Natural selection cannot possibly produce any modification in a species exclusively for the good of another species; though throughout nature one species incessantly takes advantage of, and profits by the structures of others.
Hautespen naturalak ezin du eraldaketarik eragin espezie batengan beste espezie baten onerako soilik, naturan espezie batzuek beste batzuen egituratik etengabe abantaila jaso eta etekina ateratzen duten arren.