Expression of variability, Biology

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.

Posted Date: 4/6/2013 1:09:54 AM | Location : United States







Related Discussions:- Expression of variability, Assignment Help, Ask Question on Expression of variability, Get Answer, Expert's Help, Expression of variability Discussions

Write discussion on Expression of variability
Your posts are moderated
Related Questions
Q. How many ATP molecules are produced for every glucose molecule used in fermentation? And How many ATP molecules are produced for each glucose molecule used in aerobic respiratio

What are the cells responsible for the production of antibodies? The cells that make antibodies, i.e., the cells of the humoral immune system, are the B lymphocytes (B cells).

Diversity is defined as the no of species present in a community termed as "species richness". We can represent species biodiversity at different geographical scales as alpha, beta

HYPOTHALAMUS - Hypothalamus develops from the ectoderm of the embryo. Location and Structure. It lies below or inferior to the thalamus. The hypothalamus is connected to t

Explain the Transmission Electron Microscope Here, thin and dehydrated specimen is used. Electrons pass through the specimen and form image on to photographic film. These are u

Identical Twins Human twins may be similar, when they are formed from one egg (monozygotic) or fraternal while they are the result of fertilization of two different ova releas

STRUCTURE Mitochondria is a double unit membranous structure. It consists of outer & inner membranes. Outer membrane is smooth & made up of lipoproteins. It bears m

Q. What are the major cellular features of fungi? There are pluricellular and unicellular fungi. All fungi are heterotrophs and eukaryotes. Fungi have cells with cell wall m

During our discussion of replication origins we took a step-by-step look at the method of cloning DNA fragments into plasmids . Based on your knowledge of this discussion which

Bone Cells Bone cells may be divided into two broad classifications depending on whether they make bone or resorb it. Osteoblasts make bone, while Osteoclasts resorb or take aw