There are developments that could (and probably will) lead to humans being able to live forever. But is it desirable?
A naturally occurring substance found in the soil of Easter Island, in the southeastern Pacific Ocean, is the latest discovery in Man’s ongoing quest for the elixir of youth. Rapamycin may extend the life expectancy of laboratory mice but, despite the recent hype, there is no evidence that it will do the same for us. It will, however, give researchers a better understanding of why we age — a process that they hope one day to be able to slow or stop. And there is growing optimism that their work is more science fact rather than science fiction.
Ageing is not inevitable. The sea anemone is an example of a species that never appears to age, and there is tremendous variation in life expectancy among animals. Most voles won’t make their first birthday, while a giant tortoise can live to well over 150.
The average life expectancy of a British human being lies almost exactly halfway between these two extremes, with most of us alive today expected to make it well into our eighties — a figure that has risen over the past century as a result of better nutrition, living conditions and healthcare. And this increasing longevity has also been associated with better quality of life. The latest evidence suggests that people who die at 90 spend roughly the same amount of time in hospital as those who die in their seventies, and only twice as long as those who die in their mid-forties.
But to make further inroads into extending our life expectancy we need to do more than negate hazards such as disease and accidents. We need to slow the ticking of our genetic clocks.
At the moment even the best cared for human being is unlikely to make it much beyond 120 because the body’s natural repairing processes grind to a halt and whole systems start to fail.
Our tissues don’t have a pre-programmed best-before date, but their inbuilt repair processes do, and it is these that largely determine the rate at which we age. Our basic software — DNA — is particularly sensitive to damage, with an attack rate that has been estimated at 10,000 damaging hits per cell, per day. Multiply this figure by the one hundred thousand billion or so cells in the average human body and you get some idea of the challenge faced by our repair systems. Suffice to say there is a bit more to them than healing cuts and grazes.
The onslaught comes from all directions — everything from sunlight to tobacco smoke — but the main villain is oxygen. We need it to create energy, but in the same way that it turns a newspaper yellow and iron rusty, it also eats away at our structure.
Constant repair uses up a lot of energy and can weaken the processes involved, as demonstrated by what happens when our chromosomes divide during cell replication.
To prevent damage to the DNA during cell renewal, chromosomes contain special structures called telomeres that protect the delicate strands as they unravel and reform. Think of them as the plastic caps on the ends of your shoelaces. The more times the DNA is “tied” and “untied”, the shorter the telomeres become until, perhaps after 100 renewals, the telomeres disappear altogether and the DNA starts to fray. And that is the beginning of the end for the cell.
So, one way to think of our life expectancy is to consider that we are only as old as our telomeres. The longer they are, the longer you are likely to live, and vice versa, as children with the rare condition progeria discover to their cost. A child with progeria is born with unusually short telomeres (roughly the same as those normally found in a 70 or 80-year-old) and ages at an incredible rate, with few living beyond their early teens.
Unfortunately, human adult cells don’t have any way of repairing damaged telomeres, so cell death is inevitable, but a repair enzyme — telomerase — does exist in sperm and the female egg. Researchers in America have managed to insert the genes that produce it into adult skin cells and two years later they were still happily dividing without their telomeres getting any shorter.
Producing a potentially immortal skin cell in a Petri dish in a lab is a long way from significantly extending human life expectancy, but it is a step in the right direction and the solution is likely to come from genetic engineering rather than from some as-yet-undiscovered natural panacea. And it is not so much if, as when.
Any such breakthrough is going to happen too late to help most of us — something that I am actually quite pleased about, as I have no desire to live for ever. I just want to enjoy a full and active life before dropping dead quite unexpectedly some time in my eighties.
Galaxy Poll: 86 per cent of Australians want childhood vaccination to be compulsory? 2015-04-17 23:33
Australians want Prime Minister Tony Abbott to make childhood vaccination compulsory and close loopholes that allow vaccine refusers to put all children at risk.
An exclusive national Galaxy poll commissioned by The Sunday Telegraph has revealed overwhelming support to ensure every child is vaccinated.
The highest support for compulsory jabs is in South Australia, where 90 per cent support the call.
The poll ...
Eye in the sky: Local police now using drones to spy on citizens 2015-04-17 22:09
The Harris County Precinct 1 Constable's Office is doing something that no other agency in Harris County is believed to have done yet: Use drones to help fight crime.
It's an eye in the sky for law enforcement, without giving up the element of surprise.
"It could absolutely save lives," says Constable Alan Rosen.
Rosen says the agency's two new $1,200 drones, which ...
New Zealander of the Year: refuse vaccines, lose money 2015-04-17 22:47
Following in the footsteps of Australia, 2014 New Zealander of the Year, Dr. Lance Oâ€™Sullivan, wants to punish people who donâ€™t get vaccinated.
The New Zealand Herald (4/15) reports:
â€śA leading New Zealand doctor has called on the Government to follow Australiaâ€™s example to cut child welfare payments to families who do not vaccinate their children, saying the policy would help protect ...
Iris Scanner Identifies a Person 40 Feet Away 2015-04-17 22:20
Police traffic stops are in the news again, tragically, sparking a new round of discussion on whether and how to outfit police with cameras and other technology.
For several years now, researchers at Carnegie Mellon Universityâ€™s CyLab Biometrics Center have been testing an iris recognition system that can be used to identify subjects at a range of up to 40 feet.
Yes, You Can Catch Insanity 2015-04-17 22:29
One day in March 2010, Isak McCune started clearing his throat with a forceful, violent sound. The New Hampshire toddler was 3, with a Beatles mop of blonde hair and a cuddly, loving personality. His parents had no idea where the guttural tic came from. They figured it was springtime allergies.
Soon after, Isak began to scream as if in pain ...