Dar animalele complexe și-au obținut flexibilitatea adaptativă cu un cost-au tranzacționat o dependență pentru alta. Nu mai era necesar să -și schimbe corpul pentru a se adapta, deoarece acum adaptarea lor era comportament, determinat social. Acest comportament a necesitat învățarea. Într -un anumit sens, printre animale superioare, fitnessul adaptativ nu mai era transmis deloc generației următoare de către ADN. Acum a fost purtat prin predare.
(But complex animals had obtained their adaptive flexibility at some cost--they had traded one dependency for another. It was no longer necessary to change their bodies to adapt, because now their adaptation was behavior, socially determined. That behavior required learning. In a sense, among higher animals adaptive fitness was no longer transmitted to the next generation by DNA at all. It was now carried by teaching.)