Is selection ready when opportunity knocks

摘要: The opportunity for selection, I, defined as the variance in relative fitness, has been called an estimate of ‘total amount selection’. However, while a non-zero I is necessary condition it not sufficient one. We investigated relationship between and magnitude standardized linear non-linear selection gradients body size waterstrider Aquarius remigis, measured over three episodes selection. Male exceeded female daily reproductive success, but difference was statistically significant had little impact on net adult I. Linear were only weakly correlated with uncorrelated Partitioning among revealed that fitness largely generated by prereproductive survival. patterns across life stage suggested analysis differed qualitatively quantitatively from those gradient analysis. In particular, former identified pre-reproductive survival key component even though there total length this stage. conclude useful adjunct to analyses, perhaps most life-history evolution where traits themselves are direct estimates fitness.