Evolution Foundations
This term, used by Darwin, summarizes the idea that species accumulate differences from their ancestors over time.
What is “descent with modification”?
A group of interbreeding members of the same species living in the same area is called this.
What is a population?
The idea that life arose from non-living material during Earth’s early history is known as this.
What is abiogenesis?
These are inherited characteristics that enhance survival and reproduction in specific environments.
What are adaptations?
When interacting species evolve in response to each other, such as flowers and pollinators, this process occurs.
What is coevolution?
This process, in which humans choose desirable traits in plants and animals, inspired Darwin’s ideas about natural selection.
What is artificial selection?
These random changes in DNA are the source of new alleles and all genetic variation.
What are mutations?
The endosymbiotic theory explains the origin of these two eukaryotic organelles.
What are mitochondria and chloroplasts?
The movement of alleles into or out of populations is known as this evolutionary mechanism.
What is gene flow?
This mass extinction, linked to Siberian volcanism, wiped out ~96% of marine species.
What is the Permian extinction?
Structures like the forelimbs of mammals, which share underlying similarity due to common ancestry, are called this.
What are homologous structures?
This pattern of evolution, supported by fossil evidence, suggests long periods of stability interrupted by rapid change.
What is punctuated equilibrium?
The appearance of many major animal groups within a short period of geologic time is known as this evolutionary event.
What is the Cambrian explosion?
This form of natural selection favors individuals at one extreme of the trait distribution.
What is directional selection?
In genetic drift, this specific effect occurs when a large population suddenly reduces in size due to an environmental event, dramatically altering allele frequencies.
What is the bottleneck effect?
The similarity of DNA sequences across distantly related species provides this type of evolutionary evidence.
What is molecular homology?
This type of evolution results in similar traits in distantly related organisms due to similar environmental pressures, not shared ancestry.
What is convergent evolution?
A trait that provides no immediate advantage or disadvantage is known as this type of genetic variation.
What is neutral?
In a phylogenetic tree, this term refers to a lineage that diverges early and remains unbranched compared to others.
What is a basal taxon?
Lamarck proposed these two mechanisms to explain evolutionary change.
What are use & disuse and inheritance of acquired characteristics?
This term describes traits that look similar and serve similar functions but do not arise from a common ancestor.
What are analogous structures?
This mechanism of evolution occurs when chance events cause unpredictable allele frequency changes.
What is genetic drift?
In a phylogenetic tree, this term refers to two taxa that share an immediate common ancestor.
What are sister taxa?
Gene flow generally increases genetic variation within a population but decreases this type of variation between populations.
What is genetic differentiation (or differences in allele frequencies)?
Name the five conditions required for a population to remain in Hardy-Weinberg equilibrium for a particular trait.
What are: (1) no mutations, (2) random mating, (3) large population size, (4) no gene flow, and (5) no natural selection?