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Science

The Mathematics of the Lifespan of Species 158

Posted by samzenpus
from the turn-out-the-lights dept.
skade88 writes "NPR is reporting on a study in which the author claims to have found the formula to predict the average life span of members of a species. It does not apply to specific individuals of that species, only to the average life span of members of the species as a whole. From the article: 'It's hard to believe that creatures as different as jellyfish and cheetahs, daisies and bats, are governed by the same mathematical logic, but size seems to predict lifespan. The formula seems to be nature's way to preserve larger creatures who need time to grow and prosper, and it not only operates in all living things, but even in the cells of living things. It tells animals for example, that there's a universal limit to life, that though they come in different sizes, they have roughly a billion and a half heart beats; elephant hearts beat slowly, hummingbird hearts beat fast, but when your count is up, you are over.'"
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The Mathematics of the Lifespan of Species

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  • by fustakrakich (1673220) on Thursday January 24, 2013 @12:23AM (#42677457) Journal

    Keep my heart rate to a minimum...

    • Ditto.

      But in all seriousness, even the summary says that this only applies to a species as a whole. Even if there was a hard quota on how many heartbeats you had, there's no point saving up your heartbeats not exercising just to die early from a heart attack.

      • But I am surprised the article does not mention even one of the obvious -- one might even say glaring -- exceptions.

        Take various species of tortoise for example. They can easily live to be 150 years old, yet weigh (many of them anyway) far less than a human. Same with many species of parrot.

        Then there's the hydra [wikipedia.org] ... 100 million years old or so, in its current form (just a wild guess... it could be a billion but I don't think that's likely), but every hydra is budded from its "parent"... so each indiv
      • by Spugglefink (1041680) on Thursday January 24, 2013 @07:33AM (#42678927)

        Even if there was a hard quota on how many heartbeats you had, there's no point saving up your heartbeats not exercising just to die early from a heart attack.

        Actually, I don't exercise for crap, I'm overweight, and my resting heart rate is riduclously high. Sure, exercise would get my heart rate up in the short term, but if I had a stronger, more athletic heart, built through exercising, I would conserve heartbeats over time. Mom was very athletic, and her resting heart rate was something scary slow.

        Of course Mom died when she was 55. Oops.

        • I've always exercised for short term well-being feeling and the fun of sport. As long as it doesnt seem to damage you in the long term (there are some open questions about this) or even lengthens you life, then all the better. I feel sorry for those slog through unpleasant exercise thinking they'll live a few years longer.
        • by mikael (484)

          You don't need to be sprint running or mountain climbed to keep fit. You just need to walk 30 minutes every day. Walking up and down staircases is even better. Avoid high-fructose corn syrup drinks and processed meat. Then the weight just melts off.

    • by haruchai (17472) on Thursday January 24, 2013 @01:08AM (#42677709)

      Funny but I don' t think the math adds up. Let's look at a 50 year period and assume a constant heart rate and skip pesky leap

      So for Joe Average, that's 26,280,000 minutes at 70 bpm or 1,839,600,000 beats.

      Now in that time Frankie Fitness works out 5 hrs per week for 50 yrs at a heart rate of 150 beats per minute so 780,000 min or 117,000,000 beats during exercise.

      Assume that drops his average heart rate to 60 bpm so over 50 years, the number of heartbeats outside when not exercising would be 60 * 25,500,000 = 1,530,000,000.
      So Frankie's total heartbeats over 50 years would be 1,647,000,000 so he saves close to 200 million beats over Joe Average.

    • by NotQuiteReal (608241) on Thursday January 24, 2013 @01:50AM (#42677909) Journal
      "Health nuts are going to feel stupid someday, lying in hospitals dying of nothing."
    • by PmanAce (1679902) on Thursday January 24, 2013 @02:58AM (#42678117) Homepage
      Wrong. By exercising one can lower their heart rate. Around 72 is generally considered the number of beats per minute. From daily exercise I lowered mine to low 50s bpm. What is the difference of the number of beats a year for example between both resting heart rates? Around 11 037 600 beats, looks quite staggering.
    • by Hentes (2461350)

      These formulas tend not to work for humans. We have a much longer lifespan than mammals of similar size.

      • by tlhIngan (30335)

        These formulas tend not to work for humans. We have a much longer lifespan than mammals of similar size.

        Humans are an exception because unlike most other species on earth, we use science to prolong lifespans. Modern medical science and other things have basically doubled our expected lifespans over 200 years (from around 40-ish in the 1800s to 80+ today). Even the lifespan in the 1900s generally haven't been all that much better over 1800. Though, kids born in the 21st century have a shorter expected lifesp

    • by Flammon (4726)

      You're resting HR is probably higher if you don't exercies. I would guess somewhere between 70 and 90 BPM depending on your body composition. I'll give you the benefit of the doubt and say that your resting HR is 70BPM. Which is about 100,800 beats per day.

      I exercise and because of that, my resting HR is between 45 and 55 BPM. If I exercise for 1 hour per day and my HR during that hour is about 140BPM, my total daily beats are 69,000 (23 hours) + 8,400 (1 hour) = 77,400 beats.

      Exercise and you're going to li

    • A very fit adult human will have a pulse rate of 50 or under, compared to the so-called medical average of 70. Say you triple your heart rate for one hour a day during vigorous exercise for the 25% reduction the other 23 hours. That is still a 13% pulse rate reduction over all.
  • This is not new (Score:5, Informative)

    by mbone (558574) on Thursday January 24, 2013 @12:24AM (#42677465)

    Isaac Asimov wrote an essay about this a long time ago (in the 1960's IIRC), and I doubt the idea originated with him.

    I believe Asimov was talking about 3 billion heartbeats or so as the limit; 1.5 billion heartbeats is only about 60 years for a human, and we tend to live longer than that under good conditions.

    • Re:This is not new (Score:4, Interesting)

      by Maxo-Texas (864189) on Thursday January 24, 2013 @12:41AM (#42677563)

      Aye... I remember reading that article. Perhaps in an Analog.. Perhaps in an IASFM.

      Amazing that these scientists are now "discovering" this "new" fact.

      Wonder how much knowledge we lose and have to rediscover.

    • Re:This is not new (Score:4, Insightful)

      by rnturn (11092) on Thursday January 24, 2013 @12:46AM (#42677579)

      Or correct.

      1.5 billion heartbeats for someone who has a constant heart rate of 72bpm would, according to this theory, only have them living for 39.6 years. So color me skeptical.

      And frankly, if my heart rate never deviated from 72bpm, I can't say I'd call that living. I'm still going out for a run tomorrow morning.

      • Re:This is not new (Score:5, Interesting)

        by retchdog (1319261) on Thursday January 24, 2013 @01:09AM (#42677719) Journal

        the summary says that the result is valid for species, not individuals. even that is wrong; it's not exactly valid for every species; the result is actually that there is a significant power-law trend across species which is that the mortality rate and birth rate both scale approximately as -0.25*(dry mass) on a log-log scale. however there is also significant variation from the log-log line-of-best-fit; the r^2 is around 0.8, though i don't care enough to read exactly how they designed the study. http://www.pnas.org/content/104/40/15777.full [pnas.org]

        humans have, of course, cheated death to some extent, so we're outliers, though it is worth noting that prehistoric humans had a max. lifespan of around 40 years...

        this is an old result for animal species; the `result' here is that they checked the extrapolated fit for ~700 plant species and validated it in that domain. scientists generally make small extensions or validate previous conjectures; since the public doesn't understand what they're building from, the media has to present the history as the novelty. it's kind of funny, really.

        i remember reading a paper (from sante fe institute, of course) ~20 years ago or so which tried to define a `generalized heartbeat' for cities and nation-states to see if the scaling law would extrapolate. of course, the problem is you can define such a thing however you want.

        • by kinnell (607819)

          humans have, of course, cheated death to some extent, so we're outliers, though it is worth noting that prehistoric humans had a max. lifespan of around 40 years...

          No. prehistoric humans had a life expectancy of 25-40 years [wikipedia.org]. Life expectancy is the mean age at death not the maximum lifespan. Given that we are genetically identical to prehistoric man, I think it's fair to say that they're maximum lifespan was somewhere between 100 and 120 years just like us.

          • by CastrTroy (595695)
            But then you can't really compare animals to humans at all. Medicine and nutrition has gotten so good that we have basically doubled our lifespan over our ancestors. You could probably compare humans to some domesticated animals, but even that's not a good comparison. If a dog get's cancer, most people wouldn't pay for chemo, and would just put the dog down, whereas for certain cancers, the survival rate is getting pretty high. Think about all the other medical procedures that would prolong your life af
          • by retchdog (1319261)

            pedantry. life span can refer to life expectancy, and that is what I meant. the point was just that animals don't have hospitals. if you take away the hospitals, humans fall in line with other animals.

          • My DNA is different to that of a homosapien 50,000 years ago.

            I'm of European decent, so I've got somewhere between 2 and 5% Neanderthals DNA.

        • by bcrowell (177657)

          however there is also significant variation from the log-log line-of-best-fit; the r^2 is around 0.8

          An R^2 value of 0.8 is actually pretty low. And looking at the graph, it's really only three points, even though it looks like a hundred points. They have one big blob for phytoplankton, one for trees, and a third blob in the middle for everything else. This is really not that impressive. If you throw three baseballs in a microwave and observe the resulting random positions, they will often come pretty close to lying on a single line (which is what the R^2 measures).

          Within each blob, the correlation looks l

          • by retchdog (1319261)

            yeah that's what I meant by significant variation.

            you're right about the effective sample size... I feel really stupid for missing it.

      • by dcw3 (649211)

        Take away healthcare, and everything humans have learned to extend their lives, then come back and tell us if you're still skeptical.

    • Re:This is not new (Score:4, Interesting)

      by Empiric (675968) on Thursday January 24, 2013 @12:49AM (#42677601)

      The 1960's was "a long time ago"? We have a much more accurate value than Asimov's in Genesis 6:3, applying to all the billions of human lives since, and verifiably correct to the two significant digits of precision indicated.

      In terms of specific methodology to arrive at that figure, though, I cannot say beyond the obvious. ;)

      • by tepples (727027) <tepples&gmail,com> on Thursday January 24, 2013 @11:19AM (#42680279) Homepage Journal

        We have a much more accurate value than Asimov's in Genesis 6:3

        "After that Jehovah said: 'My spirit shall not act toward man indefinitely in that he is also flesh. Accordingly his days shall amount to a hundred and twenty years.'" (Genesis 6:3, NWT) That verse could be referring to the fact that God was about to flood the inhabited parts of Earth 120 years later [answersingenesis.org] to wipe away the interference of the Nephilim, right after Lamech and Methuselah were about to die. Noah was born when Lamech was 182, Methuselah died when Lamech was 782, and Lamech died at 777. (Genesis 5:25-31) So both Methuselah and Lamech died fairly shortly before Noah turned 600 and the flood came. (Genesis 7:6) The parallel view of Genesis 6:3 [bible.cc] suggests that the authors of some paraphrase translations, such as the New Living Translation, didn't consider this possibility, even despite Abraham's over 170-year life.--Genesis 25:7.

        • by Empiric (675968)

          Understood that there are alternate interpretations. Depending on one's worldview, it does, however, pose something of a argumentative dilemma to invoke the bible as giving factual data points as one's only option in the process of denying it has a factual projection. For all the -verifiable- data points (such is googling "oldest living human") the prediction is spot-on.

          If we switch the context of discussion to a specifically theological context of the bible and the premise of accuracy, it is not difficul

        • by Reziac (43301) *

          One suspects a word meaning "moon months" got mistranslated as "years" somewhere along the line, since that would bring these elder folks down to a more typical human lifespan.

    • by wvmarle (1070040)

      This is not new indeed.

      And humans are a known exeption to this rule, living about twice as long as this formula would predict: at about 60 heartbeats per minute there are over 2.5 bln in the average life span of about 80 years for humans.

    • I think the new thing he has there is that he added plants to the equation. I don't know how he counts heartbeats for plants, but apparently they love us all.
    • by Khashishi (775369)

      The precise limit is 2147483647, because some lazy engineer decided that a 32 bit int counter was good enough. I plan on upgrading to the 64 bit heart. That will give me 9*10^18 or so heart beats before overflowing. Plenty enough for me.

  • ...I should gain a couple hundred pounds?

  • by retroworks (652802) on Thursday January 24, 2013 @12:29AM (#42677499) Homepage Journal
    Time passes faster when you're having fun. If we have a limited number of heartbeats, the trick is to stay as miserable as possible, so that the time will pass more slowly.
    • by alvinrod (889928)
      Should probably get high all of the time too, as apparently it makes time seem to pass more slowly. [youtube.com] Then again I don't know how miserable you can be when you're always stoned, so it probably offsets any gains.
    • If we have a limited number of heartbeats, the trick is to stay as miserable as possible, so that the time will pass more slowly.

      I knew pr0n would be the death of me!

    • by c0lo (1497653)
      True - I can imagine nothing more boring that to live on the Arctic ocean floor for 500+ [wikipedia.org] years.
    • That's not a viable strategy because your heart beat frequency also goes up if you are angry on something. Indeed, about every emotion increases it. What you therefore would need is an emotionless life.

    • by Grayhand (2610049)

      Time passes faster when you're having fun. If we have a limited number of heartbeats, the trick is to stay as miserable as possible, so that the time will pass more slowly.

      I think the old joke was if the doctor tells you that you have a year to live move to Montana and marry a Jewish girl. It'll seem like forever and you'll be glad be glad when you finally die.

  • by Irate Engineer (2814313) on Thursday January 24, 2013 @12:33AM (#42677513)
    He plots lifetime in days to entity mass in grams on a log-log plot and slaps a line on it. Note that some of the scatter in the vertical axis is up to 3 *orders of magnitude*. Had this been plotted on linear scale it would have looked like Jackson Pollock sneezed on the page. All that can be extracted is that big critters tend to live longer than small critters. So what is new here?
    • by Anonymous Coward

      Bingo! I kept thinking about the bristlecone pine & tortoises while reading this. Both huge exceptions to this sort of thinking.

  • How does one quantify the heartbeat of a daisy?
  • Just proves (Score:2, Funny)

    by zixxt (1547061)

    All life was designed by God.

  • I don't accept that we should see this as inevitable. We are learning a lot very rapidly about nanotech and biotech and some of those advances are in the fields of things like regeneration, cures, and life extension.

    I fully intend to work on developing this technology and trying to fix this problem. Just because our DNA is built this way doesn't mean that we can change it.

    Bioengineering and Nanoengineering are going to be some of the coolest things to do for a long time to come.

    • by c0lo (1497653)

      Just because our DNA is built this way doesn't mean that we can change it.

      Bioengineering and Nanoengineering are going to be some of the coolest things to do for a long time to come.

      True, brother, but not for you... not for you.

      It almost can feel some slightly trembling of your hands as you fingers miss some key while typing, a certain lack of attention and all that... signs of age catching up with you; you can no more change that DNA of yours, you simply don't have enough time to do significant discoveries... and posting on /. won't give you more of that precious time.

      • Just because GPP has a 5 digit ID number does not mean you have to be an asshole. FOAD.
      • You are guaranteed to lose if you don't try.

        Our cybernetics and regeneration are improving at insane rates.
        I am easily young enough to see these advancements extend my life in order to work on further advancements.

        Overall I would prefer to replace body parts with cybernetic parts than organic upgrades.

        • by tragedy (27079)

          But, if humans develop immortality, won't your people come along and blow up the ship we're carrying the secret (and the person who developed it) on? Then you'll just tell us: "You are not ready for immortality." Then I'll just have to say "Whatever. Anyway, we're going to order some pizza, but we all want different toppings. What do you want?" and you'll get all huffy and maybe violent and say "NEVER ASK THAT QUESTION!"

  • Relax (Score:4, Funny)

    by quantaman (517394) on Thursday January 24, 2013 @01:10AM (#42677725)

    That thumping sound you hear in your chest?

    That's your life beating away.

    If that sounds worrying you shouldn't worry, the worrying only just makes your heart beat faster and brings your inevitable demise that much closer.

    That worry is very dangerous, even if you stop now you've already shortened your lifespan, and for every second you worry longer you're losing more and more of your life. This worry and stress is literally killing you and it won't stop unless you stop getting stressed out.

    Just some friendly advice.

    • That thumping sound you hear in your chest?

      That's your life beating away.

      If that sounds worrying you shouldn't worry, the worrying only just makes your heart beat faster and brings your inevitable demise that much closer....

      Is your Heart attacking you? Well tell it to Beat It!
      Don't Despair, and Don't Delay!
      Get your AbioCor Pulse-less blood pump today!

      Our patented double helix flow system monitors and regulates your blood pressure smoothly, for all your oxygenation and cooling needs.
      Now your blood can course through your veins without the noisy and annoying pounding in your ears!
      Other implants have embarrassing charging wires, but you won't have a mess hanging out of your chest with our new wireless Transcutaneous Ene

    • recalls my Dad's advice to me...

      You'll die if you worry but you'll die if you don't - so why worry? enjoy yourself while you can

  • Exercise (Score:5, Informative)

    by eric31415927 (861917) on Thursday January 24, 2013 @01:43AM (#42677871)

    I came up with a similar theory years ago as an excuse not to exercise, for exercising increases one's heart rate. I concluded that exercise would therefore shorten my life. My girlfriend at the time didn't buy my logic. As a step aerobics instructor and science graduate student, she assured me that exercising only temporarily increases one's heart rate and that people who exercise regularly have slower heart rates during the non-exercising parts of their lives. I hate it when people use my own logic against me.

    • by eulernet (1132389)

      She is wrong.
      It's true that if you train your body to sustain strong effort, the every day life will require a lot less effort and your heart will require less effort.
      But aerobics is very bad for the heart, because if you have some hidden health problem, it will expose it.

      Yogis also believe that the human body has a limited number of heart-beats, so they try to slow down its beating.
      Their theory is that you can become immortal when you stop your heart (this is done by control of the breathing).
      I also heard

      • by tragedy (27079)

        Yogis also believe that the human body has a limited number of heart-beats

        I don't think Yogis _also_ believe that. I think Yogis believe that and the idea has gotten lodged into our cultural meme-trap and non-scientific "studies" like this one pop up every few years to try to "prove" it and get splashed around as pop-science. It's annoying because it's not really substantial enough to disprove. Our tissues wear out, the heart is made of tissues and it wears out. There's an approximate amount of time this takes, as well as an approximate amount of time we live and an approximate n

    • Yeah my resting heart rate is 45 beats per minute thanks to my love of running and some very good genes! At the computer right now it's reporting 50 on my iPhone, so it more likely hovers around that during the day.
  • Wrong wrong wrong (Score:5, Interesting)

    by EmperorOfCanada (1332175) on Thursday January 24, 2013 @01:43AM (#42677875)
    There are so many exceptions to this "rule" that it is at best an interesting pattern. There are big turtles that live great long lives and big turtles that don't with little turtles being all over the place as well. There are birds of all kinds of sizes with small birds that live 80 years and big birds that live under 20. Some bacteria seem to be nearly immortal and others live days. Within dogs the big ones hardly outlast green bananas while the little ratty ones go on for decades. Poplar trees grow huge and die fast, oaks go on and on but some smaller trees are thousands of years old.

    Even humming birds live a few years at crazy heartbeats as high as 1200 bpm (look it up if you don't buy that mind blowing number) yet other bigger birds with much slower heart beats live for the same length of time. So it isn't size or heartbeats.

    If I had to suspect anything lifespan will be an evolutionary advantage like anything else. If you are surrounded by ever changing dangers a short fast life-cycle is probably best. But if you are fairly safe in steady environment a long life is probably safer. Turtles have slow metabolisms which allow them to survive long periods without food and are fairly safe from predictors so they don't have to worry about adapting too much. Rabbits are basically the forest's McNuggets so they need to continuously adapt in numbers and probably other things such as coloring; hence a fast short life cycle. We have created civilization where we are nearly 100% safe from predators and with things like food storage are not so buffeted by a changing nature; so we are getting longer an longer lived.
    • by Baby Duck (176251)
      Koi fish are another counter-argument, even if they never freeze into suspended animation.
  • So, for your particular species, your best bet would be to select your parents for longevity. If you are into that sort of thing.
  • So pedometers should count backwards....
  • 2038 (Score:5, Funny)

    by Tablizer (95088) on Thursday January 24, 2013 @02:44AM (#42678073) Homepage Journal

    "roughly a billion and a half heart beats...when your count is up, you are over.'"

    But I have a Unix heart; the counter flips over to zero in 2038.

  • Parrots

    Galapagos Tortoises

    Dogs (small ones tend to outlive larger ones by a factor sometimes approaching 2)

    (and those are just the 1st 3 examples which spring to mind in 30 s)
  • "creatures as different as jellyfish and cheetahs, daisies and bats"

    Daisies have heartbeats!

    Bob.

  • What about all these politicians? Are we stuck with them forever?

    Before anyone goes off on left vs. right being more heartless...it's a joke, get over yourself.

  • It is an interesting concept however it does appear to have some easily named exceptions as others have pointed out. It also though has a lot of overlap with reproduction selectivity (r/K theory). Namely animals with shorter lifespans breed quicker and have more offspring than animals that live longer and have longer gestation periods.

    Think about it... you have an elephant which takes nearly 2 years to come to term, it would make no sense to have a 10 year life cycle. Instead, they can live 60-70 years. Thi

  • Explain to me the similar lifespans of gray parrots and elephants?

    What about snakes, and other reptiles that continue growing with age. Do they die younger when young, and live longer when old?

  • So I RTFA, which is mostly fluffy but has a graph and some links to the real research....BUT at the center of it is an assumption that goes unquestioned:

    So Geoffrey West and his colleagues found that nature gives larger creatures a gift: more efficient cells. Literally.

    Why not ask if the first step is when an organism hits upon a mutation to improve its efficiency and the consequence is larger/longer lasting individuals?

  • We dont live longer because we are larger, but are larger because we live longer. Both could be tied to a third factor such as inherent genetic metabolic rate.
  • who need time to grow and breed, successfully

    FTFY

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