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Hybrid incompatibility occurs when the offspring of two closely related species are not viable or suffer from infertility. Charles Darwin posited that hybrid incompatibility is not a product of natural selection, stating that the phenomenon is an outcome of the hybridizing species diverging, rather than something that is directly acted upon by selective pressures. [4]
A mule is a sterile hybrid of a male donkey and a female horse.Mules are smaller than horses but stronger than donkeys, making them useful as pack animals.. In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction.
This is a list of genetic hybrids which is limited to well documented cases of animals of differing species able to create hybrid offspring which may or may not be infertile. Hybrids should not be confused with genetic chimeras , such as that between sheep and goat known as the geep .
The sterility of many interspecific hybrids in angiosperms has been widely recognised and studied. [33] Interspecific sterility of hybrids in plants has multiple possible causes. These may be genetic, related to the genomes, or the interaction between nuclear and cytoplasmic factors, as will be discussed in the corresponding section.
Hybrid speciation is a form of speciation where hybridization between two different species leads to a new species, reproductively isolated from the parent species. Previously, reproductive isolation between two species and their parents was thought to be particularly difficult to achieve, and thus hybrid species were thought to be very rare.
In humans, barring intersex conditions causing aneuploidy and other unusual states, it is the male that is heterogametic, with XY sex chromosomes.. Haldane's rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J. B. S. Haldane, that states that if — in a species hybrid — only one sex is inviable or sterile, that sex is more ...
Genetic incompatibility describes the process by which mating yields offspring that are nonviable, prone to disease, or genetically defective in some way. In nature, animals can ill afford to devote costly resources for little or no reward, ergo, mating strategies have evolved to allow females to choose or otherwise determine mates which are more likely to result in viable offspring.
Most often, the hybrid embryo dies before birth. However, sometimes, the offspring develops fully with mixed traits, forming a frail, often infertile adult. [2] This hybrid displays reduced fitness, marked by decreased rates of survival and reproduction relative to the parent species. The offspring fails to compete with purebred individuals ...