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
Describe forces that contribute to cell''s electrochemical gradient. How does electrochemical gradient influence ion transport?

Q. What are biogeochemical cycles? The Biogeochemical cycles are representations of the circulation and recycling of matter in nature. The major biogeochemical cycles studie

What is the best microscope to get a detailed view of the parts inside of a preserved plant cell

URETERS From hilum of each kidney emerges out a tube. Wall is thick. Lumen is star shaped. 28 cm. long. Transitional epithelium present in wall. Open in to urinary bla

Explain about the Drying - methods of food processing? Drying is the oldest and probably the simplest way of preserving food. It is usually accomplished by the removal of water

Define Prevention of IDD - Iodized salt distribution? Many approaches to reduce iodine deficiency has been formulated. Some of these are reviewed herewith: Iodized salt dist

Q. Why are euglenas involved in polemics related to their taxonomic classification? Euglenas are involved in taxonomic polemics because they tend to be classified sometimes as

Access burs through the crown:    Carbide fissure burs : cut through metal ( amalgam alloy or cast metal ) or composite resin.    Porcelain fused to metal : -A round diam

OESTROU S CYCLE - Also known as heat period. Common in rabbit, cat, dog, sheeps. In this period desire for copulation occur. Possibility of fertilization is 100%.

Q. Symptoms of aortic regurgitation? Patients with chronic severe AR may be asymptomatic for many years and it may be picked up on routine examination. Some patients may remain