from The American Heritage® Dictionary of the English Language, 4th Edition
- n. One member of a pair or series of genes that occupy a specific position on a specific chromosome.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. One of a number of alternative forms of the same gene occupying a given position on a chromosome.
from the GNU version of the Collaborative International Dictionary of English
- n. one of two or more alternative forms of a gene that can have the same place on homologous chromosomes and are responsible for alternative traits.
- n. either of a pair of Mendelian characters that may occur in an organism as a consequence of variation at one gene locus.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (genetics) either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character
Evolution is about one thing: The explanation for the changes in allele frequencies over time.
The allele could originate by mutation of an allele for brown fur and the environment caused selection which caused a change in allele frequency.
The mechanisms whereby genomes are reduced or expanded are often not the standard "neo-Darwinian processes", ie changes in allele frequency.
Mesk, when you suggest that an allele is conserved if it has 0. 0001% advantage, you are comparing apples to oranges in this case, are you not?
If you did it with 5,000 mutants and 5,000 wild-types (enough to detect a selective advantage as small as 0.005%) and saw changes in allele frequency compatible with drift, people would definitely stand up and take notice.
With interesting applications here for diagnosis, therapy models and possibly even pharmaceuticals, the authors concluded that "the absence of this protective bias in short-allele carriers is likely to be linked with the heightened susceptibility to mood disorders such as depression and anxiety that has been reported in this group."
(An allele is any of the variants of a gene that takes more than one form; such genes are known as polymorphisms.
It is possible that in the nomadic setting, a boy with this allele might be able to more effectively defend livestock against raiders or locate food and water sources, but that the same tendencies might not be as beneficial in settled pursuits such as focusing in school, farming or selling goods.
Watson had a variant called *10, associated with lower activity and found in fewer than 1 percent of Caucasians, whereas Venter had the more active *1 variant, technically known as an allele.
His findings: In all five genes, I have a variant, or allele, that is sometimes associated with bad investing decisions.