Glossary

Adaptive radiation: evolutionary response to large-scale environmental change. This results in the formation of new ecological niches that can be occupied through the adaptation of previous generalists.

Allopatric speciation: speciation as a result of physical separation of the parent population into isolated groups. Cladistics: approach to classification based on the evolutionary history of organisms in terms of shared, derived characteristics. Cladogram: branching diagram that describes the taxonomic relationships based on the principles of cladistics. Codons: groups of three of the four molecules that make up DNA. They make up the letters of the genetic code. DNA (deoxyribonucleic acid): double-stranded nucleic acid that contains genetic information. Genome: an organism's complete genetic material. Mass extinction: extinction of numerous species (greater than 10% of families or 40% of species) over a short time period. Molecular clocks: comparison of the rates of structural change in indicator molecules in different species.

Mutation: change in the DNA of genes that ultimately causes genetic diversity.

Natural selection: differential selection of organisms. Favorable adaptations are incorporated in the genome of the next generation, increasing its competitive ability. Phyletic gradualism: theory that evolution is gradual at a more or less constant rate. Speciation occurs as part of this gradual change.

Phylogeny: complete evolutionary history of a species or a group of related species.

Punctuated equilibrium: theory that periods of evolutionary equilibrium are interrupted by episodes of rapid evolutionary change.

Species: a population of organisms that has similar anatomical characteristics and interbreeds.

Sympatric speciation: speciation as a result of changes in lifestyle preferences within a population.

Was this article helpful?

0 0
Survival Basics

Survival Basics

This is common knowledge that disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

Get My Free Ebook


Post a comment