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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.
Charles Darwin demonstrates evolution by natural selection using many examples (1859). Louis Pasteur uses S-shaped flasks to prevent spores from contaminating broth. This disproves the theory of Spontaneous generation (1861) extending the rancid meat experiment of Francesco Redi (1668) to the micro scale.
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".
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.
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 ...
They come in all shapes and sizes. Some walk, some slither, some fly and some swim. Humans are blessed to share the planet with just over 2.1 million recognized species of animals. And scientists ...
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.
The causes are outlined in the following list: [12] [13] [4] Two types of experimental tests of ecological speciation caused by divergent environments. Experiment 1: a speciation event predicted to have occurred due to an ecologically-based divergent factor giving rise to two new species (1a). The experiment produces viable and fertile hybrid ...