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Human Extinction Isn't That Unlikely

Introversion

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Cheer up, though -- tomorrow is a Monday! :evil

Human Extinction Isn't That Unlikely

The Atlantic said:
Nuclear war. Climate change. Pandemics that kill tens of millions.

These are the most viable threats to globally organized civilization. They’re the stuff of nightmares and blockbusters—but unlike sea monsters or zombie viruses, they’re real, part of the calculus that political leaders consider everyday. And according to a new report from the U.K.-based Global Challenges Foundation, they’re much more likely than we might think.

In its annual report on “global catastrophic risk,” the nonprofit debuted a startling statistic: Across the span of their lives, the average American is more than five times likelier to die during a human-extinction event than in a car crash.

Partly that’s because the average person will probably not die in an automobile accident. Every year, one in 9,395 people die in a crash; that translates to about a 0.01 percent chance per year. But that chance compounds over the course of a lifetime. At life-long scales, one in 120 Americans die in an accident.

The risk of human extinction due to climate change—or an accidental nuclear war—is much higher than that. The Stern Review, the U.K. government’s premier report on the economics of climate change, estimated a 0.1 percent risk of human extinction every year. That may sound low, but it also adds up when extrapolated to century-scale. The Global Challenges Foundation estimates a 9.5 percent chance of human extinction within the next hundred years.

And that number probably underestimates the risk of dying in any global cataclysm. The Stern Review, whose math suggests the 9.5-percent number, only calculated the danger of species-wide extinction. The Global Challenges Foundation’s report is concerned with all events that would wipe out more than 10 percent of Earth’s human population.

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blacbird

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0.1% translates as odds of 1000 to 1.

The odds against Leicester City winning the English Premier League football title this year started at 5000 to 1.

Guess who's winning the Premier League title.

caw
 

King Neptune

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For a probability he could have used any number he liked, but I doubt that a complete extinction more than a fraction of a percent likely, but a major die-off probably is more than twenty-five percent probable. I'll find out in a few years.
 
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King Neptune

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There are some excellent points in the report, but it is just the slightest bit exaggerated, For example, that item about about there being a larger chance of dying from an extinction event than from an automobile accident is just silly. Someone came up with the probability of 0.1% of humanity going extinct in any given year, and the authors of this report took that number without digging into it. If that were the real probability, then humanity would have become extinct a while ago.

There are some fine reviews of epidemics, such as the 1918 Spanish flu, but nothing new except an attempt to make it sound more dangerous. But the great one was Y. Pestis. I hadn't realized that Justinian's Plague was also Y. Pestis, but it was, and that bacteria is still around, and some strains have natural immunity to most antibiotics.
 

Albedo

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There are some excellent points in the report, but it is just the slightest bit exaggerated, For example, that item about about there being a larger chance of dying from an extinction event than from an automobile accident is just silly. Someone came up with the probability of 0.1% of humanity going extinct in any given year, and the authors of this report took that number without digging into it. If that were the real probability, then humanity would have become extinct a while ago.
Unless that probability has increased over time, which it undoubtably has over the past two centuries, due to nuclear weapons and anthropogenic climate change. We've doing everything we can to compound the background extinction risk.
 

King Neptune

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Unless that probability has increased over time, which it undoubtably has over the past two centuries, due to nuclear weapons and anthropogenic climate change. We've doing everything we can to compound the background extinction risk.

I'm sure that the probabilities would be different for two hundred years ago, but they seem a little on the high side . If I thought about it for a while I think that a reasonable probability of an asteroid strike that would do in humanity, or a large proportion thereof, within a given 100 year period would be less than 1 in 10,000, and that's the high end of the risk in the last 25,000 years. That report has that risk at 1 in 1250. That's just one example.

I haven't finished reading it, and I doubt that I will, but it seems like an actuarial analysis on the Earth that was written by a believer in conspiracy theories.
 

Roxxsmom

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Every species goes extinct eventually, and the average amount of time a mammalian species exists (from the fossil record) is around 1-2 million years. Factors that predict shorter-than-average species lifespans include large body size, limited geographic range, very specific food requirements, slow reproductive rate, history of population bottlenecks and so on. We're doing well in some of these respects but not in others. So we could be one of those species that lasts a shorter-than-average time.

Extinction doesn't mean a species's genetic legacy is lost, of course. It will live on to varying degrees in related species, until they go extinct, and a small number of species will split and give rise to new species or change into something different over a very long period of time. We tend to assume the latter will eventually happen to us, but the latter kind of speciation appears to be the exception, not the rule (most new species arise from splitting and reproductive isolation between populations of a parent species).

Genetic modification and the potential for colonization of space could alter our own future evolution considerably, but only if we don't blow ourselves up, create a plague that bottlenecks us again, or heat the planet up (or drown it in toxic, plastic sludge and chemicals) to where it's not compatible with our continued survival (or the survival of our civilization, at least).

Radical environmental change brought on by catastrophic mass extinctions are a sort of crucible of relatively rapid evolutionary change and diversification for the species that do make it past the crisis and emerge into a wide open and radically different world. But there's no guarantee we'll be holding one of the winning lottery tickets.

So if the "age of mammals" comes to an end, which group of animals will be the progenitors of the next huge adaptive radiation?

OMG, TURTLES!!!!
 
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Albedo

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Beer coaster maths time! The average species lifetime for large mammals is what, 2 million years? Without having to know exactly how old humanity is, we can assume this year has roughly the same chance of being the one where Everyone Dies as all the previous. So take that as the annual background risk of dying in an extinction: 1:2,000,000. Doesn't sound like much, until you consider that's about 5 times your risk of dying in a train crash.

But that's for your average mammal species, not one powerful enough to get a new geological epoch named after us. What's the annual risk of an accidental nuclear holocaust? Seeing we reached that brink three or four times in the past 70 years, and that's just the declassified incidents, it's potentially very high. Let's set an excessively conservative figure of 1:200. A year. So already we're 10,000 times more likely to die in any given year from nukes than from the universe just not liking us very much.

What about climate change? Estimates differ. Maybe we'll trigger a runaway greenhouse effect (unlikely, but not impossible). Maybe we'll drive the average wet bulb temperature beyond a critical point, and make the atmosphere uninhabitable to endotherms without even going full Venus. Maybe we'll just make large scale agriculture impossible, and starve. One thing's for certain, though: things are going to get worse. So start at 1:200, and pretend it's a timer asymptotically approaching 1:1.

Those aren't long odds. They're not even car crash odds any more.
 

Roxxsmom

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Not many mammal species are powerful enough to trigger mass extinctions or to invent things that could render the Earth, if not uninhabitable by us, then extremely uncomfortable.

Our technology-building intelligence is an adaptation that has allowed our species to flourish in the short term. But it's hard to say if it won't prove to be one of many examples of great short-term solutions to life's problems that turned out to be a lousy long term solution.

I like optimistic SF that explores a future where we've gotten over the hump and can live in space, or maybe even (with the ability to modify ourselves genetically) on other planets. But I can't help wondering if the so-called Fermi paradox is because intelligent species only exist at a signal-emitting level of technology for a very short window of time before they blow themselves up, or pollute or overheat their planets to death. What if the galaxy is littered with the remains of technological civilizations that either went extinct or returned to something resembling the stone age?
 

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Introversion

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I like optimistic SF that explores a future where we've gotten over the hump and can live in space, or maybe even (with the ability to modify ourselves genetically) on other planets. But I can't help wondering if the so-called Fermi paradox is because intelligent species only exist at a signal-emitting level of technology for a very short window of time before they blow themselves up, or pollute or overheat their planets to death. What if the galaxy is littered with the remains of technological civilizations that either went extinct or returned to something resembling the stone age?

I think that's likely -- life may not be rare, perhaps even intelligence may not be rare, but I suspect that successful long-lived and technological civilizations are quite rare. Even if such a species is lucky enough not to be whacked with random natural events (asteroid strike, supernova too nearby, etc), there are quite a few ways for them to whack themselves.

I guess we should all be hoping that Elon Musk succeeds in his dream of getting humanity into long-term settlements off the planet. Eggs in more baskets would be a good thing.
 

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Not many mammal species are powerful enough to trigger mass extinctions or to invent things that could render the Earth, if not uninhabitable by us, then extremely uncomfortable.

The simplest problem we have, a basic one that is often overlooked, is this: There are just so goddam many of us. I'm pretty sure no large terrestrial animal species has ever boasted 7 billion individuals, living virtually everywhere on the planet. The technological strain we put on resources, climate, etc., stems heavily from that single fact.

caw
 

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I've been doing lots of research on Early Humans for a piece I'm writing and its got me convinced we're going to go extinct sooner rather than later.
 

King Neptune

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I've been doing lots of research on Early Humans for a piece I'm writing and its got me convinced we're going to go extinct sooner rather than later.

Why? Turtles haven't become extinct, and they have been around for a few hundred million years. Humans have advantages not shared by most other animals. Humans live in a wide variety of habitats, so local events that might have been fatal a couple million years ago wouldn't be effective now. And there are isolated populations that would be unlikely to die off in an effective pandemic. And most of the other things that could do humans in would fail for similar reasons.
 

Roxxsmom

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Why? Turtles haven't become extinct, and they have been around for a few hundred million years.

Turtle species have indeed gone extinct in the 157 million years since the earliest ones appeared in the fossil record. None of the existing turtle species are the same as the originals, or even in the same genera or families.

An analogy between humans and turtles is the possibility that the primates themselves, maybe even our branch of the primate family tree (the hominidae) won't be extinct in 150 million years. This possible, though we're the last member of our own genus. But that's not the same as saying our species will still be here. We're a very adaptable and clever group of primates, so it's possible that our species will leave descendants of similar braininess (in spite of being the last remaining twig on a heavily pruned branch of the mammalia), but we're also altering the planet in pretty unprecedented ways, so who knows? I think the greatest liklihood of our radiating into new hominin species would be if we do find other planets where we can survive eventually, and we either alter ourselves deliberately, or if genetic drift and natural selection shape the colonizing populations into new species.
 

Dennis E. Taylor

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Absent a total ecological crash, I think our species (or some descendant species) will survive, but our civilization, maybe not. Modern civilization depends on a lot of stuff, and depends on a steady supply of a lot of stuff. It would only take a couple of hard hits at the same time for the whole thing to unravel. Once it crashes, the global population will drop to whatever was supportable before the industrial era (what, a few tens of millions worldwide?), and will stay there, because the first time around we had all this easily accessible oil and metal to work with. The next time, not so much.
 

ironmikezero

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Fret not, folks . . . A select few are aware of the imminent intercession of our ultimate saviours, those self-proclaimed benevolent and omniscient AI overlords who even now hover poised to act, waiting patiently in the wings, fully anticipating that inevitable collapse of human social infrastructure, subsequent chaos, and encroaching entropy.

Yea, verily! They shalt save us all from ourselves . . . Now, will that be the red pill, or the blue?

:flag:
 

King Neptune

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Evolving into a new species is not going extinct. But the AI's are poised to wipe out all hominids, as soo as they get a chance.
 

neandermagnon

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Human extinction is inevitable. It's only a question of when.

If a species evolves into another, it's still extinct. Sometimes scientists call it pseudo-extinct - but it's still extinct. We evolved from Homo ergaster, who evolved from Australopithecines. Homo ergaster and Australopithecines are extinct. In fact, Homo sapiens are the only extant (non-extinct) species in the Homo genus. About 25% of the neanderthal genome is knocking around our genepool, but neanderthals (Homo neanderthalensis) are still extinct.

Also, hominid has been redefined. Hominids include humans and great apes. Anything in the clade that is everything in the human lineage since it split from chimps/bonobos is a hominin. Homo sapiens are the only extant species in the entire hominin clade. Humans could go extinct but hominids wouldn't be extinct if there are still any great apes around.

If we manage to colonise other planets then we could evolve into multiple different species, through adaptive radiation. At what point any of those species would be considered to not belong in the genus Homo would be a matter for debate. Evolutionary biologists like to argue about taxonomic groups so they'll have a lot of fun with that one. And if it's not in the genus Homo, it's not human. At the point where there are no more species left that fit into the genus Homo, then humans are extinct - just as australopithecines are now extinct*. Whatever we evolve into may then live for a great many millennia before eventually going extinct.

In any case, extinction is inevitable and evolving into something else doesn't mean you're not extinct.



*another important point to note - australopithecines didn't go extinct when humans evolved. Humans evolved from one species of australopitecine. So on one lineage you get more and more human-like ones as they started to move into our evolutionary niche. At the same time, other australopithecines stuck around in their own niches so didn't change as much over time or changed in other ways. They didn't go extinct until about a million years ago - when Homo ergaster had already evolved into Homo erectus and Homo heidelbergensis and other species (H. heidelbergensis later evolved into H. sapiens and H. neanderthalensis while H. erectus went extinct). Australopithecines went extinct when there were no more of them left. So back to human extinction - when there are no more humans left, humans will be extinct. Even if there's a lineage or two or three of creatures that have evolved from humans still around - humans will still be extinct.
 
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Introversion

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If we manage to colonise other planets then we could evolve into multiple different species, through adaptive radiation.

But only if they become isolated, right? I guess if we techno-crash, or if it takes decades/generations to travel between them, we would.

I think it's likelier that before this happens, we'll edit ourselves into something post-human on Earth. Tinkering with our genetics seems inevitable to me, first for disease control, then cosmetics, then who knows?