An Experimental Test of Models Predicting Life-History Characteristics

Abstract

The predictions of bet-hedging (Stearns 1976) and r- and K-selection theories of life-history strategies are tested. This is done by providing 4 different selection regimes through all possible combinations of larval and adult mortality in Drosophila melanogaster. Effects of these regimes were measured on various life-history parameters. Although no model examined predicted outcomes of experiments very accurately, the general prediction of bet-hedging models seems to be borne out. High mortality of adults apparently selects for r-characteristics, high mortality of larvae selects for K-characteristics. The simple model of r- and K-selection based on the effects of density alone seems inadequate to explain variation in life-history features of complex organisms.