Re: Re : Nature Special on Aging

Date: Mon Nov 13 2000 - 10:52:13 MST

In a message dated 11/13/00 9:33:48 AM, writes:

>My understanding of our aging goes about like this:
>1. We are doubling our knowledge about once in three and a half years.
>2. We are not able so far to make great improvements in the maximum
>age for a human being.
>3. We have made and are making significant improvements in the quality
>of life for the people over say sixty five years of age.
>4. We are making increases in the average lifespan due to more people
>living longer although less than the maximum age for a human.

>Is the above approximately correct?

Yes, except that maximum age isn't a very precise model for organisms like
people. A more precise model is that we have a base health (base
chance of dying per year) and an aging rate (doubling time for the
death rate). Maximum lifespan is an epiphenomenon; for any given
set of parameters and finite population size you will eventually see
everyone from a given cohort dead. Some organisms like salmon
do have a genuine maximum lifespans arising from direct biological
processes and not as a statistical epiphenomenom.

So far we have improved our base rate of dying but not our aging rate.
This increases both our life expectancy and maximum lifespan, at a
rate of 1 to 2 years per decade (depending on whose data and
statistical models you use). This corresponds with changes we've
had from other apes; their aging rates are very similar to ours but
their base health is orders of magnitude less. These differences
may be due to culture rather than biology; rather than being
healthier than other apes we just take care of ourselves better.

This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:50:21 MDT