Search results
Results From The WOW.Com Content Network
Autosomal dominant and autosomal recessive inheritance, the two most common Mendelian inheritance patterns. An autosome is any chromosome other than a sex chromosome.. In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome.
In genetics, underdominance, also known as homozygote advantage, heterozygote disadvantage, or negative overdominance," [1] is the opposite of overdominance.It is the selection against the heterozygote, causing disruptive selection [2] and divergent genotypes.
Dominance is not an inherent property of any allele or phenotype, but simply describes its relationship to one or more other alleles or phenotypes; it is possible for one allele to be simultaneously dominant over a second allele, recessive to a third, and codominant to a fourth. In genetics shorthand, dominant alleles are often represented by a ...
The idea of sex-limited genes was initially developed by Charles Darwin in 1871 in his book The Descent of Man and Selection in Relation to Sex. [6] He did not distinguish between sex-limited, sex-linked, and sex-influenced genes, but referred to any gene that expresses differently between sexes as sex-limited.
Pseudodominance is the situation in which the inheritance of a recessive trait mimics a dominant pattern. [1]Normally, two recessive alleles need to be inherited (one from each parent) for the recessive trait to be expressed but recessive merely means that the trait is only expressed in the absence of the dominant alleles.
The Genetical Theory of Natural Selection is a book by Ronald Fisher which combines Mendelian genetics with Charles Darwin's theory of natural selection, [1] with Fisher being the first to argue that "Mendelism therefore validates Darwinism" [2] and stating with regard to mutations that "The vast majority of large mutations are deleterious; small mutations are both far more frequent and more ...
The work of Fisher, Haldane and Wright founded the discipline of population genetics. This integrated natural selection with Mendelian genetics, which was the critical first step in developing a unified theory of how evolution worked. [4] [5] John Maynard Smith was Haldane's pupil, whilst W. D. Hamilton was influenced by the writings of Fisher.
Where the heterozygote is indistinguishable from one of the homozygotes, the allele expressed is the one that leads to the "dominant" phenotype, [9] [10] and the other allele is said to be "recessive". The degree and pattern of dominance varies among loci. This type of interaction was first formally-described by Gregor Mendel.