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Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together.
The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing. [6] [7] Crossbreeding between populations sometimes has positive effects on fitness-related traits, [8] but also sometimes leads to negative effects known as outbreeding ...
The extensive use of desirable individual animals at the exclusion of others can result in a popular sire effect. Selective breeding for dog breeds caused constricting breed-specific bottlenecks. [26] These bottlenecks have led to dogs having an average of 2–3% more genetic loading than gray wolves. [27]
Culling is: ... the rejection or removal of inferior individuals from breeding. The act of selective breeding. As used in the practice of breeding pedigree cats, this refers to the practice of spaying or neutering a kitten or cat that does not measure up to the show standard (or other standard being applied) for that breed.
A 1930s exhibit by the Eugenics Society.Some of the signs read "Healthy and Unhealthy Families", "Heredity as the Basis of Efficiency" and "Marry Wisely".Eugenics (/ j uː ˈ dʒ ɛ n ɪ k s / yoo-JEN-iks; from Ancient Greek εύ̃ (eû) ' good, well ' and -γενής (genḗs) ' born, come into being, growing/grown ') [1] is a set of beliefs and practices that aim to improve the genetic ...
The existence of limits in artificial selection experiments was discussed in the scientific literature in the 1940s or earlier. [1] The most obvious possible cause of reaching a limit (or plateau) when a population is under continued directional selection is that all of the additive-genetic variation (see additive genetic effects) related to that trait gets "used up" or fixed. [2]
An example of inbreeding depression is shown in the image. In this case, a is the recessive allele which has negative effects. In order for the a phenotype to become active, the gene must end up as homozygous aa because in the geneotype Aa, the A takes dominance over the a and the a does not have any effect. Some recessive genes result in ...
2 Effects. 3 In humans. 4 In non ... (also known as negative assortative mating ... but the evolution of selective forces involved in disassortative mating are still ...