Developmental cost theory predicts thermal environment and vulnerability to global warming

Area of Science:

• Ecology
• Evolutionary Biology
• Physiology

Background:

• Metazoan development from zygotes to feeding organisms requires substantial energy, up to 60% of parental investment.
• Both metabolic rate (energy use) and developmental rate (duration) are temperature-dependent, influencing overall developmental costs.

Purpose of the Study:

• To develop and test a physiologically explicit theory of developmental cost.
• To identify the optimal thermal window (T_opt) for minimizing developmental costs in ectotherms.
• To predict species' vulnerability to environmental warming based on developmental cost sensitivity.

Main Methods:

• Development, parameterization, and testing of developmental cost theory.
• Estimation of T_opt for 71 species across seven phyla.
• Comparison of predicted T_opt with natural thermal environments.

Main Results:

• Developmental cost theory accurately predicts the natural thermal environments of studied species (R² ~0.83).
• Developmental costs are more sensitive to temperature changes than survival rates.
• Tropical aquatic and non-nesting terrestrial species are predicted to face the greatest increases in developmental costs due to warming.

Conclusions:

• Developmental cost theory provides a mechanistic framework for understanding species' responses to climate change.
• Warming-driven increases in developmental costs can significantly impact population replenishment.
• Identifying species at risk requires understanding their specific thermal optima and sensitivity to temperature fluctuations.