Effects of Radiation on Populations of Drosophila Melanogaster with Different Genetic Structures III. Interaction with Population Size

Abstract

A number of populations of D. melanogaster, varying in size from approximately 50 individuals to more than 5000, were chronically irradiated with 4000 r X-rays per generation and studied over a period of 40 generations to determine whether and to what extent the accumulation and equilibrium frequency of lethal chromosomes differed from one to the other. The overall fitness of these populations was studied by comparing the productivity of small samples taken from them, which were allowed to lay eggs and have their offspring develop under optimum conditions. The results of these experiments were as follows