>As I recall, however, this gentleman had a great deal of
>trouble calculating his true age, as records in his town were not
>kept well back then. But by projecting it based on the details of
>his childhood, this is the number they came up with.
The overwhelming cause of remarkable age in humans is faulty
reporting. The ages of very old people get stretched with
time - somebody did a study demonstrating that the age claimed
for people over 85 goes up 17 years every decade. The age
calculation for this man obviously is very unreliable.
Because of the reporting problems, the agency that assigns
the "oldest human" title has become quite anal about verification.
The best claim for breaking Calment's record to my knowledge
is a woman in Brazil who is supposedly about 128. Actually
she does have some documentation, but not as much as that
agency now demands.
>I also don't know about that 140 estimate--I'm seeing 120 batted
>around as our potential lifespan, barring serious disease or injury.
Potential lifespans aren't absolute; the chance of death never goes
to 1. With humans the chance of death seems to max out at about
40% per year or so. With enough people, or enough luck, you could
probably get any age you wanted; it's just that the number of people
or amount of luck required goes up fast and exponentially. At
40% deaths per year, if you get a maximum of 122 with 5 billion
people, you would expect 132 with 1 trillion. So if economic
or logistical constraints limit the size of your lifespan studies
the maximum lifespan will be fairly constant - strain effects
will far outweigh these statistical variatons. Some guys did a 1
million medfly mortality study recently - and blew away the
previous species maximum lifespan, which had been based on studies
of thousands of flies.