In the summer of 1993, twenty-six graduate and postdoctoral stu- dents
and fourteen lecturers converged on Cornell University for a summer
school devoted to structured-population models. This school was one of a
series to address concepts cutting across the traditional boundaries
separating terrestrial, marine, and freshwa- ter ecology. Earlier
schools resulted in the books Patch Dynamics (S. A. Levin, T. M. Powell
& J. H. Steele, eds., Springer-Verlag, Berlin, 1993) and Ecological Time
Series (T. M. Powell & J. H. Steele, eds., Chapman and Hall, New York,
1995); a book on food webs is in preparation. Models of population
structure (differences among individuals due to age, size, developmental
stage, spatial location, or genotype) have an important place in studies
of all three kinds of ecosystem. In choosing the participants and
lecturers for the school, we se- lected for diversity-biologists who
knew some mathematics and mathematicians who knew some biology, field
biologists sobered by encounters with messy data and theoreticians
intoxicated by the elegance of the underlying mathematics, people
concerned with long-term evolutionary problems and people concerned with
the acute crises of conservation biology. For four weeks, these perspec-
tives swirled in discussions that started in the lecture hall and
carried on into the sweltering Ithaca night. Diversity mayor may not
increase stability, but it surely makes things interesting.