amy is favored and sexual selection also tends to be relatively weak (Fig. 10.5). Thus, the most productive place to begin investigation of how the spatial and temporal distributions of fertilizations are similar in plants and animals may be with these polygamous species. Few data are now available that could test the generality of this hypothesis. However, sufficient anecdotal information exists to justify efforts by researchers to close the conceptual and empirical gap between studies of plant and animal mating systems. As if to invite collaborative research, the population genetic tools, both theoretical and empirical, that characterize research in plant mating systems are less well developed for animals, while the spatiotemporal data and quantitative genetic methods for measuring selection that characterize research in animal mating systems are less well developed for plants. Each discipline has much to offer the other and much exciting work remains to be done.

I thank Michael J. Wade for his fundamental role in developing the ideas presented in this manuscript, John Avise and Francisco Ayala for organizing In the Light of Evolution III, and 2 anonymous reviewers for their comments on an earlier draft of this manuscript. This work was supported by National Science Foundation Grants NSF FIBR-0425908 and DBI-0552644.