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

What do you mean by overgloves, Q. What do you mean by Overgloves? The ...

Q. What do you mean by Overgloves? The purpose of these gloves is to use time more efficiently and to protect the skin on the hands through minimizing the number of times that

Menstrual cycle- reproduction, Menstrual Cycle- Reproduction Menstrual...

Menstrual Cycle- Reproduction Menstrual cycles are characteristic of primates and do not occur in other vertebrate groups. The length of the cycle is highly variable, though 2

Explain vaccine of typhoid, Typhoid  Typhoid vaccine is recommended for...

Typhoid  Typhoid vaccine is recommended for travellers to developing countries in Central and South America, Africa and Asia, especially if they plan a long stay or may be livi

What is severity and extent of lesion in cad, What is Severity and Extent o...

What is Severity and Extent of Lesion in coronaw artery disease? Apart from the high prevalence, the other disturbing features of CAD in South Asians are the severity and exten

Explain the dietary management in trauma, Explain the Dietary Management in...

Explain the Dietary Management in Trauma? Trauma As a result of metabolic responses to injury, there is an increase in the energy expenditure. Oxidation of body fat stores take

Explain about ridge mapping, Explain about Ridge mapping Ridge relation...

Explain about Ridge mapping Ridge relationship is also critical especially in cases with multiple implants and fixed prosthesis, which is an advanced treatment procedure. But,

What is the permeability to sodium ions, An impermeable membrane separates ...

An impermeable membrane separates a one liter solution of 1M NaCl in the left compartment from a one liter solution of 2M KCl in the right compartment.  At 2 AM the membrane became

Can you explain para-sternal view, Q. Can you explain Para-sternal View? ...

Q. Can you explain Para-sternal View? Various congenital anamolies can be detected in this view are perimembranous VSD (transducer anbled towards right hip), doubly commit

Theory of natural selection or darwinism, THEORY OF NATURAL SELECTION OR DA...

THEORY OF NATURAL SELECTION OR DARWINISM Theory of CharIes Darwin (1809 - 1882) about evolution marks the beginning of an era in understanding of evolution. At the age

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