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 is splitin first heart sound, What is Splitin first heart sound ? ...

What is Splitin first heart sound ? In complete RBBB, due to delay of tricuspid closure, the split is wide. In complete LBBB, due to delay of mitral closure the S I is single.

Explain microbiology of water, Q. Explain microbiology of water? Ans. ...

Q. Explain microbiology of water? Ans. Unlike air, natural waters contain their natural flora, as well as, microorganisms from soil and possibly from animals and se

Homeostasis., drawandlabelthemajorendocrineglandsinthehumanbody

drawandlabelthemajorendocrineglandsinthehumanbody

Define precipitation or solubility of proteins, Define Precipitation or Sol...

Define Precipitation or Solubility of Proteins? Most of the functional properties are dependent on the degree to which the proteins are soluble. The solubility behaviour provid

Define methodology for half and full saturation test, Define Methodology fo...

Define Methodology for Half and Full Saturation Test? 1. Take 5 ml each of starch and dextrin solutions, add 5 ml of saturated solution of ammonium sulfate. Shake thoroughly an

Expression of variability, In the previous sub-section we discussed the pos...

In the previous sub-section we discussed the possible ways by which variabiliti can, be generated. We shall now examine one instance that illustrates the consequence of variability

Agro industrial-animal wastes, Animal wastes Large quantities of anima...

Animal wastes Large quantities of animal wastes are available in the country but generally they are low in nutrient content with poor feeding value to the animals. However, po

What is the lymphatic system, What is the lymphatic system? The lymphat...

What is the lymphatic system? The lymphatic system is a network of specialized valved vessels that drain interstitial fluid (lymph). The lymphatic system is also responsible fo

Define beneficial effects of functional foods, Define beneficial effects of...

Define beneficial effects of functional foods? Several beneficial effects of functional foods have been reported, which include effects such as antioxidant, anticarcinogenic, b

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