Information AboutGenotype-phenotype Distinction |
| CATEGORIES ABOUT GENOTYPE-PHENOTYPE DISTINCTION | |
| genetics | |
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The Mapping of a set of genotypes to a set of phenotypes is sometimes referred to as the genotype-phenotype map. An organism's genotype is a major (the largest by far for Morphology ) influencing factor in the development of its phenotype, but it is not the only one. Even two organisms with identical genotypes normally differ in their phenotypes. One experiences this in everyday life with Monozygous (i.e. Identical) Twins . Identical twins share the same genotype, since their genomes are identical; but they never have the same phenotype, although their phenotypes may be very similar. This is apparent in the fact that their mothers and close friends can always tell them apart, even though others might not be able to see the subtle differences. Further, identical twins can be distinguished by their Fingerprint s, which are never completely identical. The concept of s such as Dragonflies , they develop larger heads and tails relative to their body size and display darker Pigmentation . Larvae with these traits have a higher chance of Survival when exposed to the predators, but grow more slowly than other phenotypes. In contrast to phenotypic plasticity, the concept of Genetic Canalization addresses the extent to which an organism's phenotype allows conclusions about its genotype. A phenotype is said to be canalized if Mutation s (changes in the genome) do not noticeably affect the physical properties of the organism. This means that a canalized phenotype may form from a large variety of different genotypes, in which case it is not possible to exactly predict the genotype from knowledge of the phenotype (i.e. the genotype-phenotype map is not invertible). If canalization is not present, small changes in the genome have an immediate effect on the phenotype that develops. The terms "genotype" and "phenotype" were created by Wilhelm Johannsen in 1911. SEE ALSO BIBLIOGRAPHY #J. Van Buskirk and B. R. Schmidt, "Predator-induced Phenotypic Plasticity in Larval Newts: Trade-offs, Selection, and Variation in Nature," ''Ecology'' 81 (2000): 3009-3028. EXTERNAL LINKS ''An earlier version of this article was posted on Nupedia .'' |
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