In this report, we develop a general theory of the relationship between life history and population structure for largemouth bass. In its most usable form the model is represented by a stochastic integral equation that is analogous to the classical Lotka model for age structure of populations. The corresponding differential equations can also be used successfully when closed-form solutions are available or when the phenotype dimension is low enough to permit numerical solution. Three general conclusions are presented. First, population dynamics may be appropriately viewed as a consequence of life history phenomena. This view suggests that, at least where prediction of population structure or where explanation of the phenomena is desired, such phenomena as density-dependence may be most appropriately described by analyzing effects of population structure and density on life history in the population. The second conclusion is that variation in life history may be important in determining population structure. Terms describing effects of variation are explicitly included in the model equations. The magnitude of these terms, however, is completely unknown for any life histories with which we are familiar. The third conclusion to be drawn is that population structure, at least averaged over time, should be fairly stable in large populations. Effects of variation in small populations, on the other hand, have not been analyzed and might be important.

Bass Research Foundation