Generation: 0
Mean trait: 0.50
Mean pref: 0.50
Variance: 0.10
Fisher's runaway selection: female preference and male trait become genetically correlated.
Once established, both can evolve beyond natural-selection optima — a "runaway" process.
Zahavian handicap principle: costly signals (like the peacock's tail) are honest because
only high-quality males can afford them. The Lande 1981 model shows a "line of equilibria"
where natural and sexual selection balance.