 The idea that the ageing characteristic was selected (an adaptation) because of its deleterious effect was largely discounted for much of the 20th century, but a theoretical model suggests that altruistic ageing could evolve if there is little migration among populations.Weismann later abandoned his theory and later followed up with his "programmed death" theory.Natural selection is a process that allows organisms to better adapt to the environment, it is the survival of the fittest which are predicted to produce more offsprings.