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

Explain cytological approach in taxonomy, Explain Cytological Approach in T...

Explain Cytological Approach in Taxonomy Cytotaxonomy deals with all the aspects of taxonomy at a cellular level. This includes, the structural, genetic and biochemical aspect

Changes in animal life during xerosere, Changes in Animal Life during Xeros...

Changes in Animal Life during Xerosere Just like the hydrosere, there occur successive changes in animal life during the xerosere. A few mites are usually found associated wi

Polyphyletic theory, Please I need short notes on polyphylrtic theory

Please I need short notes on polyphylrtic theory

Bacterial diseases-sheep and goats, Sheep and goats The disease is rea...

Sheep and goats The disease is readily transmissible to human being from goats, and is known as Malta fever, Mediterranean fever or undulant fever. The chief causal agent is B

Does natural selection produce an effect directly on genes, Does natural se...

Does natural selection produce an effect directly on genes, on genotypes, or on phenotypes? Explain please.

What is the endocrine function of the placenta, What is the endocrine funct...

What is the endocrine function of the placenta? The placenta besides being the organ by which the exchange of substances among the mother and the fetus is done also has the fun

Theories of origin of life, what we the strengths and weaknesses of pangene...

what we the strengths and weaknesses of pangenesis theory

Person''s red blood cell content of 2, How would carbon monoxide poisoning ...

How would carbon monoxide poisoning affect a person's coloring, particularly of the mucous membranes? How would it affect the hemoglobin concentration, hematocrit, and percent oxyh

Define the factors that affect the rate of drying, Define the Factors that ...

Define the Factors that Affect the Rate of Drying? Factors that affect the rate of drying are as follow: 1) The fat content of the food-Higher fat contents generally result

Poultry and duck diseases-avian leucosis complex (alc), Avian leucosis comp...

Avian leucosis complex (ALC) The disease in poultry is caused by an RNA virus classified under avian type C Retrovirus group under the family Retroviridae. Epidemiology:

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