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The Mathematics of the Lifespan of Species
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.'"
Keep my heart rate to a minimum...
“He’s not deformed, he’s just drunk!”
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.
...I should gain a couple hundred pounds?
Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
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.
Gently reply
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?
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How does one quantify the heartbeat of a daisy?
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That's ok, nobody did, because TFA is actually by an artist referencing that old paper, but he's really showing time lapses of dying plants. I been trolled.
All life was designed by God.
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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.
Computer modeling for biotech drug manufacturing is HARD!
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.
I stole this Sig
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.
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.
The counter is we wouldn't be here to ask the question in all the possible universes where we couldn't exist.
Another counter is that people shouldn't make up random bullshit theories and claim they're true just because they can't think of another explanation.
"Health nuts are going to feel stupid someday, lying in hospitals dying of nothing."
This issue is a bit more complicated than you think.
So, for your particular species, your best bet would be to select your parents for longevity. If you are into that sort of thing.
This issue is a bit more complicated than you think.
So pedometers should count backwards....
But I have a Unix heart; the counter flips over to zero in 2038.
Table-ized A.I.
Someone never heard of telomeres. Lobsters aren't very heavy but might be nearly immortal based upon their telomeres. Lobsters die from predation, not old age, 200+ year-old lobsters are documented. Telomeres are better than body mass for predicting average lifespan.
Everyone knows that the good are the first to go and parrots are minions of pure unadulterated evil.
Exactly, and if I recall correctly (from at least a decade ago, if not more), it does not apply to humans.
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)
licet differant, aequabitur
The furthest time that can be represented this way is 03:14:07 UTC on Tuesday, 19 January 2038.
You are being MICROattacked, from various angles, in a SOFT manner.
Exactly, and if I recall correctly (from at least a decade ago, if not more), it does not apply to humans.
Humans get old which is extremely unusual in nature.
"creatures as different as jellyfish and cheetahs, daisies and bats"
Daisies have heartbeats!
Bob.
It seems there's much more than humans that it doesn't apply to. Check out the plot of Mortality Rate to Mass at the end of the article. The "researchers" might see a linear relationship, but I certainly don't. There's so much variation that the statement that "size seems to predict lifespan" is only true in the most anecdotal sense.
Very poor article.
--
This was taught at Frances Slocum elementary school (Fort Wayne, IN, USA) circa 1968.
Verbum caro factum est
Apparently, scientists think that they don't die of old age.
I saw this first on a documentary, but here's a wikipedia article on it.
So, unless these guys are supposed to grow bigger-than-blue-whale big but they just do it super slowly, and these Anemone scientists were wrong about the 'forever' thing, but instead it's just 'a really, really long time', wouldn't this conflict with their theory?
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.
Just another day in Paradise
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. Think dogs and cats. Cats have anywhere from 2-4 kittens on average; dogs 6-10 puppies. Cats can live easily 20-30 years, dogs 10-20. Which one is bigger? Then again, wolves tend to have smaller litters and breed less often than dogs so maybe we tinkered with that.
So I guess my point is he has stumbled upon something (which may already be known according to other posters) but that it heavily overlaps with other theories. Now maybe size does play into r/K theory. From a high level view you have things like elephants, whales, humans and other large mammals that breed rarely and live long. Also I suppose its difficult to compare mammal verse reptile here. A tortoise lives a long time and lays many eggs but thats kind of how reptiles work. I don't know that it is a valid exception since it has reasons for not investing in raising children and to take a shot gun approach to it.
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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?
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 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 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.
A tree's heart beats really slowly though, so it makes sense.
http://buquad.com/2010/09/16/jellyfish-possess-eternal-life/
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?
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
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.
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.
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.
I thought this was a well known truth. As a kid we would guestimate the expected life expectancy of critter (species, not individual) by listening to how fast its heart beat. We would then confirm it later by checking the literature. You had to make an allowance for the fact that the critter was usually stressed and therefore the heart rate would be a bit higher than normal. I always just assumed that a muscle could only contract so many times before breaking down.
At least with regards to animals I believe this has been known for some time. In my early teens I attended a zoo camp. One day we discussed animal lifespans and the zoologist giving the lecture made a similar statement about all living species having roughly the same number of heartbeats in a lifetime. That was over 20 years ago.
A tree's what?
And red dwarfs have such long life spans that, if we're right about the age of the universe, none have died yet (of old age, anyway).
It would predict that the planet itself has no heart. It's life span is largely determined by the star it spins around. It'll probably be here until it is consumed when the sun turns into a red giant.
Trees work on the flow of water from the roots to the leaves through narrow tubes allow photosynthesis. There are different layers of food that have different functions. Basically the trunk of a tree is one giant artery. The inner core of the trunk, the heartwood is for strength, while it is the sapwood which transports water. The outer layer is for protection only.
Due to disease and old age, the sapwood will become damaged and no longer carry water.
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The outer layer transports sugars made from photosynthesis back down to the roots.
See this
The tree has no heart, the water is drawn up the tree by a process called transpiration.
Age doesn't really matter to water transport, since the cells that make up the tubes that carry water are dead.
FTFY
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