We applied the second law of thermodynamics to provide proper physical foundations in biological evolution. We found that biological evolution transpires via oscillating state variables of entropy, energy, temperature, pressure, and volume. These fluctuations, parallel genetic and morphological complexity, include low entropy order increasing transformations and high entropy competition. Low entropy conditions favor maximum energy use, formulated by the maximum power principle. In contrast, high entropy states demand minimal entropy production and favor highly specialized species, as Prigogine's minimum entropy production theory shows. Our argument reconciles the contradictions between the two theories. In this framework, periodic mass extinctions act as pivotal reset points, removing highly specialized evolutionary dead ends while creating opportunities for renewal in surviving species. Identifying the contrasting energy profiles and entropic environments in which these two principles operate can aid a more in-depth understanding of the Darwinian Theory.