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Gametic isolation [ edit ] The synchronous spawning of many species of coral in marine reefs means that inter-species hybridization can take place as the gametes of hundreds of individuals of tens of species are liberated into the same water at the same time.
Post-mating isolation occurs between the process of copulation (or pollination) and fertilization—also known as gametic isolation. [1]: 232 Some studies involving gametic isolation in Drosophila fruit flies, [93] ground crickets, [94] and Helianthus plants [95] suggest that there may be a role in ecology; however it is undetermined. [4]
An example of gametic isolation involves the allopatric sea urchins have minimal bindin differences (bindin is a protein involved in the process of sea urchin fertilization, used for species-specific recognition of the egg by the sperm) and have insufficient barriers to fertilization.
Before speciation is complete, two diverging populations may still produce viable offspring. As speciation progresses, isolating mechanisms – such as gametic incompatibility that renders fertilization of the egg impossible – are selected for in order to increase the reproductive divide between the two populations.
noncompetitive gametic isolation nondisjunction The failure of homologous chromosomes or sister chromatids to segregate properly during cell division. Nondisjunction results in daughter cells that are aneuploid, containing abnormal numbers of one or more specific chromosomes. It may be caused by any of a variety of factors. nongenetic barrier
Servedio and Noor include any detected increase in prezygotic isolation as reinforcement, as long as it is a response to selection against mating between two different species. [4] Coyne and Orr contend that, "true reinforcement is restricted to cases in which isolation is enhanced between taxa that can still exchange genes". [3]: 352
MHC-mediated mate choice may occur after copulation, at the gametic level, through sperm competition or female cryptic choice. The Atlantic salmon, Salmo salar, is one species in which sperm competition is influenced by the variation in the major histocompatibility complex, specifically that of the Class I alleles. Atlantic salmon males have ...
A gamete (/ ˈ ɡ æ m iː t /; from Ancient Greek γαμετή (gametḗ) 'wife', ultimately from Ancient Greek γάμος (gámos) 'marriage') is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. [1]