Elevated Temperature Diminishes Reciprocal Selection in an Experimental Plant-Pollinator-Herbivore System

Area of Science:

• Ecology
• Evolutionary Biology
• Climate Change Science

Background:

• Coevolution is driven by reciprocal selection, where interacting species influence each other's evolution.
• Environmental factors, such as temperature, can alter the strength and direction of reciprocal selection.
• Understanding temperature's effects is crucial for predicting coevolutionary responses to global warming.

Purpose of the Study:

• To investigate the influence of elevated temperature on reciprocal selection between the plant Brassica rapa and its pollinator/herbivore Pieris rapae.
• To determine if temperature modifies the microevolutionary dynamics of this plant-insect interaction.

Main Methods:

• Experimental manipulation of temperature into ambient and hot conditions.
• Measurement of plant and butterfly phenotypes, interaction frequencies, and fitness components.
• Calculation of reciprocal selection gradients based on fitness data.

Main Results:

• Reciprocal selection was detected on multiple traits in the ambient temperature environment.
• No significant reciprocal selection was observed between Brassica rapa and Pieris rapae in the hot environment.
• Elevated temperatures demonstrably weakened the reciprocal selection observed under ambient conditions.

Conclusions:

• Experimental evidence indicates that increased temperatures reduce reciprocal selection.
• This weakening effect has significant implications for predicting the ecological and evolutionary consequences of global warming on interacting species.
• Coevolutionary processes may be altered or diminished under future climate scenarios.