Genetic variation fitness

Genetic variation in discrimination and transpiration efficiency In the experiments decribed earlier on A and W in wheat, peanut, barley, tomato and cotton, there was a great deal of genetic variation which still fitted the relationship described by Equation 8. The range of A in one species is often about 2 to 4 x 10 (e.g. Hubick et al., 1986 with peanut, and similarly from surveys of wheat, cotton, barley and cowpea). 

Fowler K, Semple C, Barton NH, Partridge L 1997 Genetic variation for total fitness in Drosophila melanogaster. Proc R Soc Lond Ser B Biol Sci 264 191—199 Hairston NG Jr, Dillon TA 1990 Fluctuating selection and response in a population of freshwater copepods. Evolution 44 1796-1805 Herrnstein RJ, Murray C 1994 The bell curve. Free Press, New York... 

Wilson (1994) has argued that it is premature to dismiss the possibility of adaptive genetic variation. Both simulations (e.g. Wilson Turelli 1986) and empirical data (Wilson 1998) suggest that complex polymorphisms (involving at least two loci) can be maintained in a population if their fitnesses are sufficiently high, even if intermediate forms have relatively low fitness. In one model (Wilson... 

Prediction 4. Most of our uniquely human mental abilities should show particularly high -loadings and /loadings, compared to more ancient mental capacities common to other great apes, primates or mammals. Like other sexually selected fitness indicators, they should also show higher coefficients of genetic variation and phenotypic variation, and at least moderate heritabilities. 

Simopoulos, A.P. and Pavlou, K.N., Eds., Nutrition and Fitness 1 Diet, Genes, Physical Activity and Health, vol. 89, World Rev. Nutr. Diet., Karger, Basel, 2001. Simopoulos, A.P., Genetic variation and dietary response nutrigenetics/nutrigenom-... 

Evolution by natural selection takes place through the success and failure of individuals to survive and reproduce. It thus involves the lowest level of taxonomic structure - the individual. To understand many of the processes of evolution at higher taxonomic levels, it is necessary to study and understand the behaviour of populations and individuals in nature and the laboratory to record their survival and measure their fitness. This study of the interaction between individual fitness and genetic variation lies within the field of population genetics. 

Mutations that alter phenotypes are generally harmful, but a very small proportion may increase an organism s fitness these spread through the population over successive generations by natural selection. Mutation is therefore essential for evolution, being the ultimate source of genetic variation. 

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