Natural Selection

What is the definition of biological evolution in the context of population genetics?

• Changes in an individual organism's traits over its lifetime.

• Changes in the gene pool of a population over time.

• The development of new species from existing ones.

• The process by which organisms become more complex.

Which of the following conditions, if violated, would lead to a change in the allele frequencies within a gene pool, thus causing evolution?

• Large population size.

• Random mating.

• No mutations.

• All of the above.

What are the primary mechanisms that introduce new genetic characteristics into a population and rearrange existing ones, respectively?

• Natural selection and genetic drift.

• Mutation and reproduction.

• Migration and non-random mating.

• Adaptation and fitness.

What environmental change during the Industrial Revolution led to a decrease in the fitness of light-colored peppered moths?

• Increased availability of light-colored food sources.

• A decrease in the population of predatory birds.

• The darkening of tree bark due to industrial pollution.

• A new disease affecting only light-colored moths.

In the Hardy-Weinberg equilibrium example for peppered moths, if 98% of the population were light-colored (recessive phenotype) in 1848, what was the approximate allele frequency (q) for the recessive allele?

• 0.02

• 0.14

• 0.99

• 0.49

The Cichlid fish in the African Rift Valley lakes exhibit a unique anatomical feature that has contributed to their rapid diversification. What is this feature?

• Specialized fins for faster swimming.

• A second, pharyngeal jaw for processing different foods.

• Bioluminescent organs for attracting mates.

• Gills adapted for both fresh and saltwater environments.

Which of the following best defines natural selection?

• The process by which organisms acquire traits during their lifetime and pass them to offspring.

• Random changes in an organism's DNA that lead to new species.

• The differential reproductive success of individuals based on their heritable traits.

• The intentional breeding of organisms by humans to select for desirable traits.