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

What is hipot test ?, Hipot is an abbreviation for high potential. Usually,...

Hipot is an abbreviation for high potential. Usually, Hipot is a term given to a class of electrical safety testing instruments used to confirm electrical insulation in finished ap

Name diseases caused by viruses, Name three diseases caused by viruses. ...

Name three diseases caused by viruses. There are many diseases caused by virus. Virus diseases include colds, influenza, herpes, mumps, measles, chicken pox, rubella, hepati

Importance of primary prevention of diabetes mellitus, Q. Importance of Pri...

Q. Importance of Primary prevention of diabetes mellitus ? Primary prevention has been found to be cost effective in the long run as it reduces unwarranted human suffering. Pre

What are dendritic cells, Dendritic Cells a. Are the same as macrophages b....

Dendritic Cells a. Are the same as macrophages b. Bind and digest pathogen proteins c. Secrete immunoglobulin d. All of the above

Mycoplasmosi, MYCOPLASMOSIS Mycoplasma organisms are the smallest free li...

MYCOPLASMOSIS Mycoplasma organisms are the smallest free living, lack of cell-wall and bounded by a triple layer of plasma membrane. The organisms are pleuomorphic in shape, viz.

Clostridium perfringens infections, Clostridium perfringens infections ...

Clostridium perfringens infections Cl. perfringens is a rod-shaped, spore-bearing anaerobic organism. It is capsulated and non-motile. A characteristic feature of the organism

What is lasting form in gametophyte-pteridophytes-sporophyte, What is the l...

What is the lasting form in the gametophyte, pteridophytes or the sporophyte? How can it be compared to bryophytes? The lasting form in pteridophytes is the diploid (2n) sporop

Illustrate the structure of the central nervous system, Q. What is the stru...

Q. What is the structure of the central nervous system that regulates pulmonary respiration? The reaction is catalyzed by the enzyme carbonic anhydrase present in red blood cel

Do fishes there an open or closed circulatory system, Do fishes there an op...

Do fishes there an open or closed circulatory system? How many chambers does a fish heart have? How does blood flow all through the fish body? As in every vertebrate the circul

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