x_{n+1} = r·x_n·(1−x_n). Period-doubling route to chaos: stable fixed point → 2-cycle → 4-cycle → … → chaos. The ratio of successive bifurcation intervals converges to Feigenbaum's constant δ ≈ 4.6692. The Lyapunov exponent λ = lim (1/N)∑ log|r−2rx_n| distinguishes order (λ<0) from chaos (λ>0).