We develop a natural selection model for sex ratio control in a spatially variable environment. Predictions of sex ratio alteration as a function of environmental change are tested in laboratory experiments with two parasitic wasps. Field data from a variety of other organisms also support the model. Finally, we discuss possibilities and difficulties for testing this type of evolutionary model.
hermaphrodites, sex ratio, environmental variability, parasitic wasps
Charnov, E.L., R.L. Los—den Hartogh, W.T. Jones and J. van den Assem. 1981. Sex ratio evolution in a variable environment. Nature 289:27-33