AP Biology Flashcards: Natural Selection Continued

What this deck covers

This deck focuses on Natural Selection Continued, giving you a quick way to review the definitions, rules, and examples that matter most for AP Biology.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Identify a process that can counteract natural selection by maintaining variation.

Answer: Gene flow. Immigration introduces new alleles that may be selected against.

Flashcard 2: Which term refers to a trait that arises due to common ancestry?

Answer: Homologous trait. Shared evolutionary origin produces similar structures across species.

Flashcard 3: Which term describes the loss of genetic variation due to random events?

Answer: Genetic drift. Random sampling effects strongest in small populations.

Flashcard 4: Which term describes changes in allele frequencies due to random sampling?

Answer: Genetic drift. Random changes occur independently of natural selection pressures.

Flashcard 5: Identify a consequence of genetic drift.

Answer: Reduced genetic diversity. Random events remove alleles regardless of their fitness value.

Flashcard 6: What is an adaptation?

Answer: A heritable trait that increases fitness. Must be both inherited and beneficial for survival or reproduction.

Flashcard 7: Which term describes a trait that no longer serves its original purpose?

Answer: Vestigial trait. Remains due to evolutionary history despite loss of function.

Flashcard 8: What is a gene pool?

Answer: The total collection of genes in a population. Contains all genetic material available for natural selection.

Flashcard 9: Which phenomenon can result from random mating in large populations?

Answer: Hardy-Weinberg equilibrium. Describes stable allele frequencies when evolution is not occurring.

Flashcard 10: What role does genetic variation play in natural selection?

Answer: It provides the raw material for selection. Without variation, natural selection cannot act on populations.

Flashcard 11: What is a selective sweep?

Answer: A process where a favorable allele increases in frequency. Strong selection rapidly increases beneficial allele frequency.

Flashcard 12: What is sexual dimorphism?

Answer: Distinct differences in size or appearance between sexes. Results from different selective pressures on males and females.

Flashcard 13: Which term describes selection that acts against both extreme phenotypes?

Answer: Stabilizing selection. Maintains population around the average phenotype value.

Flashcard 14: What is the definition of natural selection?

Answer: The process by which organisms better adapted to their environment tend to survive and reproduce. Darwin's mechanism for evolution through environmental pressures.

Flashcard 15: What is artificial selection?

Answer: Selective breeding by humans to enhance desirable traits. Humans act as the selective pressure instead of nature.

Flashcard 16: Identify the main driving force of natural selection.

Answer: Environmental pressures. External factors that determine which organisms survive and reproduce.

Flashcard 17: Identify a process that can counteract natural selection by maintaining variation.

Answer: Gene flow. Immigration introduces new alleles that may be selected against.

Flashcard 18: What is the role of recombination in evolution?

Answer: Shuffles alleles, creating new combinations. Independent assortment and crossing over increase genetic diversity.

Flashcard 19: What is an adaptation?

Answer: A heritable trait that increases fitness. Must be both inherited and beneficial for survival or reproduction.

Flashcard 20: Which type of selection favors extreme phenotypes?

Answer: Disruptive selection. Selects against intermediate values, increasing variation.

Flashcard 21: Which term describes changes in allele frequencies due to random sampling?

Answer: Genetic drift. Random changes occur independently of natural selection pressures.

Flashcard 22: What is directional selection?

Answer: Selection that favors one extreme phenotype. Shifts population toward one end of the trait distribution.

Flashcard 23: Identify a factor that can lead to reproductive isolation.

Answer: Geographic barriers. Physical separation prevents gene flow between populations.

Flashcard 24: Which term describes the loss of genetic variation due to random events?

Answer: Genetic drift. Random sampling effects strongest in small populations.

Flashcard 25: What is coevolution?

Answer: Reciprocal evolutionary changes in interacting species. Species evolve in response to each other's evolutionary changes.

Flashcard 26: What is the significance of a selection coefficient?

Answer: It measures the strength of selection against a genotype. Quantifies how much a genotype reduces reproductive success.

Flashcard 27: What is sexual dimorphism?

Answer: Distinct differences in size or appearance between sexes. Results from different selective pressures on males and females.

Flashcard 28: Identify a source of genetic variation in a population.

Answer: Recombination. Crossing over during meiosis creates new allele combinations.

Flashcard 29: Which factor can increase genetic variation within a population?

Answer: Mutation. Creates new alleles that increase genetic diversity.

Flashcard 30: Which term refers to the movement of alleles between populations?

Answer: Gene flow. Migration transfers genetic material between populations.

Flashcard 31: What is a selective pressure?

Answer: An environmental factor that influences survival and reproduction. Determines which traits are advantageous or disadvantageous.

Flashcard 32: What is the significance of a selection coefficient?

Answer: It measures the strength of selection against a genotype. Quantifies how much a genotype reduces reproductive success.

Flashcard 33: Which type of selection can lead to speciation?

Answer: Disruptive selection. Can split populations into distinct groups with different traits.

Flashcard 34: Identify a factor that can lead to adaptive radiation.

Answer: Ecological opportunities. New environments allow rapid diversification into multiple niches.

Flashcard 35: What is a polymorphism?

Answer: The occurrence of different forms among individuals of a population. Multiple alleles maintained in population by various selective pressures.

Flashcard 36: Which term refers to a trait that arises due to common ancestry?

Answer: Homologous trait. Shared evolutionary origin produces similar structures across species.

Flashcard 37: Identify the result of a population's adaptation to its environment over time.

Answer: Increased fitness. Better-adapted populations have higher survival and reproductive rates.

Flashcard 38: What is a gene pool?

Answer: The total collection of genes in a population. Contains all genetic material available for natural selection.

Flashcard 39: Identify a result of stabilizing selection.

Answer: Reduction in phenotypic variation. Average phenotypes have highest fitness, reducing population variation.

Flashcard 40: Which phenomenon can result from random mating in large populations?

Answer: Hardy-Weinberg equilibrium. Describes stable allele frequencies when evolution is not occurring.

Flashcard 41: Identify a consequence of genetic drift.

Answer: Reduced genetic diversity. Random events remove alleles regardless of their fitness value.

Flashcard 42: Identify a mechanism that can lead to genetic drift.

Answer: Bottleneck effect. Random reduction in population size that reduces genetic diversity.

Flashcard 43: Which term refers to the movement of alleles between populations?

Answer: Gene flow. Migration transfers genetic material between populations.

Flashcard 44: Which term describes the differential survival and reproduction of individuals?

Answer: Differential fitness. Measures relative reproductive success among individuals in a population.

Flashcard 45: What is the role of recombination in evolution?

Answer: Shuffles alleles, creating new combinations. Independent assortment and crossing over increase genetic diversity.

Flashcard 46: Identify a factor that can lead to reproductive isolation.

Answer: Geographic barriers. Physical separation prevents gene flow between populations.

Flashcard 47: Which type of selection favors extreme phenotypes?

Answer: Disruptive selection. Selects against intermediate values, increasing variation.

Flashcard 48: Identify a mechanism that can lead to genetic drift.

Answer: Bottleneck effect. Random reduction in population size that reduces genetic diversity.

Flashcard 49: What is the definition of natural selection?

Answer: The process by which organisms better adapted to their environment tend to survive and reproduce. Darwin's mechanism for evolution through environmental pressures.

Flashcard 50: What is meant by 'fitness' in the context of natural selection?

Answer: The ability to survive and reproduce. Measures an organism's reproductive success relative to others.

Flashcard 51: What is genetic hitchhiking?

Answer: An allele's increase in frequency due to linkage with a favorable allele. Neutral allele increases due to proximity to beneficial allele.

Flashcard 52: Which term describes a trait that no longer serves its original purpose?

Answer: Vestigial trait. Remains due to evolutionary history despite loss of function.

Flashcard 53: Identify the result of a population's adaptation to its environment over time.

Answer: Increased fitness. Better-adapted populations have higher survival and reproductive rates.

Flashcard 54: How does sexual selection differ from natural selection?

Answer: Sexual selection focuses on traits that improve mating success. Sexual selection specifically targets reproductive success over survival.

Flashcard 55: Which term describes the differential survival and reproduction of individuals?

Answer: Differential fitness. Measures relative reproductive success among individuals in a population.

Flashcard 56: What is a polymorphism?

Answer: The occurrence of different forms among individuals of a population. Multiple alleles maintained in population by various selective pressures.

Flashcard 57: How does sexual selection differ from natural selection?

Answer: Sexual selection focuses on traits that improve mating success. Sexual selection specifically targets reproductive success over survival.

Flashcard 58: What role does genetic variation play in natural selection?

Answer: It provides the raw material for selection. Without variation, natural selection cannot act on populations.

Flashcard 59: Which type of selection favors intermediate phenotypes?

Answer: Stabilizing selection. Reduces variation by selecting against extreme values.

Flashcard 60: Identify a result of stabilizing selection.

Answer: Reduction in phenotypic variation. Average phenotypes have highest fitness, reducing population variation.

Flashcard 61: What is genetic hitchhiking?

Answer: An allele's increase in frequency due to linkage with a favorable allele. Neutral allele increases due to proximity to beneficial allele.

Flashcard 62: Which term describes selection that acts against both extreme phenotypes?

Answer: Stabilizing selection. Maintains population around the average phenotype value.

Flashcard 63: Which type of selection can lead to speciation?

Answer: Disruptive selection. Can split populations into distinct groups with different traits.

Flashcard 64: What is meant by 'fitness' in the context of natural selection?

Answer: The ability to survive and reproduce. Measures an organism's reproductive success relative to others.

Flashcard 65: Which factor can increase genetic variation within a population?

Answer: Mutation. Creates new alleles that increase genetic diversity.

Flashcard 66: Which type of selection favors one phenotype over others?

Answer: Directional selection. Creates consistent change in one direction over time.

Flashcard 67: Identify a factor that can lead to adaptive radiation.

Answer: Ecological opportunities. New environments allow rapid diversification into multiple niches.

Flashcard 68: Which type of selection favors one phenotype over others?

Answer: Directional selection. Creates consistent change in one direction over time.

Flashcard 69: Identify the main driving force of natural selection.

Answer: Environmental pressures. External factors that determine which organisms survive and reproduce.

Flashcard 70: Identify a source of genetic variation in a population.

Answer: Recombination. Crossing over during meiosis creates new allele combinations.

Flashcard 71: What is a selective pressure?

Answer: An environmental factor that influences survival and reproduction. Determines which traits are advantageous or disadvantageous.

Flashcard 72: What is the founder effect?

Answer: Genetic drift occurring when a new population is established. Small founding population carries limited genetic diversity.

Flashcard 73: What is a selective sweep?

Answer: A process where a favorable allele increases in frequency. Strong selection rapidly increases beneficial allele frequency.