Category: Genetics stubs Population genetics is the study of the distribution of and change in allele frequencies under the influence of the four evolutionary forces: natural selection, genetic drift, mutation, and migration. ... Hardy–Weinberg principle for two alleles: the horizontal axis shows the two allele frequencies p and q, the vertical axis shows the genotype frequencies and the three possible genotypes are represented by the different glyphs The Hardy–Weinberg principle (HWP) (also Hardy–Weinberg equilibrium (HWE), or Hardy–Weinberg law) states... Linkage disequilibrium (LD) is the non-random association of alleles at two or more loci on a chromosome. ... In population genetics, Ronald Fishers fundamental theorem of natural selection was originally stated as: The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time. ... The neutral theory of molecular evolution (also, simply the neutral theory of evolution) is an influential theory that was introduced with provocative effect by Motoo Kimura in the late 1960s and early 1970s. ... Selection is hierachically classified into natural and artificial selection. ... Natural selection is the metaphor Charles Darwin used in 1859 to name the process he postulated to drive the adaptation of organisms to their environments and the origin of new species. ... Illustration from The Descent of Man and Selection in Relation to Sex by Charles Darwin showing the Tufted Coquette Lophornis ornatus, female on left, ornamented male on right. ... This Chihuahua mix and Great Dane show the wide range of dog breed sizes created using artificial selection. ... Ecological selection (or environmental selection or survival selection or individual selection or asexual selection) refers to natural selection minus sexual selection, i. ... Genetic drift is a contributing factor in biological evolution, in which traits which do not affect reproductive fitness change in a population over time. ... Species with a small population size are subject to a higher chance of extinction because their small population size makes them more vulnerable to genetic drift, resulting in stochastic variation in their gene pool, their demography and their environment. ... A population bottleneck (or genetic bottleneck) is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing, and the population is reduced by 50% or more, often by several orders of magnitude. ... The founder effect is an evolutionary phenomenon. ... Sir Ronald Fisher Sir Ronald Aylmer Fisher, FRS (17 February 1890 – 29 July 1962) was a British eugenicist, evolutionary biologist, geneticist and statistician. ... John Burdon Sanderson Haldane (November 5, 1892 - December 1, 1964), who normally used J.B.S. as a first name, was a geneticist born in Scotland and educated at Eton and Oxford University. ... Sewall Green Wright (December 21, 1889– March 3, 1988) was an American geneticist known for his influential work on evolutionary theory. ... A speculative phylogenetic tree of all living things, based on rRNA gene data, showing the separation of the three domains, bacteria, archaea, and eukaryotes. ... Microevolution is the occurrence of small-scale changes in gene frequencies in a population, over a few generations, also known as change at or below the species level. ... Evolutionary game theory (EGT) is the application of game theory in evolutionary biology. ... In evolutionary biology, fitness landscapes or adaptive landscapes are used to visualize the relationship between genotypes (or phenotypes) and replicatory success. ... This is a list of topics in evolutionary biology and evolution. ...