Discussing Evolutionary Theories that Explain Aging

Allowing old critters to hang around indefinitely and to continue having offspring actually slows down the development of new types. The result would be species with less adaptability. We get all of the benefit we need by having a reasonably long siring/birthing period in a finite lifetime.

For centuries, beginning with Aristotle, scientists and philosophers have struggled to resolve this enigma. The Roman poet and philosopher Lucretius, for example, argued in his De Rerum Natura (On the Nature of Things) that aging and death are beneficial because they make room for the next generation (Bailey 1947), a view that persisted among biologists well into the 20th century. The famous 19th century German biologist, August Weissmann, for instance, suggested — similar to Lucretius — that selection might favor the evolution of a death mechanism that ensures species survival by making space for more youthful, reproductively prolific individuals (Weissmann 1891). But this explanation turns out to be wrong. Since the cost of death to individuals likely exceeds the benefit to the group or species, and because long-lived individuals leave more offspring than short-lived individuals (given equivalent reproductive output), selection would not favor such a death mechanism.

Oh, thanks. Wait arent you an ID supporter?

I think the question that CoolBeans is posing here is why we age biologically. The issue isn't really why we die; it's why we undergo senescence, and how this can be reconciled with natural selection.

nwr writes:In terms of a society, the older members of a community provide a degree of cultural memory, often in the form of traditions and folklore. That the older member eventually die, allows the culture to evolve to better fit changing conditions.I'm just describing what I see as what would have affected evolution.

Oh, thanks. Wait arent you an ID supporter?