In the book of Genesis, the Bible routinely records human lifespans which seem outrageously different from our experience today. Adam lived to 930 years; Noah even longer, to 950 years (see graph below). These long lifespans are not haphazardly distributed; they are systematically greater before the Flood of Noah, and decline sharply afterwards.
These great ages are not presented in the Bible as if they are in any way extraordinary for their times, let alone miraculous.
Many people are quick to scoff at such ages, claiming they are ‘biologically impossible’. Today, even if they avoid all fatal diseases, humans will generally die of old age before they reach much past 100. Even the very exceptional cases don’t make it much past 120 years.
However, a look at the evidence related to aging suggests that the apparent upper limit on today’s average lifespans is not something that is ‘biologically inevitable’ as such for humans or other multi-celled creatures.
Disease, diet, ‘wear and tear’ and other environmental factors undoubtedly play a part in how long we live. However, it now appears that underlying all these are factors somehow written into our genetic code, which determine what our ‘upper limit’ is. This is not really surprising; most of us know of families in which nearly everyone lives to a ripe old age—and the opposite, of course.
And although an average ‘upper limit’ seems to be ‘programmed’ into each species, breeding experiments have shown that this limit can be altered, even dramatically. Experiments with fruitflies and worms have shown that extra longevity can be bred into and out of these populations. So you can have two populations of the same fly, with one group living many times longer than the other, on average. Even a genetic ‘switch’ involved in longevity has been identified in one species of worm.