
The Mythology of Dog Years - ryan_j_naughton
http://priceonomics.com/the-mythology-of-dog-years/
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simonsquiff
Can anyone explain why dogs (amongst others) age so much faster than humans? A
10 year old dog will be grey and have other visible aging signs, whilst we're
still youthful. What is the difference? Are dogs cells dividing at a faster
rate than ours, and if so why are they doing that? Presumably the answer gives
us insight into the aging process, but I've not been able to find answers in
some casual browsing.

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danieltillett
The why is easy - like everything it is because dogs that age any slower than
the average dog did not have any more offspring. The difficult question is the
how question - how do humans and dogs differ in their ageing process. Anyone
who can answer this will be more famous than Einstein.

A more interesting question is how do humans manage to age so much slower than
chimps. This has occurred so recently in evolutionary history that it must
involve only a few genes. Any process that is controlled by a few genes can,
in theory at least, be a pharmaceutical target.

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mrfusion
Are you sure humans age more slowly than chimps? I thought they basically live
to the same age?

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TomNomNom
The concept of 'dog years' has always interested me. I recently quipped to
some friends that if there's 7 dog years in a human year, there's 2^y computer
years in a human year; so a 6 year old computer is 64 in computer years.

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dvirsky
Oh man, that just made me realize my 9 year old dog doesn't have a lot of time
left probably. It's weird, she doesn't seem to behave any differently than say
4-5 years ago, and still has lots of energy and zero health issues. So I just
don't think of her as being old. According to these charts she's 55-60 in
human years.

~~~
electromagnetic
Depends on the dog, depends on the breed, depends on their health.

The problem with average life expectancy is that most dogs don't die of
natural causes, they get put down. We would have a shorter average life span
if we allowed people assisted suicide for those with terminal conditions,
especially ones that drag on for years or decades. Think ALS, Alzheimers and
Parkinson's, they can last twenty or thirty years. Often long past when a
person would want to die for the benefit of themselves but also everyone
around them.

We make that choice for our dogs. My in-laws put their dog down, he likely
could have got another year but he was suffering and you don't torture things
you love with forcing them to stay alive.

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jedberg
My vet actually had the 15, 10, 4, 4... etc chart on the wall.

I think 7 came because at the end of the dog's natural life you could get a
rough estimate using the rule of 7 because it averaged out.

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V-2
OK, a long read, but at the end it seems that she was actually even older than
the equivalent of 200 human years? :)

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dneronique
> Puberty range in most women and bitches

At first I was offended and then I was 'Oohh...'

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guard-of-terra
We humans are very badly designed.

A dog probably gets around eight active years or more, but we humans only have
like _three_. When we are mature, fertile, energetic, without building up
health problems.

And then we have six more dog years of being old.

~~~
Udo
Are you by chance in your early twenties?

The core message is that animal years map very badly to human years.

During the first twenty years, we are busy with development. The fertility
part is gender specific, and lasts about 25 to 30 years in women and much
longer in men. Conflating active years with fertility is a problematic idea.
Maturity is a very fuzzy concept, but cortical development is commonly not
considered complete until the mid-twenties. The variance in energy is probably
higher compared across different individuals than across different age groups.
Health problems also vary greatly from person to person, but it's fair to say
that crossing 40 risk factors for everything go up dramatically.

How many active years humans get out of their life is subject to great
individual variation. Some get zero. Others are highly productive for 60+
years. But I agree it's not enough - that's why we need transhuman advances in
science. Less than a Guard of Terra, maybe more like a Space Marine ;)

~~~
guard-of-terra
I'm in late twenties.

The idea that I have to make all the important choices in the first half
(second _quarter_ even) of my life which is almost over saddens me.

Short fertility in women (which we cut in half with our clumsy society) is THE
problem. With the exclusion of mismatches, which I shun, male fertility is
effectively limited to the same age range too.

~~~
Udo
It depends a lot on attitude. If you consider procreation and family a big
goal in your life, then you're right: the clock is always ticking. I'm almost
40 now, that ship has thoroughly sailed.

I don't agree that all the important choices happen during the first half
though. Consider that for the first 1.5 decades you hardly make any of your
own choices at all. So while the procreation thing is about halfway over at
your age, in a lot of other ways you're just getting started.

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guard-of-terra
If procreation and family is not a big goal in your life, then it ain't life.
Because reproduction is a defining property of "life" if you think of it.

As I've added, it's actually a quarter. For women in modern society it's even
less, close to 1/8 of their life.

After "the ship has sailed", no choices matter anymore. Surely, you may
decompose faster or slower, rot for quite some time or go out with the bang.
But it's confined to your own body now, which is definitely mortal.

~~~
Udo
_> If procreation and family is not a big goal in your life, then it ain't
life. [...] After "the ship has sailed", no choices matter anymore._

For your sake, I hope you'll change your view on this eventually. But I
appreciate your honesty in expressing your belief that I should just kill
myself right now.

It depends hugely on what value you assign to the human mind. If you believe
that humans are "just" wildlife and mere _existence_ is the highest achievable
goal, you're likely to come to the conclusion that nothing matters but
procreation.

But I highly doubt that you _really_ believe this, because you're here, on HN,
thinking about and debating matters that are far removed from the static
archaic society whose values you ostensibly subscribe to.

There are a lot of people who think that human life is more than a mere
bacteria-like existence, and that its value extends beyond our biological
goals and limitations. Whether you like it or not, we have long since started
to explore problem spaces that could simply never be addressed with mindless
biological evolution. For a few thousand years now we are in the process of
out-growing our original substrate. As a civilization we're engaged in a
complex struggle to eventually grow beyond an existence that is defined only
by the most basic biological needs.

If you can find it within yourself to identify with that struggle in some way,
you may find that defining procreation as the ultimate end-all-be-all was the
most bleak and unproductive premise you could possibly come up with.

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guard-of-terra
"your belief that I should just kill myself right now"

My belief is that you don't have do anything, because it doesn't matter
anymore. Might as well stay technically alive.

"For a few thousand years now we are in the process of out-growing our
original substrate"

We're still not there. If we had uterine replicators, the problem we're
discussing would be a non-issue.

But, we don't. So it's a huge issue. We have to stay alive, and we're all dead
in less than 100 years. Therefore, we have to reproduce. Surely we also have
other goals, but reproduction is a sanity check on those.

Maybe we can tear this chain apart one day, but we didn't yet.

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Udo
_> If we had uterine replicators, the problem we're discussing would be a non-
issue. But, we don't. So it's a huge issue. We have to stay alive, and we're
all dead in less than 100 years_

How can you look at this world and come to the conclusion that it's essential
- and indeed the sole reason for being here - for _everyone_ to spawn
offspring? Is there an underpopulation problem I'm not aware of? Is the human
race in danger of dying out?

 _> My belief is that you don't have do anything, because it doesn't matter
anymore. Might as well stay technically alive._

In the light of your answer above I can't square this logically. You're
asserting that my life would suddenly become meaningful again if we had
"uterine replicators"?

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guard-of-terra
"Is there an underpopulation problem I'm not aware of?"

Actually there is. A lot of developed societies face shrinking population. And
the population of young people capable of spawning offspring will decrease
much faster.

And I'm not sure that undeveloped societies are capable of both "carrying the
flag" and not falling into the same trap. They don't have a good record if you
ask me.

"You're asserting that my life would suddenly become meaningful again if we
had "uterine replicators"?"

Yes, because now you (or I) have choice to procreate. You may for some reason
refuse to do it, but you can. Now, when you no longer have this choice, you're
a "human minus procreation" which is less than "human".

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Udo
_> Yes, because now you (or I) have choice to procreate._

This is bizarre, because we're talking about the same mind, doing the same
things for society (or not) - it's just that in one case testicles have a
function and in the other they don't. So depending on the overall state of
gonads in our civilization I'm worthless now - but if we didn't need gonads,
my mind would suddenly start having a value?

That is truly and epically twisted.

 _> Now, when you no longer have this choice, you're a "human minus
procreation" which is less than "human"._

Well, to be labeled subhuman by you in this context feels almost like a
compliment.

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guard-of-terra
I'm not saying that you're worthless. I'm just not sure you're alive by strict
standards. I'm not sure I will be - in fifteen years.

So now you think that I've "labeled" 1000 - 1 to be less than 1000? So much
for math.

~~~
dllthomas
Even without passing on your own genes directly, you can:

1) help make sure those copies of your genes in others survive (help out
relatives who did reproduce) - evolutionarily, this is equivalent to
reproducing, if slightly attenuated;

and 2) have a lasting memetic impact.

And that's if you're focused only on the long term, which you seem to be -
there's plenty more shorter term reasons to be alive.

~~~
JoeAltmaier
Just to chase down this train of thought a little more: there are lots of ways
to benefit your clan (and therefore some of your genes) without reproducing.
Look at bees and termites, where the vast majority of them never reproduce,
yet the queen is driven to produce them because they help the colony survive.
That's selection too.

Or how about a gene that drives non-reproductive young males to be restless,
jump on a horse and ride over the horizon on a whim. Sometimes they come back,
say "There's buffalo over there!" and the whole tribe benefits. That's
selected for too.

~~~
guard-of-terra
Sad thing is, I don't have a clan. I don't have a beehive, a community. So it
seems that the only way for me to "keep the money in the bank" is reproduce
physically.

That's why nuclear family is called nuclear. And today we often have
"subnuclear" people without any strong bonds.

If I had a kind of clan, the situatiou would be different.

~~~
dllthomas
So if we take as given that you're going to be focused on the evolutionary
component, if you can no longer reproduce then walk up your family tree until
you find your closest relative with progeny.

[http://en.wikipedia.org/wiki/Kin_selection#Hamilton.27s_rule](http://en.wikipedia.org/wiki/Kin_selection#Hamilton.27s_rule)

[http://en.wikipedia.org/wiki/Inclusive_fitness](http://en.wikipedia.org/wiki/Inclusive_fitness)

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guard-of-terra
I'm not a walking set of genes. I'm a human being.

What if I don't feel that my "closest relative with progeny" is in any way
related to me?

I don't care about inclusive fitness. Let the nature do that trick. I care
about reproducing something resembling of myself. If my nearest genetic
relatives don't resemble myself in any way, I don't care if they reproduce.

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dllthomas
_" I'm not a walking set of genes. I'm a human being."_

Certainly. But then I'd say that a huge portion of what makes you you is not
genetic at all, and like I said much earlier you can always pass on memes.

~~~
guard-of-terra
I can't reliably pass on memes because I don't have a clan. I'm a lone nation
of one (well, two, anyway), and this nation is going to disappear once we die.

I can give memes to other unrelated people but I don't know whether they use
those for good.

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dllthomas
You don't know that your children will "use those for good" either. Focus on
spreading memes that _promote_ doing good, however you define "doing good".

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guard-of-terra
I don't think that promoting doing good works. It seems that bad things are
much easier to promote these days. I don't believe in it anymore.

Children are safe bet in that regards (if you failed - means you just passed
your failureness to them, good)

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dllthomas
_" It seems that bad things are much easier to promote these days."_

I don't see why that doesn't mean you should work _harder_ at it. Maybe the
marginal benefit is minimal, but if the marginal benefit of everything else is
zero then it might still be the best option.

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guard-of-terra
It's humiliating trying to walk thru the wall by fruitlees effort.

