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In the off-spring of crosses between Drosophila simulans and its island derivative Drosophila mauritiana, female hybrids are fertile but male hybrids are sterile. Recent studies have shown that a critical gene for gender determination in Drosophila known as the sex-lethal gene is highly misregulated in D. melanogaster and D. simulans hybrids ...
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.
The hybrids between both species are not sterile, in the sense that they produce viable gametes, ovules and spermatozoa. However, they cannot produce offspring as the sperm of the hybrid male do not survive in the semen receptors of the females, be they hybrids or from the parent lines.
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 hybrid between a Bengal tiger and a Siberian tiger is an example of an intra-specific hybrid. Family Canidae. Fertile canid hybrids occur between coyotes, wolves, dingoes, jackals and domestic dogs. Hybrids of unknown fertility can occur between South American foxes of the Lycalopex genus and domestic dogs. Family Mustelidae
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 ...
Fused protoplast (left) with chloroplasts (from a leaf cell) and coloured vacuole (from a petal) Somatic fusion, also called protoplast fusion, is a type of genetic modification in plants by which two distinct species of plants are fused together to form a new hybrid plant with the characteristics of both, a somatic hybrid. [1]
Sterile F1 hybrids have given rise to allopolyploids in other taxa (e.g. Spartina and Senecio), but allopolyploids can also form via fertile intermediate hybrids (e.g. Tragopogon). In general, hybrid species can arise from two major types of hybrid speciation, defined by whether the speciation event is associated with genome duplication ...