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

Nucleic acid hybridization, Nucleic acid thermodynamics is the learning of ...

Nucleic acid thermodynamics is the learning of how temperature affects the nucleic acid structure of dsDNA (double-stranded DNA). The melting temperature (Tm) is explained as the t

Explain the digestion of carbohydrates, Explain the Digestion of carbohydra...

Explain the Digestion of carbohydrates? You are aware that 60-70% of energy is supplied by the dietary carbohydrates which are primarily present as polysaccharides (starch) fol

How sugar is used in custards, How Sugar is used in Custards? While flo...

How Sugar is used in Custards? While flour protein forms the structure of baked goods, custards are composed of egg protein structures. If the egg white solidifies too early al

Explain boiling point - properties of solution, Boiling Point There are...

Boiling Point There are certain properties of solutions  which are directly connected with vapour pressure and one of it is boiling point.  You must have observed that water bo

Relate the oxide layer and biocompatibility of titanium, Relate the oxide l...

Relate the oxide layer and biocompatibility of titanium. The compatibility of a metal with its host environment depends on its resistance to biodegradation and on the degree of

Explain cell cycle , The life of a eukaryotic cell can be explained ...

The life of a eukaryotic cell can be explained as a cell cycle. Mitosis and cell division happens in the M phase that lasts for only about 1 h. This is followed by the G1 phase whe

State in detail about dark adaptation, State in detail about Dark Adaptatio...

State in detail about Dark Adaptation Dark adaptation is a phenomenon by which retina and pupil react to decreased illumination. Test is performed using Goldmann-Weeke's adapto

Explain the bioavailability of vitamin d, Explain the Bioavailability of Vi...

Explain the Bioavailability of Vitamin D? The nutritional availability of vitamin D is less significant because it can be endogenously produced and retained for long periods by

Bud dormancy - plant growth substances, Bud Dormancy - Plant Growth Substan...

Bud Dormancy - Plant Growth Substances Environmental Factors The most important factor inducing dormancy appears to be photoperiod. Short days induce dormancy in many w

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