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

Cell cycle, Provide a link to the graph, describe the variables, and interp...

Provide a link to the graph, describe the variables, and interpret the meaning of the graph

Why iodine is important for human body, Why Iodine is Important for Human B...

Why Iodine is Important for Human Body? Iodine is an essential constituent of the thyroid hormones: thyroxine (T 4 ) and triiodothyronine (T 3 ), which have a key role in growt

Complications during angina pectoris, Q. Complications during angina pector...

Q. Complications during angina pectoris? It is a symptom giving a warning of impending myocardial infarction, sudden cardiac death or even ischemic necrosis of the brain leadin

Features of amphibian gastrulation, Features of Amphibian Gastrulation ...

Features of Amphibian Gastrulation Major features of amphibian gastrulation are: Ectoderm surrounds the embryo by Epiboly. Gastrulation is initiated by a limited i

Cell wall, CELL WALL Discovered by Robert Hooke , 1665 when he saw ...

CELL WALL Discovered by Robert Hooke , 1665 when he saw dead empty cork cells. Bonne r - studied the chemical nature of cell wall. The cell wall is a rigid & prote

Explain the peptones - complex media, Explain the Peptones - Complex Media?...

Explain the Peptones - Complex Media? Peptones are protein hydrolysates obtained by partial digestion of meat, casein, soya meal, gelatin or other protein source. These provide

Left border of the heart, Connect point A and D by line which is convex to ...

Connect point A and D by line which is convex to the left. The left border is formed by the left ventricle except at its upper end which is formed by the left auricle where there i

Why protein requirements of athletes get increased, Why Protein requirement...

Why Protein requirements of athletes get increased? Protein requirements of athletes, particularly those engaged in strength and power events, may be increased above those of s

Hydra – metazoa, Hydra – Metazoa The animals of phyla Cnidaria and Cte...

Hydra – Metazoa The animals of phyla Cnidaria and Ctenophora are made up of only two germ layers: ectoderm which forms the outer covering of the animal and endoderm which is t

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