Every species seems to have a certain "maximum" lifetime range. This is the life expectancy of animals in optimal circumstances, such as the top of the hill predator or an animal (like the elephant) that is mostly invulnerable as adults or an animal kept as a pet or in a good zoo.
Most animals have a "typical" life expectancy much shorter than that, among adults, and this is a function of predation pressure.
Now enter natural selection, whose goal is not so much to preserve the animal (although this is usually the story) as it is to optimize the genes that get passed on down the generations. When there is heavy predation, there is no point in having genes that enhance life beyond. Further, when there is heavy predation, natural selection has a small interest in clearing the decks for the next generation.
Compared to other mammals of our size range, human beings live far longer than most. This seems to have been steadily getting longer through prehistory and even a little through history. As predation and disease and accidents continue to take lives early, while the maximum life span is getting longer, further natural lengthening would require even less early death. (There is also a "grandmother theory" that is seen by many as helping explain the longer maximum lifespans in human beings).
All this indicates that there is an inherited genetic component in aging rates and maximum life spans. Probably a number of genes involved, but, regardless, over time we should be able to identify those genes and do something about them.
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