Recurring themes. Nature and causes of variation / Susan J. Mazer, John Damuth -- Evolutionary significance of variation / Susan J. Mazer, John Damuth -- Natural selection / Daphne J. Fairbairn, Jeff P. Reeve -- Adaptation / David Reznick, Joseph Travis -- Phenotypic plasticity / Massimo Pigliucci -- Population structure / Leonard Nunney -- Inbreeding and outbreeding / Nickolas M. Waser, Charles F. Williams. Life histories. Age and size at maturity / Derek A. Roff -- Offpsring size and number / Frank J. Messina, Charles W. Fox -- Senescence / Marc Tatar -- Life cycles / Jan A. Pechenik -- Sex and gender / Turk Rhen, David Crews -- Sex ratios and sex allocation / Steven Hecht Orzack -- Ecological specialization and generalization / Douglas J. Futuyma. Behavior. Mating systems / Ann K. Sakai, David F. Westneat -- Sexual selection / Udo M. Savalli -- Cooperation and altruism / David Sloan Wilson -- Foraging behavior / Donald L. Kramer -- The evolutionary ecology of movement / Hugh Dingle, Marcel Holyoak. Interspecific interactions. Ecological character displacement / Dolph Schulter -- Predator-prey interactions / Peter A. Abrams -- Parasite-host interactions / Curtis M. Lively -- Plant-herbivore interactions / May Berenbaum -- Mutualisms / Judith L. Bronstein -- The geographic dynamics of coevolution / John N. Thompson. Adaptation to anthropgenic change. Pesticide resistance / John A. McKenzie -- Predicting the outcome of biological control / Judith H. Myers -- Evolutionary conservation biology / Philip W. Hedrick.