Reason is creating relationships between realities. Whenever relationships are made, consistent relationships support each other, and inconsistent relationships contradict each other. So the former increase, and the later decrease. The increase in consistent relationships is the evolution of reality. Only the consistent relationships can cause realities to become large and complex.
Inconsistent relationships cause realities to break up into small and conflicting pieces.
Consistent relationships create a unified reality. Evolution is an increase in unified reality. God has the deck stacked through material conditions causing unified reality increase when realities interact. The primary factor causing that result was the use of molecules which stabilize realities. Once stabile realities exist, their interaction will increase unified reality.