Genetic structure
Encyclopedia
Genetic structure refers to any pattern in the genetic
makeup of individuals within a population.
In the absence of genetic structure, one can infer little to nothing about the genetic makeup of an individual by studying other members of the population. When genetic structure is present, on the other hand, much can be inferred.
In trivial terms, all populations have genetic structure, because all populations can be characterised by their genotype
or allele
frequencies: if only 1% of a large sample of moths
drawn from a single population have spotted wings, then it is safe to assume that any unknown individual is unlikely to have spotted wings.
A more complicated example arises in dense thicket
s of plants, where plants tend to be pollinated
by near neighbours, and seed
s tend to fall and germinate
near the maternal plant. In such a scenario, plants tend to be more closely related to nearby plants than they are to distant plants; and yet they are more likely to breed with nearby plants than they are with distant plants. Thus an inbreeding cycle is created that perpetuates the pattern of plants being closely related to near neighbours. This is a form of genetic structure because one can infer much about the genetic makeup of any individual plant simply by studying plants in its immediately neighbourhood.
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
makeup of individuals within a population.
In the absence of genetic structure, one can infer little to nothing about the genetic makeup of an individual by studying other members of the population. When genetic structure is present, on the other hand, much can be inferred.
In trivial terms, all populations have genetic structure, because all populations can be characterised by their genotype
Genotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...
or allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
frequencies: if only 1% of a large sample of moths
Moths
Moths may refer to:* Gustav Moths , German rower* The Moths!, an English indie rock band* MOTHS, members of the Memorable Order of Tin Hats...
drawn from a single population have spotted wings, then it is safe to assume that any unknown individual is unlikely to have spotted wings.
A more complicated example arises in dense thicket
Thicket
A thicket is a very dense stand of trees or tall shrubs, often dominated by only one or a few species, to the exclusion of all others. They may be formed by species that shed large amounts of highly viable seeds that are able to germinate in the shelter of the maternal plants.In some conditions the...
s of plants, where plants tend to be pollinated
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
by near neighbours, and seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s tend to fall and germinate
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
near the maternal plant. In such a scenario, plants tend to be more closely related to nearby plants than they are to distant plants; and yet they are more likely to breed with nearby plants than they are with distant plants. Thus an inbreeding cycle is created that perpetuates the pattern of plants being closely related to near neighbours. This is a form of genetic structure because one can infer much about the genetic makeup of any individual plant simply by studying plants in its immediately neighbourhood.