Experimental Evidence for an Eco-Evolutionary Coupling between Local Adaptation and Intraspecific Competition

Area of Science:

• Ecology and Evolutionary Biology
• Population Dynamics
• Eco-Evolutionary Dynamics

Background:

• Intraspecific competition is a key ecological process causing negative density dependence in population demographics.
• Local adaptation, an evolutionary process, can also influence population growth rates and interact with ecological factors.
• Understanding the interplay between ecological and evolutionary processes is crucial for a comprehensive view of population regulation.

Purpose of the Study:

• To investigate how adaptive evolution and ecological processes, specifically intraspecific competition, are coupled.
• To determine if local adaptation influences the strength of density dependence in populations.
• To explore the reciprocal effects between ecological competition and evolutionary adaptation on population growth.

Main Methods:

• Experimental study using damselflies (predaceous aquatic insects).
• Assessed the impact of density-dependent intraspecific competition on per capita growth rates.
• Evaluated the role of local adaptation in modulating demographic rates and competition.

Main Results:

• Both density-dependent intraspecific competition and local adaptation were found to reduce per capita growth rates.
• In some instances, local adaptation's effect on reducing growth rates surpassed the impact of increased density.
• A significant coupling was observed between ecological and evolutionary properties, suggesting reciprocal influences.

Conclusions:

• Eco-evolutionary dynamics play a critical role in regulating key demographic processes within populations.
• The strength of density-dependent competition may depend on the extent of local adaptation, or vice versa.
• These findings highlight the interconnectedness of ecological competition and local adaptation in shaping population dynamics.