According to Lamarck 's long-discredited theory of evolution , anatomy will be structured according to functions associated with use; for instance, giraffes are taller to reach the leaves of trees . By contrast, in Darwinian evolution , form ( variation ) precedes function (as determined by selection ). That is to say in Lamarckian evolution the form is altered by the required function, whereas in Darwinian evolution small variations in form allow some parts of the population to function "better", and are therefore more successful reproductively.
Utilitarians disagree about whether judgments of right and wrong should be based on the actual consequences of actions or their foreseeable consequences. This issue arises when the actual effects of actions differ from what we expected. J. J. C. Smart (49) explains this difference by imagining the action of a person who, in 1938,saves someone from drowning. While we generally regard saving a drowning person as the right thing to do and praise people for such actions, in Smart’s imagined example, the person saved from drowning turns out to be Adolph Hitler. Had Hitler drowned, millions of other people might have been saved from suffering and death between 1938 and 1945. If utilitarianism evaluates the rescuer’s action based on its actual consequences, then the rescuer did the wrong thing. If, however, utilitarians judge the rescuer’s action by its foreseeable consequences (. the ones the rescuer could reasonably predict), then the rescuer—who could not predict the negative effects of saving the person from drowning—did the right thing.