Variability in populations, Biology

Variability refers to the differences in heritable traits exhibited by the individuals of a species. One of the major contributions of Darwin to the study of evolution was his book of 1868, 'The Variation of Animals and Plants under Doxnestication'. Danyin pointed out that populations of living organisms are not composed of identical individuals.

It is indeed true that even monozygotic twins may express differences between them. Onecan cite a number of examples to indicate the differences in different traits in a population. Certain traits are continuously varying such as the height or colour, and certain other traits exhibit two or a few distinct, different categories of individuals with no intermediates. For example in human population, there are P'C tasters and non-tasters; individuals with blood groups A or B or AB or 0, individuals with black or brown or blue eyes, individuals suffering from sickle cell anaemia and individuals who are normal, so on and so forth. Sweet peas may have either red flowers or white ones; Drosophila may have normal or vestigial wings, red or white eyes etc. Essentially the major source of variability in organisms is the genetic variability caused by mutations of all kinds and genetic recombination. Also the subtle effects of environment add another dimension to the variability of traits in natural populations. An oft cited example is the differences exhibited in a number of traits of monozygotic quadruplets of a nine-banded armadillo.

Posted Date: 4/6/2013 1:06:24 AM | Location : United States

Related Discussions:- Variability in populations, Assignment Help, Ask Question on Variability in populations, Get Answer, Expert's Help, Variability in populations Discussions

Write discussion on Variability in populations
Your posts are moderated
Related Questions
Q How do cells get energy for their functioning? Cells get energy for their metabolic reactions from the breaking of organic molecules with high energetic content. This energy

Simple sugars are monosaccharides consisting of a single polyhydroxy aldehyde or ketone unit. Their general formula is (CH 2 0) n (n=3 to 7).

FUNCTIONS OF SKELETON - 1.      Support. 2.      To give shape to the body. 3.      Protection of different organs. 4.       Site for muscle attachment. 5.       He

The structure of leaves Borrow a microscope from another school, a doctor, or a hospital. Study the under- side of leaves and locate the breathing pores or stomata with the two

CONJUNCTI V A - Ectodermal in origin. Formed by epidermis. It is thin, transparent covers cornea. Made up of stratified epithelium. It has 2 parts - (i) Ocular conjunct

Polyarthritis  1)  Gonococcal - Therapeutic trial of pencillin may help in diagnosis of gonococcal  infection.  2)  Viral infections such as rubella and hepatitis B may have

What is Implant Failure The total failure of the implant to fulfill its purpose which are functional, esthetic and phonetic because of mechanical or biologic reasons.

Dissolved Gases and Alkalinity Dissolved Gases The marine environment serves as a gigantic reservoir of dissolved oxygen and carbon dioxide, which respectively help reg

Define the Factors Causing Underweight - Etiology? There are a number of factors causing underweight. These are: Poor selection of food Physical activity Mothe

Q. Dietary Fibre requirement during diabetes? Dietary fibre is that part of food which is not digested by the intestines. High fibre meals have shown to give the best glycemic