Life, Death and Energy: What Does Nature Select?

Area of Science:

• Evolutionary Biology
• Biophysics
• Ecological Energetics

Background:

• Evolutionary biology has undergone two major syntheses: Darwin's natural history and the incorporation of genetic mechanisms.
• A third synthesis is emerging, focusing on energy and biophysical processes as fundamental drivers of evolution.
• Existing evolutionary frameworks often overlook the quantitative role of energy in organismal success.

Purpose of the Study:

• To introduce and define the equal fitness paradigm (EFP) as a quantitative framework for evolutionary biology.
• To elucidate how natural selection optimizes energetic fitness, defined by biomass conversion into offspring.
• To explore the implications of the EFP for understanding organismal life histories and diversity.

Main Methods:

• Development of the equal fitness paradigm (EFP) equation: $$ = $$ * $$ * $$ * $$ .
• Analysis of steady-state conditions where energy content ($$ ≈ 22.4 kJ/g) and biomass ($$ ≈ 1 g/g) are conserved across generations.
• Examination of how natural selection acts on EFP parameters across diverse animal life histories.

Main Results:

• The EFP quantifies the energetic basis of survival and reproduction, demonstrating natural selection maximizes energetic fitness.
• Selection directly targets the parameters within the EFP, not necessarily isolated traits like metabolic rate or longevity.
• The paradigm explains why there is no inherent advantage to traits such as higher metabolic power, growth rate, fecundity, or longevity.

Conclusions:

• The EFP provides a unifying, energy-centric view of evolutionary processes and natural selection.
• Understanding energy acquisition and conversion is key to explaining the diversity of life.
• This biophysical approach offers a new foundation for evolutionary biology, integrating diverse life histories under a common energetic principle.