Bioenergetic trophic trade-offs determine mass-dependent extinction thresholds across the Cenozoic

Area of Science:

• Ecology
• Evolutionary Biology
• Bioenergetics

Background:

• Body size is a fundamental ecological factor influencing trophic interactions and population dynamics.
• Macroevolutionary patterns of body size and diet are shaped by ecological constraints and feedback loops.

Purpose of the Study:

• To explore how bioenergetic trade-offs in predator-prey interactions constrain species coexistence.
• To identify the feasible size range for terrestrial predators and understand factors influencing dietary selectivity.

Main Methods:

• Development of a bioenergetic, three-level trophic framework simulating terrestrial mammalian ecosystems.
• Analysis of population stability under varying predator-prey interactions and resource subsidies.
• Modeling the relationship between body size, dietary selectivity, and fitness in carnivores.

Main Results:

• Trophic interactions destabilize populations at both small and large body sizes, defining limits to predator size and diet.
• A feasible predator size range of approximately 40-110 kg was identified, consistent with Cenozoic hypercarnivores.
• Reduced dietary selectivity benefits larger carnivores, with this advantage diminishing at the largest sizes.

Conclusions:

• Ecological pressures from trophic interactions, driven by energetics, are key selective forces in macroevolution.
• The study provides insights into the coevolution of body size, diet, and ecological interactions in mammalian predators.
• Observed macroevolutionary patterns in predator size and diet are explained by bioenergetic constraints and trophic dynamics.