Actually, my assertion was based on the past rate and acceleration of progress in understanding the biological make up of humans and their relatives. Yes knowledge accumulation accelerates, at the beginning. But it also stagnates. Our understanding of animal design has been doing whatever it does for hundreds of years, and yet we are still fighting about the basics. Really.
In my professional opinion, we are in no danger of escaping our evolutionary design any time soon. I understand the impulse to hope, or even bet, otherwise. But the fact that you are certain means that you have yet to understand the nature of the challenge.
I certainly agree that anything natural selection has done is necessarily possible, and that, in principle it could all be duplicated. And beyond that, that everything natural selection has produced is ultimately based in physics. And yes, most of our best medical tricks involve repurposing products of selection. But none of it gets you where you want to go.
First off, my problem with your assertion was about the timeframe you placed on it and the certainty that you implied. We are not anything like 50 years away from doing what you are suggesting (either in terms of knowing enough about our construction, or in terms of having powerful enough tools to accomplish it), and even if we were somehow going to get there, you couldn't possibly be sure of it now, based on the current state of knowledge. Something utterly amazing and unforeseen would have to happen.
Further, I would say that the likelihood that humanity will survive long enough to get where you are suggesting is very small. We are much farther away than you imagine.
For now, the precautionary principle is the state of the art.
But i've also never seen a hummingbird in a subway tunnel, but I have little doubt that selection could produce one, given time and a niche worth inhabiting.
Unfortunately, there is no selection on hummingbirds to get more than a couple of hundred feet up so their absence from space doesn't really say much about the power of selection.
Still, even if I grant you that selection couldn't possibly put an animal into space, I see no comparison between the complexity, efficiency, robustness, effectiveness, etc. of a humming bird and that of a crude, inhabited space traveling projectile. Sure, technology does some interesting things. It even does a few things that selection couldn't, but your assertion that normal human concerns will be made technologically obsolete in fifty years is ridiculous.
Biologically, we're talking about a self assembling, self repairing, dynamic organism composed of 10 trillion cells. And we haven't even talked about the ability of the brain and the immune system to deal with novel challenges that are unprtecidented in the evolutionary history of the species in question! We're not anywhere close to understanding the basic rules of our own construction, let alone being able to overcome the built in costs of our marvelous design.
Natural selection does not favor traits that "help the species survive". It favors things that increase the rate at which individuals reproduce.
The fact that selection opposes aging (senescence) has been understood since 1957 (actually, earlier, but it has been thoroughly understood since then.)
I've put the relevant paper on line. It is by George C. Williams, one of the greatest evolutionary thinkers since Darwin. He is also the guy who cured evolutionary biology of the idea that selection acts to the benefit of the species.
We already have nanotech, infinitely more advanced than humans could conceivably devise in the next fifty years. We are made of it. And the machinery in question was created by a force that opposes aging, yet natural selection has not managed to solve the problem of aging, or cancer, or pathogenic disease. What mechanism do you think we will have access to that could possibly counter these major costs of our design? And you are willing to trust the utterly irreplaceable environment to the same, unspecified, technology?
Before you start waxing philosophic about technology's superiority to nature, take a moment to consider what a humming bird is capable of. And I don't just mean in terms of flight agility, I mean precision acrobatics, controlled by an onboard computer that asses the world in real time with staggering precision. And the whole thing runs incredibly efficiently on sugar.
Has man ever come within an order of magnitude of the marvel of a humming bird? So what makes the next fifty years, and the biological problems inherent to humans any different?
I don't mean "cure cancer" in the sense of eliminating existing cancers, I mean eliminate the phenomenon. I'm arguing that cancer comes with the territory once you have extensive self repair.
I like your phone booth argument. In fact, I made roughly that argument in the paper that I pointed to above. Here is how I put it:
"Finally, given our increasing ability to detect and surgically or chemically eliminate tumors, we might one day be willing to accept an increase in our tumor risk in order to extend youth. The in vitro lengthening of zygote telomeres would likely produce that heritable effect."
An anti-cancer booth is a great image.
Tumors are cell lines that have escaped the telomere failsafe because a second mutation has activated telomerase (an enzyme that lengthens telomeres), thus "unhooking" the failsafe that protected us in the first place.
Apoptosis is a second line of defense, but not nearly so effective because it requires that tumor cells are distinct enough from normal cells that the suicide program can be initiated. If the criteria used by cells to determine if they are cancerous (and thus need to self destruct) is too sensitive, then healthy cells get destroyed, accelerating aging. If if the criteria are not sensitive, then tumors get out of contol without triggering the alarm. Still, a problem with no sollution.
An adult human is composed of roughly ten trillion cells. A self repairing organism (one in which cells replace themselves) running around in an environment full of mutagenic agents, is in constant danger that one of those cells will be damaged in such a way that it just keeps dividing. In principle, nearly all of those ten trillion cells can initiate a deadly tumor at any moment.
The most probable reason that cancer is so terribly rare in the young is that the great bulk of our cells have a failsafe mechanism built in. They can only divide a finite number of times before they "arrest" and stop dividing. Runaway cell lines only get so big before they stop growing. There is no reason that cell division needs to be limited other than as a tumor failsafe. Its an evolutionary adaptation. A long lived, highly complex, self repairing, ten trillion cell organism would not be possible without it. But it limits the amount of repair you can do in a lifetime. That's why we age.
further, it is becoming clear that natural selection has balanced tumor risks, with repair concerns and extended our maximum longevity as much as we can hope for. You can cure cancer, if you are willing to age at a high rate. You can cure aging, and degenerate into a mass of tumors. But the idea that we are going to have to worry about the social implications of doubling human lifespans is laughably premature.
Want to know more. Check out this paper on the subject.
Or visit Telomere.org
Slashdot Mirror
I'm fairly new to slashdot and it looks to me like my reply appended to the wrong message. Is that true, or does it just look that way?
Actually, my assertion was based on the past rate and acceleration of progress in understanding the biological make up of humans and their relatives. Yes knowledge accumulation accelerates, at the beginning. But it also stagnates. Our understanding of animal design has been doing whatever it does for hundreds of years, and yet we are still fighting about the basics. Really.
In my professional opinion, we are in no danger of escaping our evolutionary design any time soon. I understand the impulse to hope, or even bet, otherwise. But the fact that you are certain means that you have yet to understand the nature of the challenge.
I certainly agree that anything natural selection has done is necessarily possible, and that, in principle it could all be duplicated. And beyond that, that everything natural selection has produced is ultimately based in physics. And yes, most of our best medical tricks involve repurposing products of selection. But none of it gets you where you want to go.
First off, my problem with your assertion was about the timeframe you placed on it and the certainty that you implied. We are not anything like 50 years away from doing what you are suggesting (either in terms of knowing enough about our construction, or in terms of having powerful enough tools to accomplish it), and even if we were somehow going to get there, you couldn't possibly be sure of it now, based on the current state of knowledge. Something utterly amazing and unforeseen would have to happen.
Further, I would say that the likelihood that humanity will survive long enough to get where you are suggesting is very small. We are much farther away than you imagine.
For now, the precautionary principle is the state of the art.
But i've also never seen a hummingbird in a subway tunnel, but I have little doubt that selection could produce one, given time and a niche worth inhabiting.
Unfortunately, there is no selection on hummingbirds to get more than a couple of hundred feet up so their absence from space doesn't really say much about the power of selection.
Still, even if I grant you that selection couldn't possibly put an animal into space, I see no comparison between the complexity, efficiency, robustness, effectiveness, etc. of a humming bird and that of a crude, inhabited space traveling projectile. Sure, technology does some interesting things. It even does a few things that selection couldn't, but your assertion that normal human concerns will be made technologically obsolete in fifty years is ridiculous.
Biologically, we're talking about a self assembling, self repairing, dynamic organism composed of 10 trillion cells. And we haven't even talked about the ability of the brain and the immune system to deal with novel challenges that are unprtecidented in the evolutionary history of the species in question! We're not anywhere close to understanding the basic rules of our own construction, let alone being able to overcome the built in costs of our marvelous design.
Not everyone who sees limits is a moron.
Natural selection does not favor traits that "help the species survive". It favors things that increase the rate at which individuals reproduce.
The fact that selection opposes aging (senescence) has been understood since 1957 (actually, earlier, but it has been thoroughly understood since then.)
I've put the relevant paper on line. It is by George C. Williams, one of the greatest evolutionary thinkers since Darwin. He is also the guy who cured evolutionary biology of the idea that selection acts to the benefit of the species.
We already have nanotech, infinitely more advanced than humans could conceivably devise in the next fifty years. We are made of it. And the machinery in question was created by a force that opposes aging, yet natural selection has not managed to solve the problem of aging, or cancer, or pathogenic disease. What mechanism do you think we will have access to that could possibly counter these major costs of our design? And you are willing to trust the utterly irreplaceable environment to the same, unspecified, technology?
Before you start waxing philosophic about technology's superiority to nature, take a moment to consider what a humming bird is capable of. And I don't just mean in terms of flight agility, I mean precision acrobatics, controlled by an onboard computer that asses the world in real time with staggering precision. And the whole thing runs incredibly efficiently on sugar.
Has man ever come within an order of magnitude of the marvel of a humming bird? So what makes the next fifty years, and the biological problems inherent to humans any different?
If you were kidding, I guess the joke's on me.
Yeah, sorry. I wasn't clear.
I don't mean "cure cancer" in the sense of eliminating existing cancers, I mean eliminate the phenomenon. I'm arguing that cancer comes with the territory once you have extensive self repair.
I like your phone booth argument. In fact, I made roughly that argument in the paper that I pointed to above. Here is how I put it:
"Finally, given our increasing ability to detect and surgically or chemically eliminate tumors, we might one day be willing to accept an increase in our tumor risk in order to extend youth. The in vitro lengthening of zygote telomeres would likely produce that heritable effect." An anti-cancer booth is a great image.
I think we are just having a miscommunication.
Tumors are cell lines that have escaped the telomere failsafe because a second mutation has activated telomerase (an enzyme that lengthens telomeres), thus "unhooking" the failsafe that protected us in the first place.
Apoptosis is a second line of defense, but not nearly so effective because it requires that tumor cells are distinct enough from normal cells that the suicide program can be initiated. If the criteria used by cells to determine if they are cancerous (and thus need to self destruct) is too sensitive, then healthy cells get destroyed, accelerating aging. If if the criteria are not sensitive, then tumors get out of contol without triggering the alarm. Still, a problem with no sollution.
Human aging is almost certainly such a problem.
An adult human is composed of roughly ten trillion cells. A self repairing organism (one in which cells replace themselves) running around in an environment full of mutagenic agents, is in constant danger that one of those cells will be damaged in such a way that it just keeps dividing. In principle, nearly all of those ten trillion cells can initiate a deadly tumor at any moment.
The most probable reason that cancer is so terribly rare in the young is that the great bulk of our cells have a failsafe mechanism built in. They can only divide a finite number of times before they "arrest" and stop dividing. Runaway cell lines only get so big before they stop growing. There is no reason that cell division needs to be limited other than as a tumor failsafe. Its an evolutionary adaptation. A long lived, highly complex, self repairing, ten trillion cell organism would not be possible without it. But it limits the amount of repair you can do in a lifetime. That's why we age.
further, it is becoming clear that natural selection has balanced tumor risks, with repair concerns and extended our maximum longevity as much as we can hope for. You can cure cancer, if you are willing to age at a high rate. You can cure aging, and degenerate into a mass of tumors. But the idea that we are going to have to worry about the social implications of doubling human lifespans is laughably premature.
Want to know more. Check out this paper on the subject. Or visit Telomere.org