• Due to ongoing issues caused by Search, it has been temporarily disabled
  • Please excuse the mess, we're moving the furniture and restructuring the forum categories
  • You may need to edit your signatures.

    When we moved to Xenfora some of the signature options didn't come over. In the old software signatures were limited by a character limit, on Xenfora there are more options and there is a character number and number of lines limit. I've set maximum number of lines to 4 and unlimited characters.

All mammals have roughly the same number of heartbeats in a lifetime?

dogjones

Graduate Poster
Joined
Oct 3, 2005
Messages
1,303
This was a Trivial Pursuit question. According to this reputable source, all mammals have roughly the same number of heartbeats over the course of a lifetime, except humans which have more thanks to medical care.

Anything in it? A cursory google would indicate that this is certainly disputed.
 
If I recall correctly the life expectancy for an elephant is something like a humans (give or take a decade or two) and I'm sure I heard on a TV programme about elephants that their heart rate at rest is around half of that as a human so you'd expect elephants to live twice as long as a human!
 
Without really thinking about it, much less researching it, and just taking individual activity into account (e.g. my lean pet cat who is mostly feral and possibly suffering from the delusion that she is a tiger, spends ten hours a day terrorizing birds, squirrels, rabbits, and the occasional neighborhood dog that has escaped it's own yard and made the mistake of coming into mine; versus my mom's pet cat who is as wide as she is long and spends all of her time lounging in sun beams when she isn't busy eating fatty foods from a crystal platter) this claim would seem patently false.

However, if you are taking the average of all members of a species, and factoring in the sheer meaninglessness of the given term "roughly", Trivial Pursuit's legal team could probably pull it off.
 
It's not exact, but it seems fairly well established. This paper suggests a reason why. Basically, it's all down to the most basic functioning of cells, with the correlation between heart rate and lifetime simply being a consequence of how much energy cells need to live.

If I recall correctly the life expectancy for an elephant is something like a humans (give or take a decade or two) and I'm sure I heard on a TV programme about elephants that their heart rate at rest is around half of that as a human so you'd expect elephants to live twice as long as a human!

The important thing to remember is that this is science. "Roughly the same" doesn't mean actually the same, it's more like "within an order of magnitude or so". See this site for some examples (red table about 2/3 of the way down) and calculations. Having most animals with a factor of 3 or 4 is actually pretty close, even if it sounds a bit less impressive to the layperson.
 
Does it work as a predictor of life expectancy in humans, i.e. do those whose resting heart rate is a lot higher than the average of 60 tend to die correspondingly earlier than average?
 
Does it work as a predictor of life expectancy in humans, i.e. do those whose resting heart rate is a lot higher than the average of 60 tend to die correspondingly earlier than average?
Interesting question - and physically fitter people tend to have lower resting heart rates, but probably more than make up for it with the increased rate during exercise (do they?). Does someone who is very physically active over their lifetime, with a higher than average lifetime heart rate live a correspondingly shorter life than the couch potato with a relatively low lifetime average heart rate? I think not.
 
[snip versus my mom's pet cat who is as wide as she is long and spends all of her time lounging in sun beams when she isn't busy eating fatty foods from a crystal platter

Would your mom like another cat*?



*by cat, I mean a 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal**


**by 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal, I mean me.
 
I believe this notion was started by a calculation made by Isaac Asimov in one of his columns in Amazing, back in the 60s.
 
Would your mom like another cat*?



*by cat, I mean a 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal**


**by 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal, I mean me.
If you change to a puppy costume I might know a couple who'd take you. You are fixed, aren't you?
 
Would your mom like another cat*?



*by cat, I mean a 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal**


**by 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal, I mean me.

Wrong forum man.

ETA: I mean, cat.
 
Interesting question - and physically fitter people tend to have lower resting heart rates, but probably more than make up for it with the increased rate during exercise (do they?). Does someone who is very physically active over their lifetime, with a higher than average lifetime heart rate live a correspondingly shorter life than the couch potato with a relatively low lifetime average heart rate? I think not.

My reason for asking is that although I am reasonably fit and healthy my resting heart rate is usually between 80 and 90. I've never been sure if I should be concerned about that.
 
My reason for asking is that although I am reasonably fit and healthy my resting heart rate is usually between 80 and 90. I've never been sure if I should be concerned about that.

No not at all however please do check this site but don't wait too long.
 
This data suggests it is a myth based on some evidence of association, but not absolute correlation. See the table, "Lifetime Heartbeats and Animal Size", about halfway down the page. The data is graphed below the table. Lifetime heartbeats correlates with animal size, and size correlates with longevity, but it is not consistent and there are outliers just in this small sample.
 
This data suggests it is a myth based on some evidence of association, but not absolute correlation. See the table, "Lifetime Heartbeats and Animal Size", about halfway down the page. The data is graphed below the table. Lifetime heartbeats correlates with animal size, and size correlates with longevity, but it is not consistent and there are outliers just in this small sample.

Funny, I draw the exact opposite conclusions. As cuddles said, "Having most animals with a factor of 3 or 4 is actually pretty close, even if it sounds a bit less impressive to the layperson".

This not down to causation: number of heartbeats and lifespan are related for reasons other than the theoretical limit of heartbeats in a life. Rather, heart-rate is related to size, and size is related to lifespan.

You'll note that reptiles have a similar relationship, but it is different from that of mammals: ie. they have fewer heartbeats in their life. That's because they have a different sort of metabolism from mammals. But mammals whose metabolism has adapted in one direction or another will of course fall somewhere slightly off the theoretical line of this graph.
 
Would your mom like another cat*?



*by cat, I mean a 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal**


**by 47 year old human male in an adorably fluffy cat costume that likes having his belly rubbed and eating from fine crystal, I mean me.

I can ask her; but you should first know that she has all of her pets neutered...
 
Does it work as a predictor of life expectancy in humans, i.e. do those whose resting heart rate is a lot higher than the average of 60 tend to die correspondingly earlier than average?

According to the study I linked, no. The aim of the study was to find out if it might be possible to prolong life by reducing heart rate. The conclusion, as I noted above, is that heart rate is not the cause, both heart rate and lifespan are effects from an underlying cause, and simply manipulating one of those effects will not change the other.
 

Back
Top Bottom