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Aging Process May Be Reversable, Scientists Claim (theguardian.com)
New submitter TheNinjaCoder writes: A new type of gene therapy is showing promise in reversing the aging process. The scientists are not claiming that aging can be eliminated, but say that in the foreseeable future treatments designed to slow the process could increase life expectancy. The Guardian explains the scientists' experiment in its report: "The rejuvenating treatment given to the mice was based on a technique that has previously been used to 'rewind' adult cells, such as skin cells, back into powerful stem cells, very similar to those seen in embryos. These so-called induced pluripotent stem (iPS) cells have the ability to multiply and turn into any cell type in the body and are already being tested in trials designed to provide 'spare parts' for patients. The treatment involved intermittently switching on the same four genes that are used to turn skin cells into iPS cells. The mice were genetically engineered in such a way that the four genes could be artificially switched on when the mice were exposed to a chemical in their drinking water. The scientists tested the treatment in mice with a genetic disorder, called progeria, which is linked to accelerated aging, DNA damage, organ dysfunction and dramatically shortened lifespan. After six weeks of treatment, the mice looked visibly younger, skin and muscle tone improved and they lived 30% longer. When the same genes were targeted in cells, DNA damage was reduced and the function of the cellular batteries, called the mitochondria, improved. Crucially, the mice did not have an increased cancer risk, suggesting that the treatment had successfully rewound cells without turning them all the way back into stem cells, which can proliferate uncontrollably in the body." The study has been published in the journal Cell.
"Overpopulation can be dealt with by moving people to other planets"
Or, we could just gradually lower our fertility rate as life extension catches on. This normally takes place anyway when an agrarian society industrializes and the five children per family become two.
Genetic disorder mitigated by genetic manipulation. Yes?
Instead of progeria-afflicted mice, why not attempt the technique on otherwise healthy mice? If that can be made to result in a 30% lifespan extension, that would be notable.
"The team also saw improved organ health in normal mice but, because the mice are still living, could not yet say if longevity was extended."
http://www.nytimes.com/2016/12...
Congratulations! But even if you have the cure for aging you'll have to solve some (quite big) problems:
* The danger of overpopulation. If old people don't die, and young people keep making babies, our planet will become overcrowded soon. Which system should be implemented? A policy where you need permit by the government to have babies? Will we make a gigantic ponzi scheme where we put those extra humans on mars, then on other plantes, colonizing the galaxy? What when the whole galaxy is colonized? Intergalactic travel outside of our local group is quite hard, as expansion of space will make those galaxies leave us faster than light before we can get to them.
* The danger of cancer. Often when rejuveniating cells you put them in a mode where they like to multiply. You artificially increase the likelihood for cancer with this to an extent of almost certainity.
The summary specifically mentions that they found no increased chance of cancer and besides cancer and overpopulation are not reasons not to pursue it. If you could keep someone healthy to 150 and then just took them out in the streets and shot them that would be preferable to what we have now which is where a 100 year old is frail and decrepit.
There are other problems too that need to be dealt with. Society changes because the older generation dies out. If you think the top .01 percent of the rich are bad now, imagine how much worse it would get if they never died and could continue to amass wealth and power indefinitely.
Overpopulation can be dealt with by moving people to other planets.
No it can't. At current birth rates, you'd need to move about a million people off planet every week. To put that in perspective, every day roughly 100K people get on planes at London Heathrow. That means that your spaceport would have slightly more departures to space then Heathrow has to terrestrial destinations, every day. Most travellers at Heathrow have under 20Kg of luggage: you're talking about permanent emigration, where people would need a lot more. Let's be conservative and say 100Kg of baggage allowance per person, making a total of about 100Kg. The energy cost to geosync orbit is 50 MJ/Kg. Assuming that in your future world, you have a 100% energy efficient solution (and you have a magical space drive to take them somewhere else), that's 10,000MJ (10GJ) per person, or 10PJ per week.
Now, to put that in perspective, that's about a tenth of the total world energy production currently, just to lift these people and a modest amount of baggage to orbit, using an unfeasibly efficient system and assuming that your magical space elevator is a sunk cost. This sounds almost feasible, but it has a number of unfeasible assumption. Current power beaming (the method of choice for powering a space elevator) is 0.5% efficient and scientists hope to get it up to 2%. That multiplies your energy cost by 50 and means that you're now talking about using five times the current total world power output just to lift people to orbit.
Now, you might say, if you have a space elevator then you could power it using photovoltaics in Earth orbit. Okay, let's look at that. We'll assume 40% efficient solar panels (about the theoretical maximum for photovoltaics). That gives us 400W/m^2. To get our 500PJ/week, we need a constant supply of around 825GW, or a square of solar panels 45km on each side, along with all of the associated cabling and infrastructure. That might just about be possible to build, once you have the space elevator running (though assuming 1Kg per square metre panel, with estimated costs of space elevator operation, it would cost around $400bn in today's dollars, so not exactly a cheap project).
And that's just to get people up to orbit. If you want to actually get them to another planet, you're going to need enough interplanetary ships to carry them somewhere else. And then there's the question of where you send them. Mars? Even if you terraform it, it has the same land mass as Earth, so even if you ignore the children of the colonists then it will fill up in about the time it would take the population of the Earth to double, so that's only going to buy you a few decades.
Since we're talking future hypotheticals, let's say that we find exoplanets with a compatible biosphere and develop a faster-than-light drive (and we'll not even think about the energy costs of that). Unless you reduce the birth rate, the human population is still going to keep doubling every few decades, so all of those newly colonised planets are going to start exporting people soon too. You'll need to double the number of human colonies every few decades and unless human-friendly planets are startlingly common, that's not sustainable. And if you do manage to reduce birth rates to a manageable amount, then the need to export people from Earth goes away.
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