Aging Reversed In Mice

Hugh Pickens writes "The Guardian reports that scientists claim to be a step closer to reversing the aging process after experimental treatment developed by researchers at Harvard Medical School turned weak and feeble old mice into healthy animals by regenerating their aged bodies. 'What we saw in these animals was not a slowing down or stabilization of the aging process. We saw a dramatic reversal – and that was unexpected,' says Ronald DePinho, who led the study. The Harvard group focused on a process called telomere shortening where each time a cell divides, the telomeres are snipped shorter, until eventually they stop working and the cell dies or goes into a suspended state called 'senescence.' Researchers bred genetically manipulated mice that lacked an enzyme called telomerase that stops telomeres getting shorter causing the mice to age prematurely and suffer ailments, including a poor sense of smell, smaller brain size, infertility and damaged intestines and spleens. When the mice were given injections to reactivate the enzyme, it repaired the damaged tissues and reversed the signs of aging raising hope among scientists that it may be possible to achieve a similar feat in humans – or at least to slow down the aging process."

Comments

Then the immortals ascended to the heavans

[t0qer]

While I see some folks saying "no one should live forever" let me ask you this... What about space travelers? Don't you think on 100+ year trips, living forever might be a good thing?

Re:Do not want

[RsG]

In the future: We can carry on with our fixed population size, imposed via whatever methods are "acceptable" and we will have options:

hate that I have to keep pointing this out, but clinical immortality will not lead to overpopulation, as counter-intuitive as that statement sounds, regardless of whether we limit our reproduction as a matter of public policy.

I'll break it down into three scenarios, in order of most to least likely. All three are based around methods for extending the human lifespan. In the first scenario, let's imagine a world where telomerase treatments reverse or mitigate cellular ageing.

Now, to begin with, this isn't "immortality", even in the ageless sense, as there would still be terminal illnesses and cumulative damage. Lifespans would increase, but would not be infinite. Cancer would probably beat out all other natural causes put together. So, let's say the average lifespan is a century or two.

The window of opportunity for having kids would remain mostly where it is now. This is because gametes age and run out regardless of the ageing going on in your other bodily tissues. A woman is born with a finite number of eggs, and they have an best-before date that has nothing to do with telomeres. Men would stay fertile longer, though not indefinitely, but the population growth rate is capped by the number of fertile females, not males.

Thus, the most likely scenario for anti-ageing drugs would not affect the rate of population growth rate, and would only increase the average lifespan by a limited margin. Given that the developed world is already at or below replacement level fertility, this would not pose a problem for the global population. And the developing world would need to modernize before they could implement this kind of medical care regardless, so they would probably also see a decline in growth to match our own, if history is any precedent.

Now, a second scenario would be perfect clinical immortality. No disease is terminal, no age related damage irreversible, no injury permanent. People only die traumatic deaths, whether by accident, violence or suicide.

The population still wouldn't skyrocket. People in the western world put off having kids already, generally waiting as long as natural fertility allows. How long would we put off having kids if we had no biological clock counting down? Decades? Centuries? A long time, regardless.

People still wouldn't live forever either. I've seen estimate that state that if death by old age vanished tomorrow, the average life expectancy would work out to about 300-500 years. Might be less if suicide became a common cause of death. And while the population might level out, the growth rate would slow to a crawl.

Now, the final option would be complete immortality. To accomplish this, we'd need to be able to make backups, against the risk of traumatic death. The mechanism for backing up a human being would almost certainly entail whole brain uploading.

With the capacity to upload brains comes the capacity to live without bodies. Overpopulation becomes supremely irrelevant if many or most of us live inside virtual worlds. And as far as that goes, given how technologically unlikely this scenario is, who's to say we'd even need Earth at this stage?