Variability in populations, Biology

Assignment Help:

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.


Related Discussions:- Variability in populations

Practical preparation - qualitative test for monosaccharides, Define Practi...

Define Practical Preparation - Qualitative Test for Monosaccharides? 1. Wear your labcoat. Make sure your hair is tied and you have no loose clothing. These can be dangerous in

Relaxin - reproduction, Normal 0 false false false EN-I...

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

Population growth - population parameters, Population Growth - Population P...

Population Growth - Population Parameters and Regulation The size of a population depends upon the balance between natality and immigration through which individuals are added

Define minerals, Define minerals Definition of minerals, as it applies ...

Define minerals Definition of minerals, as it applies to food and nutrition usually refers to  the elements other than carbon, hydrogen, oxygen and nitrogen that are present in

Cytoplasm, CYTOPLASM Name proposed by Strassburger. According to Muhlet...

CYTOPLASM Name proposed by Strassburger. According to Muhlethaler and Frey- Wyssling fluid outside nucleus is called cytoplasm. Two parts of cytoplasm. (1) Hyaloplasm or

Describe the external features of the heart, Question 1 Describe the exter...

Question 1 Describe the external features of the heart. Add a note on circulation of blood within the heart Question 2 Discuss the major joints of thorax and pelvis Quest

Limiting factor - ecosystem, Limiting Factor - Ecosystem In all ecosys...

Limiting Factor - Ecosystem In all ecosystems one factor, usually abiotic, limits the growth of organisms and is therefore called a limiting factor. The limiting factor is one

Which respiratory adaptations or organs do, Q. Which respiratory adaptation...

Q. Which respiratory adaptations or organs do aquatic and terrestrial arthropods respectively present? In crustaceans, typical aquatic beings, there are richly vascularized gil

Define comprehensive dietary management regime of patient, Define Comprehen...

Define Comprehensive Dietary Management Regime of Patient? A comprehensive dietary management regime of the patient should be based on the patient profile as gathered pre and p

Determine general principles of allergy management, Determine General Princ...

Determine General Principles of Allergy Management? The four general principles of allergy management include: 1.  Avoid factors that cause symptoms. 2.  Use appropriate

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