Expression of variability, Biology

Assignment Help:

In the preceding section we emphasised the fact that cvolution or the continuous adaptations to the environment can take place only when pheiiotypes exhibit variability. In the absense of variability, the chances arc that existing living organisms would become extinct since with the change in the environment these organisms would die without leaving progeny. Fortunatcly in living systems mutations and recombinations generate the required variability. However, organisms often strive to arrive at populations which are more or less uniform. This is possible because selection process acts in such a way that a certain degree of uniformity of phenotype is imposed among individuals of n population. If an individual were to be vcry different in some way from thc rest of the population. he would be less well adapted to the environment as compared to other members of the population and therefore unable to compete successfully with them. However, in a continuously changing environment, a slight phenotypic variability should be maintained in a population. In a changing environment no phenotype remains optimally adapted for long. This is the precise reason why variability needs to be generated continuously in a population and used to develop adaptations in the way Darwin suggested. We shall look into the mechanisms that generate variability.


Related Discussions:- Expression of variability

Pisces, what is the mode of nutrition in pisces

what is the mode of nutrition in pisces

Explain adverse effects of famciclovir, Adverse Effects of Famciclovir ...

Adverse Effects of Famciclovir Famciclovir has been generally well tolerated. Headache, nausea and diarrhea have been reported. Like acyclovir, famciclovir has been associated

Which is the kind of nitrogen waste birds produce, Q Which is the kind of n...

Q Which is the kind of nitrogen waste birds produce? Why does this feature, besides being an adaptation to the terrestrial environment, also mean an adaptation to flight? Birds

Show the principles of prevention of diabetes mellitus, Q. Show the Princip...

Q. Show the Principles of Prevention of diabetes mellitus? Principles of primary prevention of diabetes are:     Creating awareness of diabetes mellitus   Identifying Pre-D

Polytene chromosomes, PO L YTEN E CHROMOSOMES First seen by Balb...

PO L YTEN E CHROMOSOMES First seen by Balbiani in salivary glands of larva of Chironomus insect (belongs to order Diptera). Later on such chromosomes observed in severa

Do membranes form only the outer wrapping of cells, Normal 0 fa...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the mechanism of gap junctions, What is the mechanism by which gap ...

What is the mechanism by which gap junctions could relay signals from G protein coupled receptors between cells within a tissue?

Enzymatic mutation detection method, This technique utilizes an enzyme reso...

This technique utilizes an enzyme resolvase, endo vii, cloned from the bacteriophage t4. This enzyme has high specificity to find deletions, insertions, and base substitutions muta

What is the determination of vitamin B1, What is the Determination of vitam...

What is the Determination of vitamin B 1 Vitamin B 1 is determined by chemical method and microbiological assay. In the chemical method, vitamin B 1 is oxidized in alkaline

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd