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Found Speciation 14 times.

Displaying results 1 to 10.

1. Allopatric speciation (geographic speciation)
The evolutionary process through which two geographically separated (and therefore non-interbreeding) population s of the same species become less and less similar to each other over time (via mutation or the success of different traits in each environment) and eventually become distinctly different species.

2. Allopatrically
An adverb refering to a specific mechanism of evolutionary divergence. A species which arose allopatrically from another diverged from the other because of evolutionary changes occurring in two different geographically separated populations. Also see allopatric and speciation .

3. Genetic divergence
The separation of a population's gene pool from the gene pools of other populations due to mutation , genetic drift, and selection. Continued divergence can lead to speciation.

4. Genetic drift
The random change of the occurrence of a particular gene in a population ; genetic drift is thought to be one cause of speciation when a group of organisms is separated from its parent population.

5. Macroevolution (adj. macroevolutionary)
Evolution on a species level ( speciation and extinction ) and at higher taxonomic classifications (appearance and disappearance of genus es, families, order s, etc.).

6. Out of Africa hypothesis
Holds that modern human populations (Homo sapiens) are all derived from a single speciation event that took place in a restricted region in Africa.

7. Parapatric speciation
The evolutionary process of a single population of a species splitting into two or more species, where the new species end up in areas that are right next to each other (but not overlapping) and which do not have any geographic barriers in between. Parapatric speciation is intermediate between allopatric and sympatric speciation.

8. Polyploidy
Abnormal variation in the number of chromosome sets. The condition when a cell or organism has more than the customary two sets of chromosomes. This is an especially effective speciation mechanism in plants since the extra chromosomes will establish reproductive isolation with the parental population(s), an essential for speciation.

9. Punctuated equilibrium
A model that holds that the evolutionary process is characterized by long periods with little or no change interspersed with short periods of rapid speciation.

10. Quantum models of speciation
Models of evolution that hold that speciation sometimes occurs rapidly as well as over long periods, as the classical theory proposed.


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