Asking this because none of the 38 year olds I know are taking any medications and they look really young
No. And to be honest, it’s kind of stretching the limit of the title of the community.
No.
People have lived into their 80s for millenia. Average lifespan used to be shorter because of the amount of infant mortality. That is, anyone who made it out of childhood was likely to make it at least to their 60s, barring things like war and plague.
The simpler explanation is that the study is cookydooks.
Poopypoops?
According to the article it’s not about life expectancy, but that the lifespan of 38 is hardcoded into our DNA/Telomeres
Unless I missed something, the word “telomere” doesn’t occur in the article or its source paper—rather, it discusses the rate of DNA methylation.
IMO, the key passage in the paper is this:
However, any genetic regulation for a species may potentially be a secondary factor as there may be other environmental selective pressures. This may be the case with species which have lifespans post reproductive age and therefore, there may be non-genetic factors that may be more predictive of their maximum lifespan.
I suspect that the methylation rate is actually tracking the end of the reproductive stage of the lifecycle, rather than the entire lifespan—it’s just that humans have an unusually long post-reproductive stage.
It’s saying 38 is the maximum lifespan of a human, determined by genetics, and the only reason we can live past 38 is due to unnatural interventions ie medicine
It’s saying 38 is the maximum lifespan predicted by their model—but it also says their model has an R2 of 0.76, meaning it only predicts about 76% of the variation in the actual measured values. And then they discuss other factors that could account for the remaining 24% of the variation, including post-reproductive-age lifespan.
I’m not sure what the difference between “lifespan” and “expectancy” is other than semantics, given the context of your questions. Regardless of what our DNA says, our life expectancy is typically in the 70s or 80s, and that hasn’t changed much throughout known human history, so it has nothing to do with modern technology.
Life expectancy can be affected by things like infant deaths, disease, etc.
lifespan is the age an animal is designed to live for. The study (which was published in Nature btw) implies that humans reaching past 38 is unnatural and only a result of luck and modern technology.
That paper is garbage, then. People have been regularly living past 38 for thousands upon thousands of years.
And there’s no “design” for biology.
Outliers exist
They are only outliers if you’re factoring in infant deaths, which you already said you weren’t.
Humans lived past 38 long before modern technology.
https://pmc.ncbi.nlm.nih.gov/articles/PMC2625386/
https://sc.edu/uofsc/posts/2022/08/conversation-old-age-is-not-a-modern-phenomenon.php
https://www.sapiens.org/archaeology/life-expectancy-measure-misperception/
Logically, average life expectancy cannot be higher than average lifespan. For that to be true would mean that more people who made it out of childhood lived past their expected lifespan than didn’t, which doesn’t make sense.
If the expected lifespan is 38, than the average life expectancy before medical science advanced to the point where we could extend it should be lower than 38, but we in fact know that more often than not if you made it out of childhood in the past your chances of making it to 50+ were good, barring disease, war or what have you.
Average lifespan used to be shorter because of the amount of infant mortality.
That is completely wrong.
Lifespan is NOT the same as life expectancy:https://my.clevelandclinic.org/health/articles/lifespan
Lifespan is the maximum length of time that a person can live
https://www.discovermagazine.com/what-was-the-life-expectancy-of-ancient-humans-44847
Other research reveals that the lifespan of Homo sapiens may have changed from the Middle Paleolithic to the later Upper Paleolithic, since the ratio of older to younger remains increases. The same research shows that starting about 30,000 years ago at the beginning of the Upper Paleolithic, the average lifespan began to push past 30 years.
So 30000 years ago 30 years was pretty much the maximum age a person could achieve. Life expectancy would probably have been more around 15.
Read my other comment, the study is probably pretty close to the truth.
https://lemmy.world/comment/19682894
It’s a myth that people didn’t used to live very long. Infant mortality rate brought the average way down. However, everyone in power was super young for a while after the Black Death for obvious reasons.
Not at all. Until roughly 150-200 years ago infant and childhood mortality was almost 50% worldwide, which of course massively brings down the average lifespan. If someone made it to 20, they would probably make it to 60 and have a good chance of seeing 70 or more.
I feel a lot of the mortalities after 20 are things like infections. You really don’t have to go too far out of your way to stub a toe and ends up with sepsis. Things we’ve dealt with really effectively after a cure is detected.
If by “modern” you mean anything developed in the last 10,000 years, then no. We know humans lived to roughly the same maximum ages back then as today.
If you extend that to 100,000 years, then…maybe? It’s hard to say but it’s plausible at least.
The fossil record is not so detailed. It’s hard to estimate the age of fossils, and it’s hard to draw far-reaching conclusions from the limited number of well-preserved fossils that have been discovered. Most research doesn’t say anything more than “adult” or “child”.
There are some techniques used to estimate more precise ages, and the estimates of the age at the time of death for fossils from the Upper Paleolithic period (12k-50k years ago) or older is rather young.
The Smithsonian Institution has this to say about “Nandy”, a Neanderthal fossil from around 40,000 years ago:
scientists estimate he lived until 35–45 years of age. He would have been considered old to another Neandertal, and he would probably not have been able to survive without the care of his social group.
It’s similar for early Homo Sapiens fossils. At the Dolní Věstonice site, there was a ceremonially buried woman who’s estimated to be in her 40s, from about 30,000 years ago. She is thought to be one of the elders.
I’m not aware of any others that are generally believed to have been much older than that. That doesn’t mean that humans couldn’t or didn’t survive for longer, but it was surely more rare. That doesn’t really support wild claims of what’s “hardcoded” or what a “natural” lifespan is. There were certainly more things that could kill you 50,000 years ago than there are today, and most of them have nothing to do with DNA and have little bearing on the maximum lifespan.
The article is written very strangely, to the point where I honestly don’t know what they’re trying to say. They keep referring to the “natural” lifespan but never explain what exactly they mean by that, then they slide right into talking about “maximum” lifespan.
If you ignore every time they say “maximum” and assume by “natural” they mean “general life expectancy of an adult human”, then it seems fair enough. But statements like “Neanderthals and Denisovans…had a maximum lifespan of 37.8 years” are utter bullshit. I honestly think they were trying to say something completely different, but then decided “maximum” sounded cooler. Probably because of the X.
Asking this because none of the 38 year olds I know are taking any medications and they look really young
The basis of science is making your own observations and drawing your own conclusions. You’ve done the first half, now on to the 2nd.
Why ask if you’re not willing to consider answers that don’t agree with your source?
Most people in the world do not have adequate healthcare, many never seeing a doctor in their lives. Plenty of those live to much older than 38.
I’d say it’s very simple to see that whatever you found there is either misrepresenting majorly or complete bollocks.
It’s because the 38 years as average lifespan is skewed by high child mortality. People lived about 70 or 80 years – provided they first made it alive through childhood.
No. People even in the beginning of civilization lived for much longer than 38 years.
No
Hey why are you censoring actual military information and coherent information?
Nobody dies “naturally” of old age at 38.
But genetically we come from nomadic tribes, and the nomads of a 100000 years ago, had a far shorter average lifespan than after we settled and began farming. Also people of nomadic tribes in the rain forests of South America today, often don’t live longer than that on average AFAIK.When we look at animals, it is also not uncommon that a tamed animal pet can live twice as long or more than they usually do in the wild. For humans if modern environment has similar impact compared to the harsh life as a nomadic people, the double of 38 is 76 years, and that’s pretty close to life expectancy today.
So I certainly wouldn’t dismiss the claim outright, but the article is a bit thin on details on the science.
But it’s not just medicine (as speculated by OP), it’s also hygiene, food safety and work safety, so we avoid many external factors often until our body is simply too week to continue. We basically all reach an age where we are definitely ageing, and are very far from peak condition. Strength, speed and agility wise, very few sportspeople can compete over 40 years of age, despite the advantage of experience and more years of training.
But genetically we come from nomadic tribes, and AFAIK the nomads of a 100000 years ago, had a far shorter average lifespan than after we settled and began farming.
This is mainly because of child mortality. When you get five children, of which two live to be 78 and 89 and the other three die at ages of 2, 14, and 8, your children’s average lifespan is 38,2 years. Typically, you either died very young, or you lived old. And the average is, well, the average of those. Basically nobody died around the age of 38.
Tribal nomads of 100000 years ago did not live anywhere near to their 60’s.
AFAIK they rarely lived beyond 30.https://www.discovermagazine.com/what-was-the-life-expectancy-of-ancient-humans-44847
Other research reveals that the lifespan of Homo sapiens may have changed from the Middle Paleolithic to the later Upper Paleolithic, since the ratio of older to younger remains increases. The same research shows that starting about 30,000 years ago at the beginning of the Upper Paleolithic, the average lifespan began to push past 30 years.
Note that Lifespan is not the same as life expectancy:
https://my.clevelandclinic.org/health/articles/lifespan
Lifespan is the maximum length of time that a person can live
So 30000 years ago 30 years was pretty much the maximum age a person could achieve.
Life expectancy would probably have been around 15.Note that Lifespan is not the same as life expectancy
In this article it is, though. That’s why they use the phrase “average lifespan”. There is no “average” in maximum.
In the article the phrase “average lifespan” is used in the meaning “average life expectancy”.That still doesn’t mean 30 was the maximum possible age for humans 30,000 years ago. The ratio of older to younger remains doesn’t mean a whole lot unless you can prove death from old age.
It’s not like we have a plethora of remains to draw these conclusions from.
That still doesn’t mean 30 was the maximum possible age for humans 30,000 years ago.
Yes actually it does, above 30 would be an outlier.
Of course genetically they had about the same potential as modern people, but life was simply too harsh for people to survive above 30. The struggle to survive meant they were simply worn out at that point.
We see this even today in nomadic tribes in the rain forest of South America.
