| Popis: |
Phenotypic variation is ubiquitous in natural populations, both within and between populations of the same species. Variation in body size is an obvious example of phenotypic variation and in some insects can reach extreme limits, intrapopulational differences in weight being as great as six-fold in the coleop-teran Asemum striatum (Andersen and Nilssen 1983), and five-fold in female Aedes sierrensis (Hawley 1985). Variation in phenotype within a population has caused considerable taxonomic confusion. In many insect species, for example, populations may comprise two distinct morphs, winged and wingless, the two morphs also frequently showing other substantial morphological differences. Such variation has led many taxonomists to classify these morphs as separate species. |
