Exam 3 - Biogeography

Refers to speciation that occurs within a spatially contiguous population, as in the case of the Anthoxanthum grass

Parapatric speciation

Transfer of genetic material between populations

Gene flow

Change in the gene frequency of a population caused solely by chance

Genetic drift

When a certain species does not occur in a particular locality where it formerly did, but still does occur in other areas

Extirpated

The process of diversifying from an ancestral taxon into many new forms, especially after a change in the environment

Adaptive radiation

Differential survival and/or reproduction of organisms due to hereditary characteristics

Natural selection

A species that only occurs in one area and nowhere else

Endemic species

Complete elimination of a species from the planet

Extinction

Term for rapid evolution. Has been in some fossils just after speciation, rapid evolution, then litter change for a long time

Punctuated equilibrium

The most major extinction event in which ~95% of marine animals went extinct

Permian-Triassic

Refers to the speciation that occurs when populations physically or geographically separated

Allopatric speciation

Name two ways in which allopatric speciation can occur:

Peripheral isolates and vicariance

Term for slow evolution, meaning it changes slowly, and gradually over time

Gradualism

Refers to speciation that can occur within a population and there is no physical barrier

Sympatric speciation

Name two ways in which sympatric speciation can occur:

Polyploidy and disruptive selection

The type of evolution that demonstrates small changes in genetic makeup of a population and can be due to natural selection, mutations, genetic drift, and/or gene flow

Microevolution

The type of evolution that demonstrates large changes in genetic makeup of a population, including speciation

Macroevolution

List any FIVE intrinsic features/habitats of species that make them more likely to go extinct

Narrow geographic range. One or few populations. Small population size. Low genetic variability. Specialized niche requirements.

Biological species concept

A species is a group of organisms that naturally interbreeds and produces fertile offspring, resulting in reproductive isolation

Strength of biological species concept

It is testable and based on reproductive isolation, explaining how species maintain boundaries

Limitation of biological species concept

It cannot be used for fossils or asexual species. Difficult to use for geographically isolated or hybridizing populations.