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
Explain Non-surgical Endodontic Retreatment - Missed Canal Missed root canal as it hold pulp tissues and bacteria is major cause of endodontic failure. Mandibular molar

Explain the Superficial Minor Burns? Superficial minor bums are immersed immediately in cool water if possible. The burn is carefully cleaned to prevent infection. If dirt is d

How do the plants classify according to their photoperiodism-based flowering? According to their photoperiodism-based the flowering plants classify as long-day plants, those th

Age Distribution - Population Parameters and Regulation It is obvious that individuals in a population will be of different age groups. Relative numbers of young and old indiv

An adequate level of pressure is needed in the arteries to keep the blood flowing through the cardiovascular system. The chief determinant of arterial pressure is the volume of blo

What are possible treatments available for a herniated disc injury?

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Question 1: Describe the term Intellectual Property Rights. Show the difference between Patents, industrial designs, and trademarks. Define the term Intellectual Property

Give the salient features of phylum protozoa

Define some adverse effects of saponins? The adverse effects of saponins may be described as under: - A well-known toxic effect is 'erythrocyte lysis' since they interact wi