Chapter 23
This is the change in allele frequencies due to random chance, especially in small populations.
What is genetic drift?
Biologists commonly use three criteria to define species: biological, morphospecies, and ______ species concepts.
What is the phylogenetic species concept?
The branching evolutionary history of a group of organisms is called this.
What is a phylogeny?
When females choose mates or males compete for mates, this type of nonrandom mating occurs.
What is sexual selection? Chapter 23
A sudden decrease in population size due to disease or catastrophe that reduces allelic diversity is called this.
What is a population bottleneck? Chapter 23
In peacocks, the long, colorful tail is explained by this form of selection.
What is intersexual selection (mate choice)?
his term describes the splitting event that creates two or more distinct species from an ancestral species.
What is speciation?
The study of where species and populations are distributed geographically is called this.
What is biogeography?
The asteroid impact 66 million years ago that wiped out most dinosaurs marks this extinction.
What is the End-Cretaceous extinction? Chapter 25
A geographic area where interbreeding between two species occurs and hybrids are common is called this.
What is a hybrid zone? Chapter 24
This type of selection favors one extreme phenotype and reduces genetic diversity.
What is directional selection?
This type of allopatric speciation occurs when a group moves to a new area and establishes a new population.
What is dispersal?
A group that includes an ancestral species and some but not all of its descendants is called this.
What is a paraphyletic group?
This selection maintains genetic variation in a population, often through heterozygote advantage or frequency-dependent selection.
What is balancing selection? Chapter 23
Fossilization requires rapid burial and slow decomposition, making it this type of event.
What is rare? Chapter 25
This selection favors extreme phenotypes over intermediate ones.
What is disruptive selection?
When natural selection reduces mating between overlapping species, this outcome occurs.
What is reinforcement?
This type of evolution produces analogous traits in distantly related organisms due to similar environmental pressures.
What is convergent evolution?
A group that does not include the most recent common ancestor of its members is called this.
What is a polyphyletic group? Chapter 25
Polyploidy, an internal event leading to reproductive isolation, is most common in these organisms.
What are plants? Chapter 24
When a small group colonizes a new area and allele frequencies differ from the source population, this effect occurs.
What is the founder effect?
When two species hybridize and produce a new, viable polyploid species, this occurs.
What is allopolyploidy?
Human-driven habitat loss, climate change, and overfishing are contributing to this modern extinction event.
What is the 6th mass extinction (Anthropocene extinction)?
A sudden geographic barrier, like a river forming, can lead to this type of allopatric speciation.
What is vicariance? Chapter 24
Closely related taxa are depicted
as _____ that share a
recent common ancestor.
What are sister groups? Chapter 25