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

Interrupted suture technique-prosthetic aortic valve, Interrupted suture te...

Interrupted suture technique: Synthetic braided 2 '0' sutures (ethibond) with 17mtn needles on either end and a pledget is used. Alternate green and white sutures are taken aft

Assessment of exstrophy of the bladder, Assessment You can observe it...

Assessment You can observe it visually at birth. The anterior abdominal wall is absent and the posterior bladder lining which is bright red in colour is exposed. Urine seeps

Corelation of st depressoin with coronary angiography, Q. Corelation of ST ...

Q. Corelation of ST Depressoin with Coronary Angiography? Various investigators considered 1 mm of horizontal or downsloping ST depression to denote a positive test and used fr

Define reaction of fehling solution with lactose, Define Reaction of Fehlin...

Define Reaction of Fehling solution with lactose? After complete reduction of cupric ions, the indicator is reduced by lactose to a leuco compound, restoring the red colour of

Explain about the oncogenic viruses, Explain about the Oncogenic Viruses? ...

Explain about the Oncogenic Viruses? Certain viruses that interfere with the functions of the regulatory genes have been identified. These viruses are called oncogenic viruses.

Illustrate about the insulin and insulin syring, Insulin, insulin syringe ...

Insulin, insulin syringe and insulin devices Insulin is the hormone used to treat diabetes mellitus. Insulin is given in the form of injection, because the gastro intestinal tr

What are functions of the epithelium, Q. What are some functions of the epi...

Q. What are some functions of the epithelium? The epithelial tissues can perform protection, covering and impermeability against the environment, for instance, in the skin, res

Explain adverse effects of adefovir dipivoxil, Adverse Effects of Adefovir ...

Adverse Effects of Adefovir dipivoxil  Doses of adefovir used for HBV are generally well tolerated but may be associated with asthenia, headache, diarrhea and abdominal pain. H

Aldoses and ketoses, A carbohydrate   is composed   of carbon (carbo-), and...

A carbohydrate   is composed   of carbon (carbo-), and hydrogen   and oxygen (-hydrate).  The  easiest  carbohydrates  are  the  monosaccharides that  have  the common  formula  (C

Do octopus and squids have exoskeleton, Do octopus and squids have exoskele...

Do octopus and squids have exoskeleton? Octopus and squids normally do not produce external shell (some squid species can have an internal shell). One cephalopod group, the nau

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