So biologists say there is a limit. But if you only look at the statistics from extreme examples of people over 105, mortality looks flat for a few years, so statisticians say we can live forever.
Is it just me, or is this just bad logic?
Is it just me, or is this just bad logic?
One of two things may be true:
1) As we age, mortality rate increases until certain
2) As we age, mortality rate increases, and then levels off at some point
The latter doesn't mean you'll live forever: you're still already rolling the dice at the highest handicap every year. But it does mean there's no fundamental age everyone MUST die by (aka "live forever", if you're one in a billion).
The more interesting differentiation between the two, and the reason biology is interested in the question, is as an answer to "If we want to maximally prolong life, what do we do?"
If the flattening risk (option 2) model is correct, then we could extend life very far indeed by simply preventing people from dying of things that normally kill them by age 85 (e.g. disease, cancer) and then provide them with high quality medical support (to best fight the risk of their expiring from "normal" causes, e.g. accidents).
On the other hand, if it's ever-increasing risk (option 1), we should instead spend our effort at untangling the microbiology mysteries at the root of aging, and see if we can instead re-engineer systems to not work the way they currently do.
Or as my father (PhD in pathology) quips on the whole matter, "At some point, old folks are past the point that all of things that normally kill people would have killed them. And by virtue of still being alive, it's probable they're more resistant. We say they've reached escape velocity."
The "mortality rate" increasing then flattening out is just this curve reaching its peak then declining. The math of this is easy enough to figure out so not sure why there is a mystery amongst biologists about it.
I guarantee that once you understand how universal and simple the phenomenon is that's going here on you will be stunned at the ridiculousness of this "lifespan controversy".
People have a 50% chance of dying each year over 105 translates to there is no limit to longevity?
Also, the critic in me makes me want to see the actual distribution because I would think there is a tail effect going on and a small group of people are just genetically living much longer.
That being said, it seems that reading just about an scientific study these days makes you wonder if those doing the publishing understand data analysis, statistics, etc. It seems that too often they find some date, retro-fit a conclusion, ignore the flaws and holes, but still publish because they know the "journalists" won't figure it out either.
And then science complains about the public not buying into ever word science mutters? I don't get it.
Death rates increase every year due to naturally occurring mechanisms in the body. Consider those mechanisms as a function with the body as a parameter and the output as a more aged body (or rather a body with higher probability of failure).
If the body reaches a point where the death rate ceases to increase year per year, it would suggest that those same naturally occuring mechanisms, thought of as a function, approaches some asymptote.
Note this doesn't necessarily mean you stop aging (in appearance), just that your body's rate of failure no longer increases. This suggests that if the reasons for failure can be treated properly, perhaps the body can remain in that equilibrium state indefinitely.
This study provides some preliminary evidence that such an asymptote may exist in the body's natural mechanisms. Both controversial and exciting. Worth exploring further.
Because there are essentially two things that kill you. Either you die of something you get, or you die because your body wears out (as others have pointed out, we know body systems wear and become less effective with aging).
Therefore, if mortality stops increasing with respect to age at a certain point, but we know the body is accumulating additional wear that makes it less resilient, there must also be a corresponding decrease in mortality risk with respect to random things killing you.
So essentially, if you're 100 already... you might have a statistically smaller risk to die from heart disease, cancer, etc than someone who is only 92.
Agreed. I assume older people are receiving higher levels of care, and therefore have a lower risk of dying from random things.
For example, someone age 100 has a small chance of falling and receiving a life threatening injury when they go to get a glass of water from the kitchen. Someone age 115 might have a smaller risk, because they're more likely to be in a wheelchair, and therefore will not stumble and fall. Do they need to change a light bulb? The 100 year old might try to stand on a chair and risk falling. The 115 year old will probably have full-time care, and push a button to alert someone else about the light bulb. Older people usually travel less often, so their chance of dying in a car crash starts to decrease. They're no longer diving with sharks, so shark attack deaths decrease. They're less likely to be outside in a thunderstorm, so lightning related deaths decrease.
Some of those examples are a little silly, but I think the idea is right. When you go from 100 to 115, you decrease your risk of dying from random things (usually because you're no longer doing those things), but you increase your risk of dying from age related factors. These two cancel each other out, and the chance of dying on any given year appears equal. This would mean the study is wrong, and there is a limit to longevity.
So sooner you start the "treatment" the better as it is more fun to stop aging around 30 than 70 (which currently is already a thing, people aging a lot better than their parents).
It just sounds dumb because it doesn't take into account any physical limitations that would make the curve reach zero.
Obviously, there are a lot of "ifs" here but the result seems interesting and suggestive.