Evolution caused only by mutation

• Fitness increasing without reproduction

Fossils allow scientists to…

• Prove evolution only in extinct organisms.

• Reconstruct ancient organisms and evolutionary relationships.

• Measure reproductive success in the past.

• Determine exact mutation timing.

Similar structures with different functions (mammal forelimbs) are called:

• Analogous structures

• Vestigial structures

• Homologous structures

• Adaptive mutations