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Animal coloration, readily observable, soon provided strong and independent lines of evidence, from camouflage, mimicry and aposematism, that natural selection was indeed at work. [ 6 ] [ 7 ] [ 8 ] The historian of science Peter J. Bowler wrote that Darwin's theory "was also extended to the broader topics of protective resemblances and mimicry ...
A simplification of an allopatric speciation experiment where two lines of fruit flies are raised on maltose and starch media. Laboratory experiments of speciation have been conducted for all four modes of speciation: allopatric, peripatric, parapatric, and sympatric; and various other processes involving speciation: hybridization, reinforcement, founder effects, among others.
The term natural selection is most often defined to operate on heritable traits, because these directly participate in evolution. However, natural selection is "blind" in the sense that changes in phenotype can give a reproductive advantage regardless of whether or not the trait is heritable.
Belyayev chose the silver fox for his experiment, "because it is a social animal and is related to the dog." [ 8 ] The silver fox had, however, never before been domesticated. Belyayev designed a selective-breeding program for the foxes that was intended to reproduce a single major factor, namely "a strong selection pressure for tamability".
Unwittingly, humans have carried out evolution experiments for as long as they have been domesticating plants and animals. Selective breeding of plants and animals has led to varieties that differ dramatically from their original wild-type ancestors. Examples are the cabbage varieties, maize, or the large number of different dog breeds.
[54] The experiment became the largest ever in the study of industrial melanism, involving 4,864 individuals in a six-year investigation, and it confirmed that melanism in moths is a genuine example of natural selection involving camouflage and predation. Their concluding remark runs: "These data provide the most direct evidence yet to ...
Selection against hybrids can sometimes (it is possible that nonecological speciation can be attributed) be considered a form of ecological isolation if it originates from an ecological mechanism. [4] For example, the hybrid offspring may be seen as "less attractive" to mates due to intermediate sexual displays or differences in sexual ...
There are over 800 described species, and according to estimates, there could be well over 1,600 species in the region. Their evolution is cited as an example of both natural and sexual selection. [40] [41] A 2008 study suggests that sympatric speciation has occurred in Tennessee cave salamanders. [42]