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Physics Makes Aging Inevitable, Not Biology (2016)
- Tepix 9y agoIf we manage to reset the age of our biological cells, their DNA may change over time but that doesn't mean it's infeasible or a dead end.
- matte_black 9y agoWe can worry about physics based aging when we've gotten biological aging under control.
- contravariant 9y agoThis article argues they are one and the same.
- jcadam 9y agoWell, you know, peel away enough layers of abstraction and everything is "just physics."
- davidkuhta 9y agoFTFY: ...everything is "just mathematics." ;) https://xkcd.com/435/ https://xkcd.com/435/
- matte_black 9y agoMath makes aging inevitable, because every moment that passes increments the amount of total time we’ve been in existence.
- rowyourboat 9y agoThe headline's premise does not square with the fact that there are organisms that don't age and whose life span is only limited diseases, accidents and predation. https://en.wikipedia.org/wiki/Negligible_senescence https://en.wikipedia.org/wiki/Negligible_senescence That strongly points toward a biological reason for aging. I mean, sure, the heat death of the universe is inevitable, but that is not even remotely on the same time scale as the life span of complex organisms.
- contravariant 9y agoMaybe the headline is somewhat flawed, but objects with negligible senescence are discussed in the article. According to the article the only difference between organisms with and without negligible senescence is whether there is a possibility for damage to accumulate.
- Karlozkiller 9y agoBut wouldn't aging be exactly that damage accumulation? Are we then not saying 'not aging is impossible, here are some examples of things not aging' ?
- IntronExon 9y agoAging is a “planned” process, damage is just damage. Shortening telomeres with reproduction, cell senescence, loss of reproductive viability are not damage, they’re age related. UV light knocking a base pair out of a whack is damage. If you live long enough, you will accumulate damage even in the absence of aging. The hope for humans is thst we develop means to both halt aging, and repair accumulated damage.
- rowyourboat 9y agoWhere exactly does he discuss that? His entire point seems to be that aging is inevitable: > The constant risk is environmental (accidents, infectious disease), but much of the exponentially increasing risk is due to internal wear. ... but as examples of negligible senescence show, that is simply not the case. This "exponentially increasing risk" is just not a given.
- saalweachter 9y agoThe author gets into it in the comments (which are now two years old at this point?).
- brlewis 9y agoThat none of the longest-lived organisms are warm-blooded squares well with the article's premise that physical heat damage causes aging.
- RobertoG 9y agoI'm not sure what is the message of the author here. Entropy always increase in closed systems, but we are not talking about a closed system here. My understanding is that, from the point of view of physics, there is not a reason for not being possible to decrease entropy in the body increasing entropy outside (expending energy). Also, this is untrue: "DNA can only be repaired when there is an intact replica to copy". If you have, for instance, three incorrect copies of a DNA sequence you can compare them in order to get the original sequence. The probability that the copies are damaged at the same point being very small.
- amelius 9y agoThere are also some theories on proton decay, which could be considered a source of "physical" aging, but the timescales are extremely large.
- rtkwe 9y agoYeah, if we get to the point where humans (or whatever our evolutionary progeny are can't imagine it'd be anything resembling humans today) are still around when that starts happening at 10^28 years which is ~10^17 years from now I'll consider that a job extremely well done as a species/civilization.
- AnimalMuppet 9y ago10^28 years is ~10^17 years from now? I think you either typoed or your math is faulty...
- rtkwe 9y agoI just messed up the math. It should be 10^19. Either way it'd be an unqualified success.
- AnimalMuppet 9y agoI still think you're incorrect. If we're at 10^13 years, then 10^28 minus 10^13 is, essentially, 10^28 years from now. > Either way it'd be an unqualified success. Certainly. I'm just picking nits on the math.
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- reasonattlm 9y agoEntropy arguments for the primacy of aging are fairly silly. For one, there are actually species that appear to be essentially immortal. Secondly, the germline. Cellular systems are clearly capable in principle of indefinitely maintaining themselves against entropy by either asymmetric division in which molecular waste is partitioned into one child cell (single cell life) or leveraging asymmetric division to replace worn parts with good parts (multicellular life). To explain why aging exists and is so prevalent in biology one has to look at the level above physics, and that debate largely takes place in the overlap between evolutionary biology and molecular biochemistry. The germline and hydra must be brought forward every time someone says that aging is an inevitable, universal consequence of thermodynamics: http://www.demogr.mpg.de/en/news_press/press_releases_1916/forever_young_4396.htm http://www.demogr.mpg.de/en/news_press/press_releases_1916/f... The common perception that the bodies of all living beings age, is wrong. This has now been proved by a long-term experiment with the freshwater polyp Hydra, a microscopic animal. In a unique long-term experiment researchers created artificial conditions for the tiny water animals with their flimsy tentacles, which were free of fatal natural threats like predators. For almost ten years they have cared for of about 1,800 of the Hydras. Overall, the team has counted 3.9 million observation days of individual Hydra. The number of natural deaths per year, however, can be counted on one hand. On average there have been only five. When a Hydra passed away it was mostly due to laboratory accidents, such as a polyp sticking to the lid of its bowl and then drying up or simply having been dropped on the floor. From of the few natural deaths that remained researchers calculated Hydra's mortality. It is so low that even several lifetimes of researchers would not suffice to observe the end of the lifecycle of the polyps. Even after 500 years five percent of a cohort will still be alive. For two out of twelve of the Hydra cohorts under investigation, the risk of death was actually so small, that it will take 3,000 years until only five percent of the polyps remained. "Hydra apparently manages to keep its body young because it does not senesce by accumulating damages and mutations, as most other living beings do. Hydra are probably able to follow a special self-preservation strategy, as its body and cellular processes are rather simple." For instance, Hydra are capable of completely replacing parts of the body that are damaged or are somehow lost. It can even fully regenerate if its body is destroyed almost completely thanks to a high number of stem cells. Stem cells are capable of developing into any part of the body at any time. Additionally, as Hydra replaces all of their cells within only four weeks, it regularly and quickly expels all cells that have been changed genetically by mutations. Thus, damages have little chance to accumulate. Current thinking on why near all species fail to behave like hydra looks somewhat like this: http://arxiv.org/abs/1103.4649 http://arxiv.org/abs/1103.4649 Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory: i) competition is between individuals; ii) there is some degree of locality, so quite often competition will between parents and their progeny; iii) optimal conditions are not stationary, mutation helps each species to keep competitive. When conditions change, a senescent species can drive immortal competitors to extinction. This counter-intuitive result arises from the pruning caused by the death of elder individuals. When there is change and mutation, each generation is slightly better adapted to the new conditions, but some older individuals survive by random chance. Senescence can eliminate those from the genetic pool. Even though individual selection forces always win over group selection ones, it is not exactly the individual that is selected, but its lineage. While senescence damages the individuals and has an evolutionary cost, it has a benefit of its own. It allows each lineage to adapt faster to changing conditions. We age because the world changes.
- justonepost 9y agoSo how is it that green land sharks can live 400 years? Or the Great Basin bristlecone pine is like 5K years? And what about https://en.wikipedia.org/wiki/Biological_immortality https://en.wikipedia.org/wiki/Biological_immortality
- Numberwang 9y agoLand Sharks? Help!
- EGreg 9y agohttps://i.ytimg.com/vi/sUOifHlxGiw/hqdefault.jpg https://i.ytimg.com/vi/sUOifHlxGiw/hqdefault.jpg
- brlewis 9y agoThe Greenland Shark keeps its cells in the refrigerator its whole life: https://en.wikipedia.org/wiki/Greenland_shark https://en.wikipedia.org/wiki/Greenland_shark I imagine the internal temperature of the Great Basin bristlecone isn't that high either. However, see another thread on this article where someone mentions Naked Mole Rats, warm-blooded animals with long lifespans.
- stareatgoats 9y ago> "If this interpretation of the data is correct, then aging is a natural process that can be reduced to nanoscale thermal physics—and not a disease. " (my italics). To me this is the main problem with this article. The (ever more common) notion that aging is a disease should be combated with philosophical arguments, not shaky physics such.
- vanderZwan 9y agoHalf-serious, half-joking, but I think that procreation and death are nature's way using the "have you tried turning it off and on again?" approach to evolving multicellular life. It's probably the most cost-efficient, all things considered.
- fwdpropaganda 9y agoMost cost-efficient for what purpose?
- imtringued 9y agoIncrease entropy.
- fwdpropaganda 9y agoNo one has the purpose of increasing entropy. And you're not the person I was asking anyway.
- vanderZwan 9y agoFor change and adaptation to new contexts. Unless you know of a way to turn an elephant into a fly and back. I mean that literally. For battling decay. It can be easier to grow a new body from a single cell, than to keep patching up a running one. A desire for immortality is the individual point of view. In the big picture of things, there is little to no selection pressure for immortality. There is plenty of selection pressure for adaptation and change, and death and rebirth are effective tools for that.
- stinos 9y agoI always considered biology, chemistry, ... to ultimately be applied physics. So nothing new here :]
- fwdpropaganda 9y agoComplete bollocks. Molecules don't age and everything in your body is molecules. If a molecule breaks down, in some cases the body has mechanisms to replace it with a shiny new one. Those mechanisms are themselves made of molecules. And if those mechanisms to stop working, in some cases those mechanisms can also be replaced. Nothing in fundamental physics makes aging inevitable. From what I can tell, the reason why aging is so prevalent is that most species haven't had time to evolve the mechanisms that solve the problems that appear later in life. If there's some truth to this, you'd expect that the species that are better at this also tend to be the simpler ones, since for those simplicity also means smaller diversity of things going wrong.
- rubenbe 9y agoNature has not been able to solve the problem of ageing because natural selection does not work at later age. The organism has already successfully procreated, so there is no survival of the fittest.
- fwdpropaganda 9y agoNot true. Procreation is not binary. More is better (evolutionarily speaking), so there's no reason for "once you have one offspring you're evolutionarily dead." No, you could have more.
- XorNot 9y agoOn some level humans are the pinacle of the solution to survivability. We live in every biome on the planet, and are actively researching giving ourselves immortality. We're so successful that the best strategy for a lot of other animals has been to be food or company. Cows are doing pretty well because of us.
- kabouseng 9y agoNot really, if you stay young forever you can procreate forever and "out" procreate the rest of your species that still ages.
- razorunreal 9y agoI think they've got the evolutionary argument backwards. Rather than the older generation aging and dying because there is some evolutionary reason why they should, I think there is simply not a strong enough reason why they shouldn't. Why fix the remaining aging bugs when you already live long enough to reproduce and pass on knowledge?
- klmr 9y agoBoth arguments exist, although I don’t think the “ageing was actively evolved” argument has ever gained a lot of mainstream traction: it’s not very parsimonious (all the available evidence can also be explained by the simpler model).
- dade_ 9y agoThis article is very informative about the challenges that biology contends with, but it doesn't convince me that the headline is true.
- ecpottinger 9y agoDon't forget the latest research on mole rats. http://experimentalbiology.org/getattachment/2014/About-EB/Press/Press-Releases/Rodriguez-Buffenstein-Release-FINAL.pdf.aspx http://experimentalbiology.org/getattachment/2014/About-EB/P...
- stochastic_monk 9y agoSenescence is a biological, not oxidative or thermodynamic, phenomenon. More oxidation, more metabolism, and more turnover gives you more chances to break down/accumulate mutations/shorten telomers, but that’s an artefact of cells running out of their means for rapid growth. These can be modified. Look, for example, at the countless immortalized cell cultures. It is a biological problem with roots in statistical and biomolecular physics, like literally everything else in biology.
- subroutine 9y agoI think if one is to pose this as an acceptable theory on aging they must explain why it doesnt apply to germ cells. The germline of an organism manages to escape these fundamental laws of physics to achieve 'immortality' simply by having more efficient DNA repair mechanisms than somatic cells. And so, imo, we are back to a biological explaination of aging.
- JepZ 9y ago> Nanoscale thermal physics guarantees our decline, no matter how many diseases we cure. If that is true, I wonder what the total live expectancy for our species is. I mean shouldn't stem cells be affected by that too?
- cornholio 9y ago> it is difficult to see how natural selection could have selected for senescence, because we don’t reproduce in our elderly years and natural selection is driven by differences in reproduction rates That's an entirely backwards way to look at the problem: selection works with living organism and the only reason an organism lives or performs a particular function is that it was evolutionary useful to do so for it's genes. Aging therefore is something natural selection can't discern on: at some point, the number of additional offspring that can be produced becomes negligible compared to the exponentially increasing probability of death from environmental causes (just like the test tube example); so organisms that quickly reproduce young are much more successful than long lived organisms. It's easy to see then, why the long term accumulating damage, irrelevant for a young organism, can't be evolved out of. We are essentially "single use" from an evolutionary standpoint. Therefore, advanced age (anything exceeding useful reproductive life) is something outside evolution. Anything happening at senescence time is simply a byproduct of the mechanism selected for ensuring success at young age, a system that continues to work by momentum and not design or selection, up to the inescapable moment when entropy catches up to it. But there is no fundamental physical reason for it, and it stands to reason we could create biological machines that maintain the power to self repair indefinitely, given suficient outside energy. It's just enormously more complex than "curing aging", it means artificially redoing billions of years of evolutionary choices that were good enough for reproduction. It's a God level task.
- perlgeek 9y agoThere are second-level effects where longevity can increase gene frequency: In a social species like humans or some whale species, the presence of parents and even grandparents can have positive effects on the survival of offspring, long after the older generation has stopped producing offspring. I don't know evolutionary biology enough to estimate how big of a selection pressure that is, though. Maybe much lower than first-order effects, maybe not so much. > But there is no fundamental physical reason for it, and it stands to reason we could create biological machines that maintain the power to self repair indefinitely, given suficient outside energy. Agreed.
- cornholio 9y ago
- vectorEQ 9y agoits silly to seperate biology and physics, seems to me that biological systems are also physical systems. other then that, stress causes aging. people who reduce stress keep their mind younger and often live longer and are less effected by diseases common among aging biological systems. ofcourse, stress then isn't the root cause of aging... as stress takes many forms, what causes stress is. so the answer to what causes aging is probarbly not a single point or item, but a combination of factors which all cause some form of stress on the system.
- c0nan69 9y agoOur life is an oxidation
- pipio21 9y agoWhile it is obvious that everything decays, it is equally obvious that you can repair it. For me eternal youth will happen sooner or later, probably 100 years in the future,50 years,200, but it will happen when we understand biology and could repair tissues, something that we could not do today. Today we don't heal a bone fracture, we let nature do it, because we really do not control or understand the process deeply. The body knows how to kill viruses, we do not. Only bacteria after copying nature with antibiotics is under our control but we do not control or understand the process again. This is not being immortal, people will die in wars, or accidents, or being killed, but they will be young all our lives. For this people will probably have to go to a place that resembles the uterus and spend some time there as the body repairs itself: https://pm1.narvii.com/6320/0940afb810563b4c4b67c4efb773adc00b0de312_hq.jpg https://pm1.narvii.com/6320/0940afb810563b4c4b67c4efb773adc0... After that you will be 20 years younger. Not different from repairing a car.
- FooBarWidget 9y agoWe can't even repair our own machines to the point that they last forever. I doubt we'll reach eternal youth any time soon, so I do think that we can lengthen life span quite a bit (low-hanging fruits) before we hit a wall that take even longer to surpass.
- sytelus 9y agoEach cell in our body is derived from a cell that existed 3 billion years ago. It seems twisted argument that some how cell in an individual body must die but can renerate for billions of years if it only met with other damaged cell. There are fair amount of examples such as a-sexual bacterial reproduction where cell essentially survives for ever. There are many species known to live on for multiple of 100 years.
- tomq 9y agoThis is an interesting article, but the core argument that aging is an inevitable result of physics and not biology has a counterexample. It’s the biologically immortal hydra: https://en.m.wikipedia.org/wiki/Hydra_(genus) https://en.m.wikipedia.org/wiki/Hydra_(genus)
- sseth 9y agoWe age for the same reason that code bases go bad over time - the accumulated cruft of tech debt overwhelms the ability of different parts of the system to work together well. This is a problem of any dynamic system, not something related to physics.
- neals 9y agoWell if you really want to talk hard-core Physics... isn't aging inevitable because of the eventual heat death of the universe?
- Pica_soO 9y agoI never dared to ask- but- do cancer cells age? How does a tumor behave if he gets to live longer then its own behaviour would allow to expect?
- Balgair 9y agoCancer is a strange beast. Some types of tumors do not 'age' like usual, some are 'hyper aged', some die off at incredible rates, but reproduce at even higher rates. Really, cancer cells are so wracked with errors and DNA damage, typically, that they really aren't the species that they grew up in anymore. For one instance, some tumor metabolisms are radically different than what is 'normal', more different than even what is seen in even prokaryotes: https://en.wikipedia.org/wiki/Warburg_effect https://en.wikipedia.org/wiki/Warburg_effect
- lawlessone 9y agoIf this were true how would we reproduce?
- jostmey 9y agoI wish I could download this because it is so wrong. There's been a lot of amazing work in biology explaing why aging exists. It has nothing to do with physics
- frlnBorg 9y agoThermodynamics and entropy, while causing decay in the long-term, have nothing to do with human decay over the span of 80-90 years. Arguing that entropy is THE fundamental cause of death just shuts down the conversation.
- ordu 9y agoA "causation" is an illusion. We can think, for example, that cause of ageing is in the evolution: those species who lives longer have slower evolving rate, and they lose a competition with other species who have shorter lives. But this causation does not contradict to the thermodynamic one, it just make thermodynamic not the "fundamental cause" but the mechanism of ageing. A causation is the way to describe reality, not the fundamental feature of the reality. And so, the causation should follow the goals of researchers. While searching for ways to live forever, we will not benefit from evolutionary explanation (we cannot fix evolution to get longer lives), but thermodynamics explanation could be useful (if its true, of course). So, thermodynamics is a good candidate for the role of "fundamental cause".
- saool 9y agoPhysics Makes Flying Impossible, Not Biology
- thefounder 9y agoNobody wants to live forever...just until the universe ends. I would gladly give the physics gods back my particles so that they can start a new big-bang!
- rossdavidh 9y agoSometimes, you can improve the software best by patching, sometimes by reefactoring. And eventually, as it gets older and bad traits accumulate, it becomes easier to do The Big Rewrite. That doesn't mean that it is impossible to fix the legacy code, just that at some point you're better off starting from scratch, but with the old one as a pattern to go off of. Aging and reproduction feels like the same pattern. Sure, you may be attached to the legacy code, but sometimes it makes more sense to do the big rewrite instead. Legacy code performed well for its time, now it is time to retire it.
- saalweachter 9y agoI think this is a subject that is ripe for appeals to consequence. People concerned about aging would really, really prefer there was a biological cause for aging. If it's biological, there's a chance there's a trivial fix (gene therapy, supplements, ...) for it, or at least a trivial incremental fix that will get you an extra ten or twenty years while you wait for the next incremental fix to be developed for the next problem down the line. If the problem is physical, caused by the wear and tear of your metabolism, the problem becomes significantly harder. Not impossible (after all, cell lines can be immortal, trivially, we have an unbroken line of single celled organisms dating back billions of years), but you are potentially looking at rebuilding mammalian life from the ground up before you make even incremental progress. And the only maybe-possible-but-the-animal-models-are-mixed incremental fix we have is to lower your metabolism by living your entire life on a calorie-restricted diet, or maybe by being just a little too cold all the time. I'm all for still devoting a healthy amount of resources to trying to find easy biological fixes to aging, because I'm old enough now that probably nothing else would happen fast enough to keep me, personally, alive, but if it turns out most of the problems are physical, we shouldn't shy away from acknowledging that just because it makes the work of beating death harder. We aren't trying to beat aging because it seemed like an easy thing to do.
- jugg1es 9y agoEvolution has selected for tons of different mechanisms and strategies for combating the decay and dissolution of organic molecules. This author doesn't seem to have read a lot of literature on how powerful these DNA repair proteins can be.
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- ilaksh 9y agoSee http://www.sens.org http://www.sens.org
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- rweba 9y agoTwo points: (1) I haven't seen this article mentioned here: https://gravityandlevity.wordpress.com/2009/07/08/your-body-wasnt-built-to-last-a-lesson-from-human-mortality-rates/ https://gravityandlevity.wordpress.com/2009/07/08/your-body-... I am not sure if the article addressed this model in particular, but I found it compelling. (2) It occurred to me that most of us don't fear death as much as becoming increasingly useless as we become older due to ill health and physical weakness. It would be not much fun living to be 200 if the last 120 years were spent in a bed or wheelchair. So what we want is not to increase the lifespan but to prolong the amount of time we can spend in relatively physically prime condition. I am sure this is not an original thought, but something worth mentioning.
- jadedhacker 9y agoIn medicine, this concept is referred to as "healthspan".
- JoshTriplett 9y ago> It would be not much fun living to be 200 if the last 120 years were spent in a bed or wheelchair. While I agree (and while I additionally think any plausible advancement of that degree would necessarily need to increase healthy lifespan), I'd also say that it'd be inherently preferable to dying, and it would give 120 more years to solve those problems. We can come up with a lot of medical advancements in 120 years.
- didgeoridoo 9y ago> Many researchers studying specific diseases, cellular systems, or molecular components would like to see their favorite research subject take the mantle of “the cause” of aging. But the sheer number of possibilities being put forward refutes the very possibility. They can’t all be the cause of aging. https://en.wikipedia.org/wiki/Fallacy_of_the_single_cause https://en.wikipedia.org/wiki/Fallacy_of_the_single_cause
- scythe 9y agoA friend did his PhD in the thermodynamics of open systems -- the sort of thing that describes, say, the long-term evolution of a "thing" that occasionally consumes and rejects energy. One thing he mentioned to me was being contacted by lots of crackpots, each with their own new idea wrt what open system thermo means about living organisms. It's a very new and very difficult field and there aren't hard results yet. I would take this article with a shaker of salt, and perhaps some tequila, lime juice, and Grand Marnier.
- antognini 9y agoThis is outside my area of expertise, but it seems that the author may not have presented Medawar's argument correctly. As I understand it, Medawar's theory of aging was not so much based in physics as based in evolution. The author presents it here as random DNA transcription errors building up mutations which eventually cause the animal to die. But I think that Medawar's argument was that all animals are subject to random accidents, predation, disease, etc. This will produce an exponential distribution of lifetimes. As a consequence, beyond a few half-lifes, there will be exponentially few members of the species. So if there is some mutation in the DNA which causes the animal to die beyond that time, there will be so few members of the species around to exhibit it that there will be effectively no selection pressure to keep this mutation out of the population. As a consequence, even if you started out with a population that could in theory live forever, it will very quickly become riddled with mutations which start to kill the animals after a couple of half-lifes. From the outside, it would appear as though the animals were "programmed" to die at a certain time. George Williams presented a similar argument, but also claimed that some mutations can increase an animal's fitness early in life at the expense of decreased fitness much later in life. If the animal will likely have died of some accident by that time anyway, this trait effectively has no downside and will be selected for.
- csomar 9y agoMaybe infinite aging is not the solution here. The probability that you die from an accident or cancer when your age is infinite is 100%. Brain backup, and brain uploading into a new body is a perfect solution. It might be harder but it cuts through the issues of aging and accidents.
- HugThem 9y agoIt would be interesting to simulate a little world with species that evolve via genetic crossover. And let them have an aging gene that is just a number: The average lifespan. Wonder what evolution in the simulation would come up with as the best lifespan. Could be a fun weekend project.
- hans05 9y agoI think the main reason we haven't seen many life forms evolving long life spans is that the biological cause of aging may be closely tied to other important things. So it may be difficult to evolve long life without some other disadvantage like slower growth.
- markstos 9y agoBecause sometimes systems need a start-from-scratch rewrite to progress.
- civilian 9y agoWe don't violate the 2nd law of thermodynamics. We're still increasing entropy, but we're processing so much fuel that the equations are still balanced when we locally increase order. Comparing lifespan to the bonds of a molecule is also pretty cringey. :-/ Obligatory link to Aubrey de Grey: https://www.ted.com/talks/aubrey_de_grey_says_we_can_avoid_aging https://www.ted.com/talks/aubrey_de_grey_says_we_can_avoid_a...
- dang 9y agoDiscussed at the time: https://news.ycombinator.com/item?id=11684718 https://news.ycombinator.com/item?id=11684718
- peterjlee 9y agoOne thought I had was that species evolved to maximize the survival of the species, not the individual organism. Once an organism is too old to reproduce or contribute to the survival of the species, it's probably better to die than becoming a burden to the rest of the members of your species. It sounds cold hearted and brutal but that's just how nature works. Maybe it is possible for an individual organism to reproduce and live forever someday but that would be very hard to achieve and we're probably stuck in a local maxima.
- antognini 9y agoThat doesn't really answer the question, though, of why animals get too old to reproduce. Surely it would be evolutionarily advantageous for an animal to be able to reproduce for its entire life.
- wmnwmn 9y agoTotally wrong from the get go. Cells do not use thermal energy to "ratchet" order out of chaos. That would violate the 2nd law of thermodynamics. Cells create order by using energy from an already-ordered source, namely the food you eat. This source is in turn ordered ultimately by exploiting a very high temperature differential, namely between the sun and earth temperatures. Usable energy can be extracted from differentials; it cannot be extracted from a heat bath at one temperature. But since we do have the virtually unlimited energy from the sun, and some other sources, we can lower entropy in a fixed region as much as we like. There is no physics barrier to repairing every single atom of aging damage in a human body.
- User23 9y agoWe tend to think of parents having offspring, but in a very real sense offspring use their parents as an entropy dump. Feynman's Lectures on Computation are a great read that explores the physical limits of computation and information.
- fizixer 9y agoThis (headline) is the one of the most idiotic things I've ever read on HN, regardless of the content of the article.
- daemonk 9y agoThat's like saying: given a flowchart where A->B->C, A leads to C, not B.
- foo101 9y agoNote this relevant comment from the author of the article: 'My original title was: "Aging: where physics meets biology". Nautilus changed the title to the above more provocative version, which seemed to have worked - judging from the number of responses!' Comment URL: http://nautil.us/issue/36/aging/physics-makes-aging-inevitable-not-biology#comment-2682776102 http://nautil.us/issue/36/aging/physics-makes-aging-inevitab...
- tanilama 9y agoNautil.us seems to have a tendency to publish pesudo sciency article with grand claim and irrelevant random thoughts.