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Naked Mole Rats Defy Mortality Mathematics (discovermagazine.com)
An anonymous reader shares a report: Naked mole rats are adorably ugly creatures that challenge what we think we know about aging. Naked mole rats can live to be 30 years old. Further, female mole rats show no signs of menopause, and remain highly fertile even into their final years of life. Neurogenesis in naked mole rats continues over two decades, and their hearts and bones don't seem to change significantly over time. They rarely get cancer. Hell, they can even live up to 18 minutes utterly deprived of oxygen.
[...] At Google's biotech company, Calico, in San Francisco, California, biologist Rochelle Buffenstein is looking to the naked survivors to unlock their secrets of aging. Buffenstein says naked mole rats violate to the Gompertz-Makeham law, and she has over 3,000 data points to back her conclusion. After reaching adulthood six months into their lives, a naked mole rat's mortality risk remained the same for the rest of its days her analysis revealed. Rather than grow exponentially, a naked mole rat's risk of death on any given day, no matter their point in life, hovered around 1 in 10,000. Surprisingly, their mortality risk even fell a little when they grew very old. In this sense, Buffenstein writes, naked mole rats have established themselves as "a non-aging mammal. This life-history trend is unprecedented for mammals," Buffenstein and colleagues wrote in a study published recently in the journal eLife.
[...] At Google's biotech company, Calico, in San Francisco, California, biologist Rochelle Buffenstein is looking to the naked survivors to unlock their secrets of aging. Buffenstein says naked mole rats violate to the Gompertz-Makeham law, and she has over 3,000 data points to back her conclusion. After reaching adulthood six months into their lives, a naked mole rat's mortality risk remained the same for the rest of its days her analysis revealed. Rather than grow exponentially, a naked mole rat's risk of death on any given day, no matter their point in life, hovered around 1 in 10,000. Surprisingly, their mortality risk even fell a little when they grew very old. In this sense, Buffenstein writes, naked mole rats have established themselves as "a non-aging mammal. This life-history trend is unprecedented for mammals," Buffenstein and colleagues wrote in a study published recently in the journal eLife.
Rodents don't usually even live one tenth that long. 30 years for a small mammal is an absurdly long time, and the fact the life span doesn't have the usual rough correlation to body mass and metabolic rate in this case would be the equivalent of humans living 1,000 years. You'd better believe this is a hat trick worth learning.
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, but like extending strategies which reduce chances for procreation tend to be selected against...naturally.
Unless you take the path many insects do, where most individuals aren't involved in procreation: there's just a queen, and a few males kept around for the purpose. Bizarrely, this is how naked mole rates work - they have an insect hive, complete with drones and massive queen.
Socialism: a lie told by totalitarians and believed by fools.
For the high UIDs in the room, GPP was quoting a Kansas song:
Now, don't hang on, nothing lasts forever but the earth and sky
It slips away
And all your money won't another minute buy
Dust in the wind
All we are is dust in the wind
It's more of a philosophical statement than a practical one: entropy is going to win in the end.
Socialism: a lie told by totalitarians and believed by fools.
Having enough space is not the problem - the problem is having too much space, so that the finite amount of mass-energy in the universe gets spread too thin to support complex structures.
Also, if you have black holes then heat-death hasn't struck yet - they're still complex structure. But don't worry, they'll evaporate eventually, and then, when the last black holes have evaporated, heat-death will finally be complete.
And then, eventually, maybe, just the right quantum wrinkle will appear to spawn another big bang and spontaneously repopulate the universe - opinions vary on that question.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
No, absolutely not a bathtub curve.
A bathtub curve gives you a high probability of failing early on (manufacturing defects, etc), then a long period of relatively low, constant odds of failure, and then a climb back to a high probability of failure as things wear out. So that if you graph the odds of failure you get a U shape, or "bathtub cross-section"
They're claiming mole rats never get that final climb - in fact as they get really old the odds of dying actually *diminish*. That means that the older a mole rat gets, the better its odds are of still being alive in 10 years time.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
According to the article - exactly. That what makes them so incredibly interesting. Not just that they live an extremely long time for their size, but that their mortality curve is completely unlike any other animal we know of. Their mortality curve is flat at a constant ~1/10,000 per day, regardless of how old they get, and actually falls slightly as they get older.
They "live to thirty" not because they get old and die around age thirty, but because most of them die at a much younger age so things average out to a 30 year "expected lifespan". At those odds, the "halflife" of a mole rat is 6931.125 days: (1-1/10,000)^6931 = ~50% chance of not having died. So, they have a 50% chance of living to see 19, and if they make it, they have a 50% chance of living to see 38. And if they make it to 38, they would have a 50% chance of making it to 57 - assuming age based mortality doesn't start to show its head by then. As they mention in the article, perhaps age-based mortality starts making itself felt eventually, but their oldest individual made it to 35 and they're not seeing any evidence of an age-based increase in mortality yet.
If they make it to 29 then they've got a better-than average chance of making it through the next 10 years as well, but they only have a 35% chance of making it to 29 in the first place.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Humans can live to 80. That doesn't mean they all die by then, just that that's how long you expect a human to last on a good run. The article even mentions that the oldest rat in their lab is now 35.
With a 1/10,000 daily chance of mortality, mole rats have a half-life of ~19 years. Which means that the average lifespan of a molerat = 1.44*19y = 27.4 years.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Once it was clear that Jobs had the rare islet-cell pancreatic cancer, there was an excellent chance of a cure. According to Cleveland Clinic gastroenterologist Maged Rizk, MD, there’s an overall 80% to 90% chance of 5-year survival. In the world of cancer survival, that’s a huge milestone.
https://blogs.webmd.com/breaki...