Natural selection of heterogeneous environments, Biology

While describing normalising selection it was said that in uniform environments selection limits the variability of populations and evolves a genetic homeostasis. The type of selection process that is in progress in heterogeneous environments is known as diversifying selection.

Diversifying selection is the converse of normalising selection. Let us assume that a population occupying a certain environment, has two or more groups of genotypes (AA, Aa and aa) and meets two or more sub-environments or habitats. Among the two or more genotypes, let us say that a rare genotype (aa) that is well adapted to its habitat will be promoted by selection and the frequency of that genotype will increase as long as the habitat is not fully occupied. But when the habitat is saturated, no further increase in the frequency of that genotype an be observed. It is quite likely that the excess population could spill over to another sub-environment. The genotype may not be completely adapted to the new habitat and it is here that diversifying selection plays a role so as to establish a population consisting different genotypes. The phenomenon where two or more genotypes for a given trait exkt in a population is called genetic polymorphism. The different sub-environments co'me to be occupied by different genotypes and such an occupation would be as complete and efficient as possible.

Posted Date: 4/6/2013 1:42:03 AM | Location : United States







Related Discussions:- Natural selection of heterogeneous environments, Assignment Help, Ask Question on Natural selection of heterogeneous environments, Get Answer, Expert's Help, Natural selection of heterogeneous environments Discussions

Write discussion on Natural selection of heterogeneous environments
Your posts are moderated
Related Questions
Q. What are the main prophylactic measures against schistosomiasis? The major measures to prevent schistosomiasis are information for infected individuals to look for treatment


Compilations- Non-assurance Engagements Within a compilation engagement, such the accountant is engaged to need accounting expertise that opposed to auditing expertise to brin

What are the infructescences, pseudofruits and parthenocarpic fruits? The Infructescences are aggregated fruits formed from inflorescences, aggregated flowers. Grape clusters a

Question Write a short note on the following: 1 Gram staining 2 Embden-Meyerhoff-Parnas pathway 3 Interferons 4 Probiotics 5 Pasteurization 6 Endospores

Q. What is Atomic constipation? This type is most common; often it is called the "lazy .bowel". There is a loss of muscle tone causing weak peristalsis, the causes are: a) L

Conventional Endodontic Treatment Surgical Endodontic & Retrograde sealing of Immature root Apex: After cleaning and shaping of the RC and before filling , I make a surgical

Which of the following is true for a toe motor neuron that excites a toe muscle that moves the big toe in the left foot? A. All of the axon terminals of the toe motor neuron ar

RECIPROCAL CROSSES Similar results were obtained with reciprocal crosses also. A reciprocal crosses involves the same traits but carried by sexes opposite to those in the origi

Syphilis and HIV Most clinicians treat HIV-infected patients with syphilis and normal CSF with standard penicillin doses for the stage of syphilis, but some patients may need