Egg size evolution and energetic constraints on population dynamics.

Area of Science:

• Ecology
• Evolutionary Biology
• Population Dynamics

Background:

• Understanding the evolution of reproductive strategies is crucial for predicting population dynamics.
• Dynamic energy budget models provide a framework for linking individual physiology to population-level outcomes.
• Offspring size represents a key life-history trait influenced by trade-offs.

Purpose of the Study:

• To investigate the evolution of offspring size using individual-based dynamic energy budget models.
• To explore the relationship between offspring size evolution and population dynamics.
• To test model predictions against empirical data for Daphnia magna.

Main Methods:

• Utilized dynamic energy budget models to simulate individual energy allocation.
• Developed population models incorporating offspring size and time-to-maturity trade-offs.
• Analyzed the emergence of evolutionarily stable strategies for offspring investment.
• Compared model outputs with observed egg energy data in Daphnia magna.

Main Results:

• Identified alternative evolutionarily stable strategies for offspring investment, balancing number and maturity time.
• The model accurately predicts egg energy levels in Daphnia magna.
• Offspring size evolution is influenced by selection for minimal viable egg energy and juvenile reserves.
• Selection for minimal egg size can drive populations towards chaotic dynamics.

Conclusions:

• Population dynamics are shaped by the evolution of offspring size and investment strategies.
• Minimal viable egg size and low energy conversion efficiency can stabilize population dynamics, preventing chaos.
• The interplay between individual energy budgets and population-level constraints governs evolutionary outcomes.