History
August Weismann was responsible for interpreting and formalizing the mechanisms of Darwinian evolution in a modern theoretical framework. In 1889, he theorized that aging was part of life's program because the old need to remove themselves from the theatre to make room for the next generation, sustaining the turnover that is necessary for evolution. This theory again has much intuitive appeal, but it suffers from having a teleological or goal-driven explanation. In other words, a purpose for aging has been identified, but not a mechanism by which that purpose could be achieved. Aging may have this advantage for the long-term health of the community; but that doesn't explain how individuals would acquire the genes that make them get old and die, or why individuals that had aging genes would be more successful than other individuals lacking such genes. (In fact, there is every reason to think that the opposite is true: aging decreases individual fitness.) Weismann disavowed his own theory before his life was over.
Theories suggesting that deterioration and death due to aging are a purposeful result of an organism's evolved design (such as Weismann's "programmed death" theory) are referred to as theories of programmed aging or adaptive aging. The idea that the aging characteristic was selected (an adaptation) because of its deleterious effect was largely discounted for much of the 20th century, but is now experiencing a resurgence because of new empirical evidence as well as new thinking regarding the process of evolution.
Read more about this topic: Evolution Of Ageing
Famous quotes containing the word history:
“Those who weep for the happy periods which they encounter in history acknowledge what they want; not the alleviation but the silencing of misery.”
—Albert Camus (1913–1960)
“No cause is left but the most ancient of all, the one, in fact, that from the beginning of our history has determined the very existence of politics, the cause of freedom versus tyranny.”
—Hannah Arendt (1906–1975)
“Every generation rewrites the past. In easy times history is more or less of an ornamental art, but in times of danger we are driven to the written record by a pressing need to find answers to the riddles of today.... In times of change and danger when there is a quicksand of fear under men’s reasoning, a sense of continuity with generations gone before can stretch like a lifeline across the scary present and get us past that idiot delusion of the exceptional Now that blocks good thinking.”
—John Dos Passos (1896–1970)