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Sperm Competition And Sex Allocation In Simultaneous Hermaphrodites, Eric Charnov
Sperm Competition And Sex Allocation In Simultaneous Hermaphrodites, Eric Charnov
Biology Faculty & Staff Publications
Sex allocation theory is developed for hermaphrodites having frequent copulations and long-term sperm storage. Provided the sperm displacement mechanisms are similar to those known in insects, the ESS allocation to sperm versus eggs satisfies a rather simple rule. There are no data to test this rule, as yet.
Sex Ratio Evolution In A Variable Environment, Eric Charnov, Hartogh R.L. Los-Den, W.T. Jones, J. Van Den Assem
Sex Ratio Evolution In A Variable Environment, Eric Charnov, Hartogh R.L. Los-Den, W.T. Jones, J. Van Den Assem
Biology Faculty & Staff Publications
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.
Natural Selection And Sex Change In Pandalid Shrimp: Test Of A Life History Theory, Eric Charnov
Natural Selection And Sex Change In Pandalid Shrimp: Test Of A Life History Theory, Eric Charnov
Biology Faculty & Staff Publications
This article presents a graphical approach to the genetical theory of sex change (similar to one recently applied to the evolution of simultaneous hermaphroditism). The graphs will help clarify a set of predictions to be tested against data from Pandalid shrimp. These shrimp are protandrous hermaphrodites (reproduce first as males). The goal is to use the genetical theory to predict the age of sex change. Since these shrimp show much geographic variation in this age, they provide a good opportunity to test the evolutionary model.
Sex Ratio: Adaptive Response To Population Fluctuation In Pandalid Shrimp, Eric Charnov, Daniel Gotshall, Jack Robinson
Sex Ratio: Adaptive Response To Population Fluctuation In Pandalid Shrimp, Eric Charnov, Daniel Gotshall, Jack Robinson
Biology Faculty & Staff Publications
Pandalus jordani is a protandrus (sequential) hermaphrodite. Populations show large year-to-year variation in age composition. In response to this variation, individuals alter the age at which they change sex. This response is predicted by a genetic model that assumes an individual shrimp maximizes its genetic contribution to the next generation.
When Is Sex Environmentally Determined?, Eric Charnov, James Bull
When Is Sex Environmentally Determined?, Eric Charnov, James Bull
Biology Faculty & Staff Publications
No abstract provided.
Why Be An Hermaphrodite?, Eric Charnov, J. Maynard Smith, James Bull
Why Be An Hermaphrodite?, Eric Charnov, J. Maynard Smith, James Bull
Biology Faculty & Staff Publications
No abstract provided.