Natural Selection
Naturalist who studied living organisms in the galapagos. Known for finches and developing the theory of Natural Selection
Charles Darwin
These preserved remains or impressions of ancient organisms help scientists study how species have changed over time.
fossils
This type of speciation occurs when a population is physically separated by a barrier, like a river or mountain, preventing gene flow.
This principle provides a model to study populations that are not evolving and predicts allele and genotype frequencies will remain constant.
Hardy Weinberg
This type of diagram shows the evolutionary relationships among species, often based on shared traits or genetic information.
phylogenetic tree
Which of these evolutionary agents is most consistent at causing populations to become better suited to their
environments over the course of generations?
A) Mutation
B) Non-random mating
C) Gene flow
D) Natural selection
E) Genetic drift
Natural Selection
The comparison of these body structures, which are similar in different species due to shared ancestry, provides evidence for evolution. Examples include the forelimbs of whales, bats, and humans.
Homologous Structures
When new species arise within the same geographic area, often due to differences in behavior, mating times, or resource use, this type of speciation occurs.
sympatric speciation
The equation p² + 2pq + q² = 1 is used to calculate the frequencies of these in a population.
genotypes
These are traits that are shared by two or more species and were inherited from a common ancestor, helping scientists determine evolutionary relationships.
homologous traits
Each of the following has a better chance of influencing gene frequencies in small populations than in large
populations, but which one most consistently requires a small population as a precondition for its occurrence?
A) Mutation
B) Non-random mating
C) Genetic drift
D) Natural selection
E) Gene flow
C GENETIC DRIFT
The study of these molecules, such as DNA and proteins, allows scientists to determine how closely related different species are by comparing genetic sequences.
molecular/biochemical evidence
This process occurs when members of two populations can no longer interbreed successfully, leading to the formation of separate species.
reproductive isolation
For a population to remain in Hardy-Weinberg equilibrium, this condition requires that all individuals have an equal chance of mating.
random mating
This type of trait evolves independently in unrelated lineages, often because of similar environmental pressures, and can confuse phylogenetic analyses.
analogous traits
Which type of selection is acting on this population, and how does it affect genetic diversity?
A) Stabilizing selection – decreases genetic diversity
B) Directional selection – shifts the population toward one extreme
C) Disruptive selection – increases genetic diversity
D) Balancing selection – maintains heterozygous advantage
C
These structures, which are no longer functional but were useful in ancestral species, provide evidence that organisms have evolved over time. Examples include human tailbones and whale pelvis bones.
Vestigial Structures
These are mechanisms that prevent mating or fertilization between species, such as differences in mating rituals, mating seasons, or incompatible gametes.
prezygotic barriers
This factor, which includes mutation, natural selection, gene flow, genetic drift, and non-random mating, will cause a population to deviate from Hardy-Weinberg equilibrium.
evolutionary forces
This method uses DNA, RNA, or protein sequences to estimate evolutionary relationships and the timing of divergence between species.
molecular phylogenetics
A population of beetles lives in a forest with both dark-colored and light-colored soil patches. Birds prey mostly on beetles that contrast with the soil they are on. Over generations, beetles that match their local soil color survive more often than mismatched beetles. This type of selection favors extremes over intermediates.
Disruptive selection
This type of evidence comes from studying the geographic distribution of species, which shows that closely related species often appear in nearby regions, while similar habitats on different continents are often occupied by unrelated species.
Biogeography
This type of speciation can occur rapidly in small populations due to intense selection and genetic drift, often following colonization of a new habitat or an environmental change.
punctuated equilibrium
In a population of 1000 individuals, the frequency of the recessive allele (q) is 0.3. Using the Hardy-Weinberg equation, calculate the expected number of heterozygous individuals in the population.
What is 420? (Calculation: p = 0.7, 2pq = 2 × 0.7 × 0.3 = 0.42; 0.42 × 1000 = 420 heterozygotes)
In phylogenetic analysis, this term refers to a group of organisms that includes an ancestor and all of its descendants, used to identify true evolutionary lineages.
clade or monophyletic group