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Related to Panmixia: panmictic



the free crossbreeding of individuals within a population or some other intraspecific group.

Complete panmixia exists only when each individual has the possibility to mate with any individual of the opposite sex. However, in nature pairs do not form for crossbreeding by chance. The choice of partners is conditioned chiefly by similarity in behavior and physiology; the partner chosen also inhabits the same part of the area of distribution. In the latter case, divergences from complete panmixia may be the result of crossbreeding between close relatives (inbreeding). Therefore, when one refers to panmixia in natural groups of individuals, and first and foremost in populations, what is usually meant is the extent to which panmixia occurs: it must be more common within a given group than among individuals of neighboring groups.

The extent to which panmixia occurs varies among species and depends on differences in the manner of reproduction. Some species form long-term, sometimes lifelong, pairs; other species form pairs only for the reproductive season. Some species, such as many galliforms, do not form lasting pairs; in other species, for example, many insects and arachnids, the females are fertilized only once in their lives. Species in which fertilization takes place externally, such as fishes and amphibians, do not form pairs. Here, a cluster of eggs from a single female may be fertilized by spermatozoa from different males. To whatever extent it occurs, panmixia safeguards the genetic and evolutionary unity of intraspecific groupings and of the species as a whole. The term “panmixia” was introduced in 1885 by A. Weismann.


Weismann, A. Die Continuität des Keimplasmas als Grundlage einer Theorie der Vererbung, 2nd ed. Jena, 1892.


References in periodicals archive ?
Esto estaria directamente relacionado con el exceso de homocigotos, el cual podria influir negativamente en el flujo genetico, y posiblemente aumentar el efecto de endogamia; situacion que sugiere una disminucion en los niveles de panmixia y con ello un incremento de consanguinidad en la poblacion.
2016) han demostrado estar en panmixia y por ende en equilibrio Hardy-Weinberg segun los analisis entre las frecuencias observadas y esperadas de los loci Orange y White Spotting, no obstante, un estudio realizado por Pena, et al.
El rapido crecimiento poblacional de la especie y el poco control humano sobre su reproduccion, incrementa considerablemente el flujo genetico y la panmixia, condiciones claves para mantener al minimo la variacion en las frecuencias geneticas.
In comparison to temperate monopopulation species, the large distribution and the taxonomy of this species question the number of its spawning areas, its panmixia within each subspecies and the differentiation between them.
The total gene diversity was calculated as the average diversity over all loci (assuming panmixia, genetic diversity is equivalent to the expected heterozygosity He).
The statistical rejection of panmixia within the WA improves our understanding of bowhead whale biology, and the lack of evidence for multiple populations within the WA enables risk-averse management of aboriginal hunting of Western Arctic bowhead whales.
Regression, Heredity and Panmixia. Philosophical Transactions of the Royal Society of London, 187:253-318, 1896.
Si hubiera panmixia entre las especies parentales en las poblaciones simpatricas, se darian las condiciones para que actue el principio de "exclusion del citotipo minoritario" (LEVIN, Taxon 24: 35-43.
Most EAs use a single population (panmixia) of individuals and apply operators on them as a whole.
Inbreeding coefficients ([]) indicated deviation from panmixia. The values ranged from -0.050 for IDHP-1* to 0.772 for ACP*.
Furthermore, probability models, by themselves, do not designate appropriate mating and reproductive systems such as cross-pollination (panmixia), mixed self and random mating, full-sibs (chain crosses and paired plant crosses), half-sibs (random pollen pollination), and self-fertilization, that could, under specific circumstances, maximize the genetic representativeness of a sample.