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Full-Text Articles in Other Ecology and Evolutionary Biology

Compensation For Herbivory In Wild Sunflower: Response To Simulated Damage By The Head-Clipping Weevil, Diana Pilson, Karin L. Decker Jan 2002

Compensation For Herbivory In Wild Sunflower: Response To Simulated Damage By The Head-Clipping Weevil, Diana Pilson, Karin L. Decker

Diana Pilson Publications

Herbivore damage is generally detrimental to plant fitness, and the evolutionary response of plant populations to damage can involve either increased resistance or increased tolerance. While characters that contribute to resistance, such as secondary chemicals and trichomes, are relatively well understood, characters that contribute to a plant’s ability to tolerate damage have received much less attention. Using Helianthus annuus (wild sunflower) and simulated damage of Haplorhynchites aeneus (head-clipping weevil) as a model system, we examined morphological characters and developmental processes that contribute to compensatory ability. We performed a factorial experiment that included three levels of damage (none, the first two, …


Discounting And Reciprocity In An Iterated Prisoner’S Dilemma, David W. Stephens, Colleen M. Mclinn, Jeffrey R. Stevens Jan 2002

Discounting And Reciprocity In An Iterated Prisoner’S Dilemma, David W. Stephens, Colleen M. Mclinn, Jeffrey R. Stevens

Jeffrey Stevens Publications

The Iterated Prisoner’s Dilemma (IPD) is a central paradigm in the study of animal cooperation. According to the IPD framework, repeated play (repetition) and reciprocity combine to maintain a cooperative equilibrium. However, experimental studies with animals suggest that cooperative behavior in IPDs is unstable, and some have suggested that strong preferences for immediate benefits (that is, temporal discounting) might explain the fragility of cooperative equilibria. We studied the effects of discounting and strategic reciprocity on cooperation in captive blue jays. Our results demonstrate an interaction between discounting and reciprocity. Blue jays show high stable levels of cooperation in treatments with …