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

Briefly explain lichens organism, Briefly explain Lichens organism? Lic...

Briefly explain Lichens organism? Lichens are unique organisms consisting of a symbiotic relationship between a fungus and a photosynthetic organism. They represent a type of s

Define source of electrons - growth of microorganism, Define Source of Elec...

Define Source of Electrons - Growth of Microorganism? Depending upon the source of electrons used by microorganisms, these are known as - a) Lithotrophs (rock eaters) - use

Sympathetic and para sympathetic nervous system, SYM P A THETI C NERVOU...

SYM P A THETI C NERVOUS SYSTEM These sympathetic chain are connected with ramus comminicause of thoracic & lumber part. Due to this reason this system is called as t

What is the concept of lophophore, What is the concept of Lophophore? A...

What is the concept of Lophophore? A unique double ring of hollow ciliated tentacles that surround the oral opening in some animal phyla. There is some debate as to whether the

What is cardiac catheterization, Q. What is Cardiac Catheterization? Ro...

Q. What is Cardiac Catheterization? Routine cardiac catheterization is not necessary in patients with mitral regurgitation. It may be done when there is discrepancy between cli

Photosynthesis, test to prove that carbondioxide is needed for photosynthes...

test to prove that carbondioxide is needed for photosynthesis to take place

Determine the enzymatic chemical reactions, How does facilitated diffusion ...

How does facilitated diffusion present similarities with enzymatic chemical reactions? One of the main examples of facilitated transport is the entrance of glucose from the blo

How is hiv transmitted, Q. How is HIV transmitted? What is the disease caus...

Q. How is HIV transmitted? What is the disease caused by this virus? The HIV (human immunodeficiency virus) is supposed to be transmitted through blood, semen, vaginal secretio

Biochemistry, Water is most dense and thus heavier at 4 degreese celceus. A...

Water is most dense and thus heavier at 4 degreese celceus. At 0 degreese celceus ice forms and can float on liquid water. Assuming that ice were most dense at 0 degreese celceus,

Direction of flow, Direction of flow--either towards or away from the trans...

Direction of flow--either towards or away from the transducer (positive or negative Doppler shifts). Timing-instantaneous velocity and direction of flow throughout the various

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