| Popis: |
Among mammals, body size and life span tend to vary inversely within species, but the pattern is less clear in invertebrates. Here, we report on survival and weight of male flies from 29 laboratory strains of Drosophila melanogaster. Natural variation in body mass was enhanced by rearing larvae under normal and limited food conditions. Strain, weight, and larval treatment have significant effects on survival, but higher order interactions are also significant, indicating strain specificity. For pooled data the overall relationship between mass and life span is slight, positive, and statistically significant, but mass explains 40% of the variation in survival. For long-lived 'O' lines reared under normal larval conditions, smaller flies live 16% longer than larger flies; the latter are significantly underrepresented in the most advanced age class. We conclude that the body size-life span relationship is highly strain-specific; that inconsistencies in the literature probably reflect real biological variation; and that variation in body size can be a significant source of experimental noise in survival studies. |
Full Text from ScienceDirect