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

Define comprehensive dietary management regime of patient, Define Comprehen...

Define Comprehensive Dietary Management Regime of Patient? A comprehensive dietary management regime of the patient should be based on the patient profile as gathered pre and p

Enzyme-controlled reaction, If an enzyme-controlled reaction normally takes...

If an enzyme-controlled reaction normally takes place at 10ºC, in general terms how will the reaction be affected by  (a) a fall in temperature to 2°C , (b) a rise in temperature t

Which are the brain regions associated with memory, Which are the brain reg...

Which are the brain regions associated with memory? According to researchers some of the main regions of the nervous system associated with the memory phenomenon are the hippoc

Genetic drift, It is generally believed that genetic drift occurs as a resu...

It is generally believed that genetic drift occurs as a result of sampling error. As we said earlier it occurs in small populations such as peripheral isolates. We may demonstrate

Determine some common micronutrient deficiencies, Determine some Common Mic...

Determine some Common Micronutrient Deficiencies? Vitamin A deficiency Iron deficiency anaemia Iodine deficiency disorders Zinc deficiency

Determine the term - vascular disorders, Determine the term - Vascular diso...

Determine the term - Vascular disorders Normal central nervous system functioning can be affected by a number of vascular problems, because blood-vessel disease or damage can g

Explain dna or rna segment, DNA or RNA segment tagged with a radioactive mo...

DNA or RNA segment tagged with a radioactive molecule is called: 1. Vector 2. Probe 3. Clone 4. Plasmid Probe

Handling animals in lab, Handling : The desire for survival is same whethe...

Handling : The desire for survival is same whether in animals or human beings. You may be aware of the ability of even tiny animals to scratch and bite. So we won't say any more o

Fundamental polymers of life, The synthesis of the three fundamental polyme...

The synthesis of the three fundamental polymers of life, DNA, RNA and protein, is template-directed. This means that - Answer A. the monomers are assembled one by one in a sequence

How many kcal of gross energy were formed, The question asks . . . 18 moles...

The question asks . . . 18 moles of moles of maltose are completely oxidized by the reactions of the final oxidative pathways (Embden-Myerhoff Pathway and Krebs Cycle). How many AT

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