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

Conventional agro-industrial oilseed cakes, Conventional agro-industrial oi...

Conventional agro-industrial oilseed cakes Groundnut meal: It is readily available protein source byproduct from the extraction of groundnut, which is a popular human food i

Regulation of glycogenesis, Regulation  of Glycogenesis Glycogen syntha...

Regulation  of Glycogenesis Glycogen synthase,  the key enzyme in glycogenesis, is activated by insulin and glucose and inhibited by CAMP.

Transparency - aquatic habitats, Transparency - Aquatic Habitats Trans...

Transparency - Aquatic Habitats Transparency affects the extent of light penetration. It is indirectly related to turbidity. Suspended particulate matters such as clay, silt a

How do beings of the class reptilia classify\, Concerning the maintenance o...

Concerning the maintenance of body temperature how do beings of the class Reptilia classify? Like fishes and amphibians, beings of the class Reptilia are heterothermic animals

Explain ringworm in humans, Ringworm in humans is caused by : 1. Bacteri...

Ringworm in humans is caused by : 1. Bacteria 2. Fungi 3. Nematodes 4. Viruses Fungi

Factors affecting biotic potential - population growth, Factors Affecting B...

Factors Affecting Biotic Potential - Population Growth Biotic potential differs from one species to another e.g., bacterial populations can grow faster than population of oak

Determine the term - test-retest reliabilities, Determine the term - Test-r...

Determine the term - Test-retest reliabilities The test manual reports reliability data. Test-retest reliabilities for the 13 main scales range from .78 to .96. The problem of

What is hemodialysis, What is hemodialysis? Hemodialysis is the artific...

What is hemodialysis? Hemodialysis is the artificial blood filtration made by exact machines in substitution of the kidneys. Hemodialysis may be essential in patients suffering

List four common exercises you will recommend to a patient, List four commo...

List four common exercises you will recommend to a patient. Common exercises are: - brisk walking - cycling - swimming - playing tennis - dancing - rope skip

Protein truncation test, The protein truncation test (ptt) gives an uncommo...

The protein truncation test (ptt) gives an uncommon exception, targeting mutations that create shortened proteins, majorly premature translation termination. Ptt has various attrac

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