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

Population distribution, Population Distribution - Population Parameters an...

Population Distribution - Population Parameters and Regulation Dispersion or distribution refers to the pattern of distribution of individuals of a population. As shown in Fig

What is speciation, What is speciation? The Speciation is the process b...

What is speciation? The Speciation is the process by which different species emerge from a common ancestor species. The Speciation generally begins when populations of the same

Inter phase - cell cycle, The period of life cycle of cell (cell cycle) bet...

The period of life cycle of cell (cell cycle) between two consecutive divisions is termed as the Interphase or misleading called resting phase. It is a period

Advantages and disadvantages of solar energy, Advantage of solar energy: ...

Advantage of solar energy: 1.         It is renewable: it produce comes from sun, so it is plentiful and will always be there   as long we need it . 2.         Solar

Explain the anabolic phase - dietary management for burns, Explain the Anab...

Explain the Anabolic Phase - Dietary Management for Burns? During this period the patient is well hydrated and the reactions due to metabolic stress are under control. The pati

Explain the types of care of teeths, Explain the types of care of teeths ...

Explain the types of care of teeths a) Plastic/ Nylon  Scalers: These are available in a variety of shapes and are moderately effective in calculus removal. Can be Ultrasonic

Which elements contains carbohydrates, (a) Which elements contains Carbohyd...

(a) Which elements contains Carbohydrates (b) Which elements contains Proteins   a) Carbohydrates contain the elements carbon , hydrogen and oxygen. b) Protei

Explain fats requirements during thyphoid, Explain fats requirements during...

Explain fats requirements during thyphoid Fats: Use of fats should be in moderation. This is because the typhoid patient has a compromised ability to digest and assimilate due

Contagious bovine pleuropneumonia (cbpp), Contagious bovine pleuropneumonia...

Contagious bovine pleuropneumonia (CBPP) This is a highly infectious disease and is of major economic importance in certain tropical countries. The causative organism is Mycop

What is a terrestrial organism, Explain what is a terrestrial organism? ...

Explain what is a terrestrial organism? Ans) 'Terra' is the Latin word for earth. Thus, an animal that lives on the surface of the earth is known as terrestrial. This is the si

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