Continuing Evolution - AP Biology
- Identify the selection type that reduces the frequency of harmful alleles.
- Purifying selection. Eliminates deleterious alleles to maintain population health.
- What is the definition of evolution in biological terms?
- Change in allele frequencies in a population over time. Evolution is measured by tracking changes in gene frequencies across generations.
- Identify the model that suggests evolution occurs in rapid bursts.
- Punctuated equilibrium. Rapid evolutionary change followed by periods of stasis.
- What is the term for an organism's observable traits?
- Phenotype. Physical expression of genetic information in organisms.
- What is the term for a group of interbreeding individuals of the same species?
- Population. Members can potentially interbreed and share a gene pool.
- What is the term for a trait that no longer serves its original purpose?
- Vestigial structure. Remnants of ancestral features lost through disuse.
- Identify the concept where allele frequencies remain constant in a population.
- Hardy-Weinberg equilibrium. Requires no mutation, selection, migration, or genetic drift.
- Which process describes the spread of advantageous alleles throughout a population?
- Selective sweep. Beneficial alleles rapidly increase in frequency.
- Identify the term for changes in a species over time due to environmental pressures.
- Adaptation. Traits that enhance survival in specific environments become common.
- What is the term for genetic exchange between different populations?
- Gene flow. Movement of alleles between populations maintains genetic diversity.
- What is the term for the formation of new species from a common ancestor?
- Speciation. Reproductive isolation leads to distinct evolutionary lineages.
- Which model of evolution describes gradual changes over long periods?
- Gradualism. Continuous, steady accumulation of small evolutionary changes.
- Identify the process where two populations become reproductively isolated.
- Speciation. Geographic or behavioral barriers prevent gene flow.
- What is the term for genetic changes that occur without affecting fitness?
- Neutral mutation. Changes have no effect on survival or reproduction.
- Identify the concept of a single species evolving into different forms.
- Adaptive radiation. One ancestral species diversifies to fill multiple ecological niches.
- What type of evolution involves species evolving in response to each other?
- Coevolution. Reciprocal evolutionary changes driven by species interactions.
- Identify the process by which new genetic variations arise.
- Mutation. DNA changes provide raw material for evolutionary change.
- Identify the process that causes random changes in allele frequencies.
- Genetic drift. Random sampling of alleles, especially strong in small populations.
- Which type of selection favors extreme phenotypes at both ends of the spectrum?
- Disruptive selection. Selects against average traits, increasing population variance.
- What is the term for the divergence of two species into different forms?
- Divergent evolution. Related species develop different traits in different environments.
- What is the term for a reduction in an organism's fitness due to genetic changes?
- Genetic load. Harmful mutations reduce overall population fitness.
- Which type of selection increases the frequency of a beneficial allele?
- Positive selection. Advantageous mutations spread through populations over time.
- What process involves changes in allele frequencies due to chance events?
- Genetic drift. Random changes are strongest in smaller populations.
- What is the term for the study of past and present distribution of species?
- Biogeography. Geographic patterns reveal evolutionary and ecological relationships.
- Identify the process by which unrelated organisms evolve similar traits.
- Convergent evolution. Similar environments produce similar adaptive solutions.
- Which effect describes reduced genetic variation after a population bottleneck?
- Bottleneck effect. Population crashes eliminate many alleles randomly.
- What is the term for the introduction of new alleles into a population?
- Gene flow. Migration brings new genetic variants into populations.
- Which term describes the evolutionary history of a species or group?
- Phylogeny. Evolutionary relationships revealed through genetic and morphological data.
- What is the term for evolutionary changes that occur at or above the level of species?
- Macroevolution. Large-scale patterns of evolutionary change across taxa.
- What is the term for the gradual change in species over time?
- Evolution. Descent with modification produces biological diversity.
- What type of selection favors intermediate phenotypes over extremes?
- Stabilizing selection. Reduces variation by selecting against extreme phenotypes.
- Which term describes the phenomenon of decreased diversity after a bottleneck?
- Genetic drift. Random allele loss during population bottlenecks reduces diversity.
- Identify the selection type that acts against both extreme phenotypes.
- Stabilizing selection. Maintains population around the optimal phenotypic mean.
- What is the definition of a homologous structure?
- Structures with a common evolutionary origin. Similar structures indicate shared evolutionary ancestry.
- Which type of selection acts against individuals at one extreme of a trait?
- Directional selection. Shifts trait distribution toward one extreme phenotype.
- Which term describes species that evolve from a common ancestor?
- Common descent. All life shares common ancestors through evolutionary history.
- What is a measure of an organism's ability to survive and reproduce?
- Fitness. Higher fitness means greater contribution to future generations.
- Which mechanism of evolution results from differential survival and reproduction?
- Natural selection. Organisms with favorable traits reproduce more successfully.