Genetic variation in a population

Essential to the definition of Pharmacogenetics is the term genetic polymorphism. It is extrapolated that there are at least three million genetic polymorphisms in the human genome. Historically, a genetic polymorphism was defined as a genetic variation with a population frequency of 1% and above, but the larger inter-ethnic variation of population frequencies makes a strict definition based on such frequencies impractical. The most common molecular type of polymorphism is the... 

Vermeire S, Wild G, Kocher K, Cousineau J, Dufresne L, Bitton A, Langelier D, Pare P, Lapointe G, Cohen A, Daly MJ, Rioux JD. CARD 15 genetic variation in a Quebec population prevalence, genotype-phenotype relationship, and haplo-type structure. Am J Hum Genet 2002 71 74—83. 

McDonald, K.S. Cocks, P.S. and M.A. Ewing (2005) Genetic variation in five populations of strawberry clover (Trifolium fragiferum cv. Palestine) in Western Australia.- Australian Journal of Experimental Agriculture 45, 1445-1451. 

Even more subtle differences in populations may occur. The genetic variation within a population can be rather substantial. The two dimensional ZNGIs can be expanded to demonstrate the fact that the ability of organisms to consume and use resources is not a point but a continuum dictated by the genetic variation of the population. Figure 11.11 illustrates this idea. 

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