He led life step by step down a path that took it from primeval simplicity to contemporary complexity, similar to Darwin’s evolutionary tree of life (fish begot amphibians who begot reptiles who begot birds and mammals, etc).
Unti-unti, Kanyang pinamunuan ang paglikha mula sa pagiging simple sa unang panahon hanggang sa pagiging kumplikado sa makabagong panahon, tulad ng "evolutionary tree of life" ni Darwin (mula sa isda naging ampibyan na naging reptilya na naging ibon at mamalya, at iba pa).