Eco-Evolutionary Interactions With Multiple Evolving Species Reveal Both Antagonistic and Additive Effects

Area of Science:

• Eco-evolutionary dynamics
• Community ecology
• Evolutionary biology

Background:

• Most eco-evolutionary research examines single-species evolution.
• Little is known about simultaneous multi-species evolution and its ecological consequences.

Purpose of the Study:

• To quantify evolution-mediated ecological effects in zooplankton communities with simultaneous multi-species evolution.
• To compare eco-evolutionary dynamics under different selection backgrounds.

Main Methods:

• Experimental evolution of four zooplankton species (three Daphnia, one Scapholeberis) under heatwave selection.
• Manipulation of which species within the community evolved.
• Quantification of direct and indirect eco-evolutionary effects on species abundances, community composition, and grazing pressure.

Main Results:

• Observed transient eco-evolutionary effects that varied depending on which species evolved.
• Evolution did not consistently increase the abundance of the evolved species.
• Indirect evolutionary effects on species abundances were as strong as direct effects.
• Cumulative evolution in multiple species antagonistically affected community composition and grazing but additively increased community biomass.

Conclusions:

• Focusing on single-species evolutionary effects can yield unreliable predictions for community-level eco-evolutionary dynamics.
• Simultaneous evolution in multiple species significantly alters community structure and function.