Coalescence (genetics)
From Wikipedia, the free encyclopedia
- For other uses, see Coalescence (disambiguation).
Coalescence describes the idea that any sample of genetic sequences from any number of living things (that is, bacteria, archaea and eukaryotes) can be traced back to a common ancestor in the past. Due to random elimination of ancient genetic lineages, with constant population size of the taxons considered, the most recent common ancestor (MRCA) remains at a constant time distance from the present.
Coalescent theory describes the population genetics probabilistic theory that studies coalescence times for genes and alleles under genetic drift. In the absence of any type of natural selection coalescence times can be estimated by straightforward applications of probability. However, coalescence is impeded by balancing selection and is difficult to analyze for gene loci that are under selection.
[edit] External links
- EvoMath 3: Genetic Drift and Coalescence, Briefly - overview, with probability equations for genetic drift, and simulation graphs
Topics in population genetics
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| Key concepts: Hardy-Weinberg law | genetic linkage | linkage disequilibrium | Fisher's fundamental theorem | neutral theory |
| Selection: natural | sexual | artificial | ecological |
| Effects of selection on genomic variation: genetic hitchhiking | background selection |
| Genetic drift: small population size | population bottleneck | founder effect | coalescence |
| Founders: R.A. Fisher | J.B.S. Haldane | Sewall Wright |
| Related topics: evolution | microevolution | evolutionary game theory | fitness landscape | genetic genealogy |
| List of evolutionary biology topics |
