Regression of Survivability Variance on the Cohort Age in Drosophila melanogaster. I. Survivability: Reaction Norm and Its Inheritance

Abstract

A standard analysis of survivability implies counting the share of living individuals in a cohort at a certain moment in time. We analyze in this work the regression of survivability variance on cohort age in several generations of Drosophila melanogaster Canton-S stock. This estimation reflects the reaction norm for survivability. The approach reveals at least three age phases. The first and second can be approximated by an exponential equation and the third by a logistic dose-response curve. Parameters of these equations remain stable for tens of generations and must therefore be highly heritable.