Chapter 23 - Macroevolution Flashcards
What is continuous distribution?
A geographical distribution in which a species lives in suitable habitats throughout a geographical area.
What is macroevolution?
It is the larger-scale evolutionary changes observed in species and more inclusive groups. It results from the gradual accumulation of microevolutionary changes.
What is a disjunct distribution?
A geographical distribution in which populations of the same species or closely related species live in widely separated locations.
What is dispersal?
The movement of organisms away from their place of origin, which can then create disjunct distributions.
What is vicariance?
The fragmentation of a continuous geographical distribution by nonbiological factors, which can then create disjunct distributions.
What is convergent evolution?
The evolution of similar adaptations in distantly related organisms that occupy similar environments.
What is adaptive radiation?
A cluster of closely related species that are each adaptively specialized to a specific habitat or food source.
What is an adaptive zone?
An environment or part of an environment that may be occupied by a group of species exploiting resources in a similar manner.
What is extinction?
The death of the last individual in a species or the last species in a lineage.
What is background extinction rate?
The average rate of extinction of taxa through time.
What is the phyletic gradualism hypothesis?
The hypothesis that most morphological change occurs gradually over long periods of time.
What is the punctuated equilibrium hypothesis?
The evolutionary hypothesis that most morphological variation arises rapidly during speciation events in isolated populations at the edge of a species’ geographical distribution.
What is exaptation?
A trait that is adaptive in a context different from the context in which it originally evolved. Natural selection may then exaggerate or modify the trait to enhance its new function. Exaptations happen by chance.
What are homeotic genes?
Any of the family of genes that determines overall body plan during embryonic development.
