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Bottom (Graph 3) represents disruptive selection with both extremes being favored. In population genetics, directional selection is a type of natural selection in which one extreme phenotype is favored over both the other extreme and moderate phenotypes. This genetic selection causes the allele frequency to shift toward the chosen extreme over ...
These charts depict the different types of genetic selection. On each graph, the x-axis variable is the type of phenotypic trait and the y-axis variable is the amount of organisms. Group A is the original population and Group B is the population after selection. Graph 1 shows directional selection, in which a single extreme phenotype is favored.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which is ...
Stabilizing selection. 1: directional selection: a single extreme phenotype favoured. 2, stabilizing selection: intermediate favoured over extremes. 3: disruptive selection: extremes favoured over intermediate. Stabilizing selection (not to be confused with negative or purifying selection [1] [2]) is a type of natural selection in which the ...
Blackcocks at the Lek watercolour and bodycolour by Archibald Thorburn, 1901. Group selection is a proposed mechanism of evolution in which natural selection acts at the level of the group, instead of at the level of the individual or gene. Early authors such as V. C. Wynne-Edwards and Konrad Lorenz argued that the behavior of animals could ...
Sexual selection in humans concerns the concept of sexual selection, introduced by Charles Darwin as an element of his theory of natural selection, [1] as it affects humans. Sexual selection is a biological way one sex chooses a mate for the best reproductive success. Most compete with others of the same sex for the best mate to contribute ...
Kin selection. The co-operative behaviour of social insects like the honey bee can be explained by kin selection. Kin selection is a process whereby natural selection favours a trait due to its positive effects on the reproductive success of an organism's relatives, even when at a cost to the organism's own survival and reproduction. [1]
In behavioral ecology, negative frequency-dependent selection often maintains multiple behavioral strategies within a species. A classic example is the Hawk-Dove model of interactions among individuals in a population. In a population with two traits A and B, being one form is better when most members are the other form.