The occurrence of differences between individuals. Such differences may be due to inherited (genetic) and environmental factors. Genetic variation is commonly due to recombination in sexually reproducing organisms, although the ultimate source of all genetic variation is mutation (see gene). Environmental variation may be caused by various factors, such as population density, nutritional status, light intensity, etc. A characteristic that is largely influenced by environmental factors is said to show phenotypic * plasticity and exhibit low * heritability. Variation may be due to differences in kind (see qualitative variation ) or differences in degree (see quantitative variation ). |
