Evidence of Evolution - AP Biology

What is the primary source of genetic variation in populations?

Mutations. Creates new alleles that natural selection can act upon.
Which term describes a rapid burst of evolutionary change?

Punctuated equilibrium. Contrasts with gradual evolutionary change over time.
Which term describes the independent evolution of similar traits?

Convergent evolution. Different species develop similar solutions to environmental challenges.
Which molecule is commonly used to study molecular homology?

DNA. DNA sequences reveal evolutionary relationships between species.
Which type of selection favors intermediate phenotypes?

Stabilizing selection. Reduces variation by selecting against extreme phenotypes.
Which evolutionary mechanism involves random changes in allele frequencies?

Genetic drift. Operates independently of natural selection pressures.
What does a phylogenetic tree represent?

Evolutionary relationships among species. Branch points show when lineages diverged from ancestors.
What is allopatric speciation?

Speciation due to geographic isolation. Physical barriers prevent gene flow between populations.
What is the term for a trait that enhances an organism's survival and reproduction?

Adaptation. Increases fitness by improving survival or reproduction.
What is a clade?

A group of species that includes an ancestral species and its descendants. Represents a complete evolutionary branch on phylogenetic trees.
What is gene flow?

Exchange of genes between populations. Migration introduces new alleles to populations.
Which formula represents the Hardy-Weinberg equilibrium?

$p^2 + 2pq + q^2 = 1$ . Where $p$ and $q$ represent allele frequencies in population.
What is the significance of embryological similarities?

Common ancestry. Similar embryonic development patterns indicate shared ancestry.
What is the bottleneck effect?

A sharp reduction in population size and genetic diversity. Causes loss of genetic diversity in surviving population.
What type of evolution is illustrated by the similarity in wings of birds and insects?

Convergent evolution. Similar functions evolved independently in different lineages.
Which process can lead to genetic divergence in isolated populations?

Allopatric speciation. Geographic separation reduces gene flow between populations.
What is sympatric speciation?

Speciation without geographic isolation. Can occur through polyploidy or ecological specialization.
What term describes the formation of new species?

Speciation. Occurs when populations become reproductively isolated.
Which structures are examples of homologous structures?

Forelimbs of humans and wings of bats. Same bone structure, different functions show common ancestry.
Which scientist is known for the theory of evolution by natural selection?

Charles Darwin. Proposed natural selection as the mechanism of evolution.
What is the significance of transitional fossils?

They show intermediate forms between ancestral and derived species. Bridge gaps in evolutionary history between major groups.
What is a vestigial structure?

A structure with no current function, inherited from an ancestor. Examples include appendix in humans or hip bones in whales.
What is an evolutionary tree?

A diagram showing evolutionary relationships among species. Visual representation of phylogenetic relationships over time.
Identify the process by which populations become better suited to their environment.

Adaptation. Results from natural selection favoring beneficial traits.
What do analogous structures demonstrate?

Convergent evolution. Similar functions evolved independently in unrelated species.
What does the Hardy-Weinberg principle describe?

A non-evolving population's allele frequencies. Serves as null hypothesis for detecting evolutionary change.
How does biogeography provide evidence for evolution?

Species distribution correlates with geographical features and history. Isolation leads to unique species on islands and continents.
What is the role of mutations in evolution?

Source of genetic variation. Provides raw material for natural selection to act upon.
What is the founder effect?

Genetic differences in a population founded by a small number of individuals. Small founding population lacks full genetic diversity.
What is a monophyletic group?

A group consisting of a single ancestral species and all its descendants. Includes all descendants with no missing branches.
What is coevolution?

Reciprocal evolutionary change between interacting species. Examples include flowering plants and their pollinators.
How does comparative anatomy support the theory of evolution?

By showing homologous structures indicating common ancestry. Structural similarities reveal common evolutionary origins.
What is the principle of natural selection?

Survival and reproduction of organisms best suited to the environment. This describes the mechanism driving evolutionary change.
What is an example of adaptive radiation?

Darwin's finches diversifying into different niches. One ancestral species rapidly diversifies into multiple species.
Identify a type of evidence for evolution from paleontology.

Fossil records showing transitional forms. Fossils provide direct historical evidence of evolutionary change.
Which type of selection favors extreme phenotypes?

Disruptive selection. Selects against intermediate phenotypes, increases variation.
Which structures indicate divergent evolution?

Homologous structures. Same structure modified for different functions over time.
Which type of evidence is provided by DNA sequencing?

Molecular homology. Compares genetic sequences to determine relationships.
Which type of selection results in a shift toward one extreme phenotype?

Directional selection. Favors one end of the phenotypic range over the other.
What is genetic drift?

Random changes in allele frequencies in a population. More pronounced in smaller populations due to sampling error.

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