SETI bioastro: Salon article On Immortality

From: Larry Klaes (lklaes@bbn.com)
Date: Mon Apr 17 2000 - 06:36:32 PDT


Date: Mon, 03 Apr 2000 10:03:14 -0400
From: "J. Hughes" <jhughes@changesurfer.com>
Reply-To: transhumantech@egroups.com
Subject: [transhumantech] Salon.com on immortalist tech

salon.com > Health & Body March 30, 2000

URL: http://www.salon.com/health/feature/2000/03/30/immortal

On immortality

- - - - - - - - - - - -
By Susan McCarthy

One of the pleasing prospects that's ballyhooed as a future benefit of the
Human Genome Project is in-creasing human longevity. The trouble with
longevity is that if you go waltzing far enough down the path of long life
you might find that you have merged with the highway of immortality without
stopping at the weigh station of wisdom. Is that a perfectly good thing?

Can longevity extension go past combating diseases and address the very
process of aging itself? If not, longevity will be less attractive. If, on
the other hand, we can stay forever young, we may never want to leave the
party. Should all of us be allowed to hang around as long as we want? Even
creeps?

Research that may bear on the practical end of these matters is proceeding
with startling speed.

Dr. Francis Collins, director of the National Human Genome Research
Institute at the NIH, told the Washington Post that within 30 years we'll
know all the genes involved in the human aging process.

He cited an experiment in which manipulating one gene in a mouse extended
the mouse life span by 30 percent. "Without manipulation, it seems that the
maximum human life span is about 100 years. It is pos-sible that could be
extended if we understand the pathways of aging better," he said. He added
that there are many ethical questions "that would have to be addressed
before applying this on a broad scale." (I know people who already wish to
sign up for the narrow scale.)

The elderly mice in question are Italian, and were engineered to be
deficient in p66shc, a protein that tells a cell to self-destruct when it
has sustained too much damage from free radicals (molecules produced
throughout the body in the process of oxygen metabolism). This is thought
to be a defense against the possibility that the damaged cells will become
cancerous. But without p66shc, the mice live 30 percent longer. (Being
mice, whose lives are brief, this means a few extra months of mousy joys.)

Dr. Huber Warner, director of the biology of aging program at the National
Institute on Aging (NIA) is also optimistic about the Human Genome Project
and the outlook for living longer. "The fruit-fly genome has just been
sequenced. Now, if you look at genes known to be involved in diseases,
two-thirds of those genes are found in the fruit fly, including some very
important genes that are tumor-suppressor genes."

NIA is investing millions in research to find genes in animals like fruit
flies or mice "which when mutated or expressed differently will alter the
life span of those species," says Warner. "Now if you can identify those
genes in model organisms, then the sequence of the human genome will give
you the information you need to begin to extrapolate. We will figure out
ways to manipulate the genes in the model organism and it'll suggest how
those genes can be manipulated in humans."

Organizations like the NIA and the American Federation for Aging Research
emphasize that they are not interested in increasing life span so much as
increasing "health span," the years people can live with vi-tality, dignity
and comfort.

Another avenue age scientists are racing down is telomere research.
Telomeres are tasteful strands of non-sense DNA that decorate ends of
chromosomes. Each time a cell divides, a bit of the telomere is clipped
off. Eventually, when the telomere is a mere buzz-cut stubble, the cell
stops dividing. There's a way around telomere loss: an enzyme called
telomerase, which adds on extra telomere each time it's snipped shorter, so
that it stays the same length, and the cell is not signaled to stop
dividing. Scientific American has said telomerase "may well be the elixir
of youth."

Some human tissues that divide indefinitely, such as reproductive cells
producing sperm and eggs, contain telomerase. So do cells in embryos, but
the telomerase gene is inactivated in most cells after birth.

Reactivating telomerase could replenish lost cells. Warner mentions the
possibility of restoring epithelial cells in the retinas to restore lost
eyesight. Telomerase genes have been successfully reactivated in retinal
epithelial cells grown in tissue culture, in work done at the University of
Texas Southwestern Medical Center and the Geron Corporation. Geron has
filed for patents on hTRT, the telomerase reverse transcrip-tase protein.
Warner notes, "The problem with turning telomerase back on is that's one of
the things that happens in cancer." Cancer cells are all about telomerase
and unrestricted cell division.

Steven Austad is a zoologist who studies aging. In his lucid, engaging book
"Why We Age," he describes his study of opossums on a Georgia barrier
island -- Methuselah opossums who had smaller families, of-ten bred two
years in a row instead of one, and aged more slowly, living a whopping
three years instead of two.

Austad notes that when we discover and examine genes in the human genome
that can increase longevity, they may prove to come with trade-offs. "Of
all these genes in these small animals [that extend longev-ity], none of
them are ever found in nature. And they all have downsides. People have not
been eager to investigate the nature of their downsides."

Cancer obviously could be a downside, as could altered fertility.

Austad says he's been snorted at by other scientists when he argues that we
should study the cells of long-lived animals like whales and elephants
instead of short-lived ones like mice and fruit flies if we want to
understand how we might live longer. "Elephants contain about 40 times the
numbers of cells we do, and whales as many as 600 times as many cells. Yet
elephants and whales live, to a reasonable approximation, just as long as
we do. Therefore, their cells must be 40 to 600 times more resistant to
turning cancerous than our own. Could we perhaps learn something about
cancer resistance from studying these cells?" he has written.

So far, Austad himself isn't working with elephants. Instead he's looking
at parakeets. "They live up to 20-plus years," he says admiringly. "That's
seven times as long as a mouse, and they're the same size. They have
unbelievable resistance to oxidative damage ... if we could somehow mimic
that in humans ..."

So, downside or no, Austad also thinks findings from the Human Genome
project will help us increase human longevity. "We already know that there
are some genes that are associated with longer life in ani-mals. I think
we'll find the [corresponding] genes in humans that have a small but
measurable effect on how long we live. And it won't be too many years
before we have gene therapy for all kinds of things. It hasn't worked too
well yet, but that's just a technical problem."

Is there any theoretical limit that would keep increased longevity from
becoming immortality? Warner says "There's no theoretical limit. There's a
balance between constant damage and repair. It's like a car. Theoretically
you should be able to keep a car going forever -- not yours, maybe, and not
mine -- but if you keep replacing the parts the car could last forever.
Maybe the individual could live forever."

"The only limit is that there is no such thing such as immortality because
accidents still happen," says Austad. "The theoretical limit is human
behavior, not human physiology. If teenagers didn't drive cars like crazy
people, that would probably have more effect on life expectancy than curing
cancer."

Dr. Leonard Hayflick takes a darker view of longevity research than many
scientists do. Hayflick's view of significantly increased longevity is,
basically, that it won't happen, it can't happen, and if it did happen it
would be a bad thing.

Hayflick, a professor of anatomy at the University of California at San
Francisco's school of medicine, is the author of "How and Why We Age," and
has been thinking about longevity for 30 years, ever since he discovered
what's now called the Hayflick Limit. Until his research, it was thought
that animal cells growing in tissue culture were immortal and could divide
forever. In a series of meticulous experiments, Hayflick showed that normal
cells in culture have life spans: They flourish and divide for a while, but
after a certain number of generations, divide no longer and eventually die.
The cell lines that do go on forever are cancer cells.

People fail to distinguish between curing disease and ending aging,
Hayflick says. If all the diseases cur-rently written on death certificates
in developed countries were resolved, you could add perhaps at the most 15
years to human life expectancy. "And that's it. Period."

Aging itself will not be affected. "Aging is an inexorable process that
begins at about the age of 30 in hu-mans and continues indefinitely. If you
resolve disease you then expose or reveal the underlying real cause of that
vulnerability, and hence death."

Hayflick doesn't believe that we will be able to go beyond resolving
disease to slowing or stopping the process of aging. You can replace parts
all you want he says, but what will you do when you have to re-place your
brain?

It's true that people object to aging as well as to death. Long life, while
much admired, isn't sought after so much as long healthy life, or perhaps
long youth. We want to be 100 years old and dewy fresh.

Dr. Pier Paolo Pandolfo, one of the scientists who studied the mice that
live 30 percent longer, told the New York Times that a drug to block the
self-destruct protein p66shc (the one the mice were engineered not to have)
could be applied in the form of a cream to reverse wrinkling and blemishes
on aging skin.

Can we have both long life and long youth? "I would say that there's no
question about that," says Austad. "Most people would say that if you can't
have better function there's no sense in keeping people alive."

It's increasingly easy to imagine replacing our parts, renewing our
tissues, and rewriting our DNA. We would also need to fix our memories.
They can hold a great deal, but never needed to hold an infinite amount of
experience. Yet there are various ways we might deal with that, such as
adding memory chips to our brains. Or perhaps we'll even figure out how to
get rid of unneeded, unpleasant old memories and provide room for
delightful new memories. It'll be doable, eventually.

Is this really possible? I believe it is, though I'm not fool enough to
suggest a timetable. To those who say it'll never happen, I say: Don't
confuse "a hell of a long time" with never. I think rather highly of human
ingenuity and biological science. I see no reason why we won't eventually
learn how to live forever and to live forever young.

I think less highly of collective human common sense. (As Kay tells Jay in
that brilliant philosophical work, "Men in Black," "A person is smart.
People are dumb ...) And so there's no reason to suppose we will handle
this knowledge wisely.

Why aren't we immortal already? If it's so easy to turn on a gene here and
turn off a gene there, why do we wear out and die? It's all about
reproduction, of course. Once we've produced the next generation and gotten
them on their feet, what happens to us is of no relevance to the future.
People who have two chil-dren and live to be 100 are less successful from
an evolutionary standpoint than people who have three children and keel
over in their 50s.

So the impressive genes that allow people to reach 100 on a diet of bacon
and beer are not favored by natural selection. (Although if the
centenarians spend all their time calling up their great-grandchildren and
asking when they're going to have babies and the great-grandchildren cave
in and produce more chil-dren than they otherwise would have, that might
favor those genes a bit.)

Still, it seems a little odd that there are no immortal species around.
Quahogs live to be 200, but they probably feel that's not nearly long
enough. Perhaps species of immortal animals would always be out-competed by
species of mortal animals, since mortal species evolve and acquire exciting
new bells and whistles to repel insect pests, protect against disease and
fool dinosaurs into thinking you wouldn't dream of eating their eggs.

If we stop dying will our species stop evolving? Not if we keep
reproducing. Not everyone thinks we need to keep evolving. Many of us feel
that we are already the pinnacle of perfection and that all our spe-cies
needs to do is stay as sweet as we are. Others disagree.

My friend Cynthia Heimel says she does not feel we are nearly finished
evolving, and she is eagerly looking forward to an era when we have
progressed to having just four toes on each foot. She says it is because
little toes are no use and catch on the bed corner, but I believe she just
wants to wear pointier shoes.

In the choice between living long and having kids, natural selection has
always favored having kids. Now that choice will be up to us. Obviously if
we choose to do both, the world will fill up with people to such an extent
that we'll have to look for new planets.

We will ourselves become natural selection -- unnatural selection if you
prefer. Instead of allowing the ceaseless cherry-picking of the generations
to get rid of our back problems, our impetuous driving habits and that
pesky fifth toe, we will do it all at once with gene therapy.

Will everyone get to live forever, or will we make decisions about how long
people get to live and when they have to stop?

This is one of the reasons Hayflick thinks increasing longevity is a
dreadful idea. "I defy anyone to de-scribe a scenario in which it would be
a good thing," he says.

Hayflick told the Savannah Morning News, "If indeed we had a way of
extending human longevity the probability is very high that therapy would
be available to the rich and powerful. I don't know how you feel about the
rich and powerful, but I can think of lots of them that I would not like to
see live forever." For example, he notes, "I don't think that having Adolf
Hitler around for the next 500 years makes much sense."

You know Fidel Castro isn't ready to die. And while I am under the
impression that I have accepted my own mortality, I must admit that I don't
accept the mortality of my loved ones. It's not that I want them to be
immortal, it's just that I don't want them ever to die.

The fact that we spend such a huge proportion of our health budget in the
last few months of our lives is testimony to this. (As my father remarks,
"You can't tell what truly expensive way of living a little longer will be
discovered.")

Spending money on gene therapy will undoubtedly be more popular than the
feeble unappealing ways we have now of extending life span a little. You
know, boring stuff like eating right, keeping fit, signalling your lane
changes.

There are some things people won't do to live longer, after all. Yes, we'll
slam down melatonin, DHEA and random antioxidants by the fistful just in
case they slow aging. But almost nobody has leapt on the caloric
restriction bandwagon (which holds that since rats on meager diets live
longer, maybe we would too, so let's not eat anything at all every other
day), because it's so unpleasant.

I have also heard men complain about how unfair it is that women live
longer on the average. (Some of them will glare at a lady as if she'd been
sprinkling free radicals on their salads.) Yet although it has long been
known that castration can extend a man's life span by an average of 14
years, guys consistently pass on the chance to even the score.

Is it any more unnatural to use gene therapy to become more or less
immortal, than it is to use prolong life in other ways? After all, during
most of human history most children died as infants, women couldn't
ef-fectively limit how many children they gave birth to (and were far more
apt to die in childbirth), and very few of them reached old age -- yet
hardly anybody objects to medical care to fight these causes of death.

But what all these changes amount to for our species is simply a movement
along the spectrum from the kinds of species that have brief risky lives in
which they produce as many progeny as possible -- like mice -- to the kinds
of species that have longer lives during which they have fewer progeny, in
whom they in-vest more parental care -- like elephants. These life
strategies are called r selection and K selection, and there's nothing so
unusual about a species becoming more or less K-selected.

But among all the variously r- and K-selected creatures in the world, one
thing seems constant: Every-body dies eventually. Immortality is something
different.

Then there's the matter of addressing ethical conflicts before we proceed.
The track record on this is not so great. Conferences are held and panels
meet and people go right ahead and do what they want. And people really
really want to live. "If it becomes possible, people will do it," says
Steven Austad.

There are people worrying now about the way better health care is producing
an unprecedentedly large population of older people, and the effects this
has on medical spending, education spending, Social Secu-rity and the GNP.
Oh, and the ballot box.

Well, they haven't seen anything yet. The world will fill up a lot faster
if nobody dies.

Maybe we'll make people choose between living forever and having kids. If
you're going to bring more people into the world, you'll have to be willing
to leave it yourself on a reasonable schedule. Conversely, if you refuse to
leave the party, you can't bring crashers. Of course, this would create an
interesting two-tiered world full of crabby child-haters who think they
know so much because they've seen it all and breeders speaking smugly about
how they're being not only natural but also more evolved.

What about natural selection? It got us this far, didn't it? If immortality
is a bad idea, won't nature take care of it? It might do just that, but not
in way we'll enjoy. Since natural selection is mindless and pur-poseless,
it has no objection to dead ends and short-term successes. Eventually some
species could come along which has all our excellences, plus the advantages
of mortality, and it will eliminate us. Not if we can stop them first, of
course, but eventually (and this is a very long run indeed) we will be
out-competed. Will the new Lords of the Earth then turn to making
themselves immortal? Very likely, but it won't be our problem. Mother
Nature doesn't care, ahistorical, short-sighted fool that she is.

Perhaps in the far reaches of time, as one mortal species after another
crushes species that have suc-cumbed to the temptation of eternal life, a
species will arise that will remain mortal, and will allow itself to
change. Perhaps they will never be overthrown by another species. Perhaps
they'll have a zoo, and we'll be in it, and will learn the full reality of
a life sentence.

salon.com | March 30, 2000

- - - - - - - - - - - -

About the writer
Susan McCarthy is a San Francisco freelance writer and the author, with
Jeffrey Masson, of "When Elephants Weep: The Emotional Lives of Animals."



This archive was generated by hypermail 2b30 : Wed Mar 28 2001 - 16:07:53 PST