Consumer-resource dynamics is an eco-evolutionary process in a natural plankton community

Area of Science:

• Ecology
• Evolutionary Biology
• Limnology

Background:

• Eco-evolutionary dynamics, where ecological changes drive rapid evolution and vice versa, are well-established in lab settings.
• These dynamics are significant for understanding natural ecosystem functioning, particularly in aquatic environments.
• Daphnia, a key zooplankton consumer, influences seasonal plankton dynamics and is sensitive to shifts in its phytoplankton food source.

Purpose of the Study:

• To investigate the role of eco-evolutionary dynamics in a natural lake ecosystem.
• To examine how seasonal changes in phytoplankton composition affect the evolution of Daphnia populations.
• To understand the feedback between Daphnia evolution and seasonal plankton dynamics.

Main Methods:

• Field observations and experiments in Oneida Lake, New York.
• Monitoring seasonal shifts in phytoplankton communities (e.g., diatoms, cyanobacteria).
• Assessing evolutionary changes in Daphnia mendotae populations, specifically their tolerance to cyanobacteria.

Main Results:

• Seasonal shifts in phytoplankton from edible algae to inedible cyanobacteria were observed.
• Daphnia mendotae populations evolved increased tolerance to cyanobacteria within a single year.
• This evolutionary adaptation by Daphnia influenced the seasonal population dynamics of this consumer.

Conclusions:

• Eco-evolutionary dynamics are important drivers of community functioning in natural ecosystems.
• Rapid, within-year evolution in consumers can alter ecological dynamics.
• The observed consumer-resource dynamics in Oneida Lake suggest such processes are common in mesotrophic lakes.