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What percentage of people are alive today?
- seanahrens 15y agoSuper fascinating. Definitely would never have guessed it was anywhere even close to 12%. Wow.
- Qz 15y agoI've always wondered this! I thought it was probably relatively high, but 12% is pretty insane.
- willwagner 15y agoI had heard it was over 50% which i found very hard to believe so the 12% number seems a lot more reasonable.
- aquarin 15y agoWhat 200,00 BC mean, 200,000 BC?
- dennisgorelik 15y agoThe author made that error 3 times (cut&pasted wrong chart).
- jonathanbgood 15y agoThanks for pointing it out - we fixed this to 200,000 B.C.
- nivertech 15y agoFunny, that they have a cloud in their logo.
- iskander 15y agoThey never say how they estimate births_t.
- jonathanbgood 15y agoWe use the world population and average life expectancy to calculate births in a year. To connect these point estimates at the varying times in history we use a bounded exponential growth model for births.
- iskander 15y agoI'm still not completely getting it. Let's say in some year there are a billion people alive and the average life expectancy is 50 years. How are these two pieces of information sufficient to determine how many children were born in that year?
- amalcon 15y agoYou also need the previous year's population. With population and life expectancy, you can approximate the per capita death rate, and then it's a straightforward linear equation.
- a-priori 15y agoWhat about infant mortality? If a million babies are born in the year 234BC, and die before 233BC rolls around, they won't be counted in the population for either year.
- iskander 15y agoThat's what I'm wondering about. The infant mortality rates in pre-industrial times were astoundingly high, but I don't see anything that tries to explicitly account for them. I guess they get rolled in with life expectancy (bringing the mean way down), but it would be nice to see an explicit formula for births_t.
- tel 15y agoAm I the only one absolutely terrified by that number? Malthus wasn't wrong in principle, just in timescale. It's clear that technologies have improved Earth's human carrying capacity, but I don't know any method to claim that an S-shaped curve isn't inevitable. It's sounds science fiction-ey, but I don't understand how you can see data like this and then defund NASA.
- btilly 15y agoYou are not alone. If you want to get more scared, read http://www.amazon.com/Collapse-Societies-Choose-Fail-Succeed/dp/0670033375 http://www.amazon.com/Collapse-Societies-Choose-Fail-Succeed.... Interestingly from the population statistics alone it is possible to make an argument about the total likely future number of humans that will live. There is debate about whether the reasoning is correct, but it is at least suggestive. See http://en.wikipedia.org/wiki/Doomsday_argument http://en.wikipedia.org/wiki/Doomsday_argument for more.
- michaelchisari 15y agoAnd maybe once you're done with that, you can read a rebuttal of sorts: http://www.amazon.com/Coming-Population-Crash-Planets-Surprising/dp/0807085839 http://www.amazon.com/Coming-Population-Crash-Planets-Surpri...
- btilly 15y agoI am familiar with the arguments suggesting that population growth is self-limiting. I am also aware that the spread of birth control is breeding people whose will fail to use it. They may be a small portion of the overall population, but any portion that is on an exponential curve when the rest are not is bound to eventually dominate the population. Malthus has been postponed for centuries. And may well be postponed for more centuries. But unless resources grow exponentially, Malthus eventually will have the last laugh.
- ellyagg 15y agoI don't think the Doomsday Argument is that interesting. It may be trivially true, but it doesn't tell us anything interesting or predictive. All it says is that the chronology of human existence is too complicated for us to calculate. That being the case, our working assumption can only be that we're at the midpoint of our species population line. But, keep in mind that this estimate is really, really horrible, it's only virtue being that it's better than all the others. If someone gave you a trick coin, and you didn't know which side was favored, you'd have to assume 50/50, even knowing that you were certainly wrong. Knowing that one side is weighted doesn't give you any interesting information for one toss. If you follow the arguments for and against the DA, it's clear this isn't about a well-defined statistical argument, but immediately devolves into qualitative arguments about our survivability. The optimists say, well, based on the average extinction rate it's extremely unlikely we'll die in <100 million years. The pessimists counter that we're creating technologies with extinction level capacities very rapidly. Either way, we don't have a way of gauging the predictive power of these claims. We can't run a controlled study of 100 human species spans. And that's fine, because we need to argue about and introspect on the longevity of species, but brainteasers like the DA don't further it in any meaningful way.
- astrodust 15y agoThis back-of-the-envelope calculation appears to be off by a factor of two, which isn't bad. http://en.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived http://en.wikipedia.org/wiki/World_population#Number_of_huma...
- robbles 15y agothis error is because of assumptions about the life expectancy, right?
- jonathanbgood 15y agoYes, their birth rate assumptions would only yield the population milestones they suggest if the life expectancy was significantly below the reported level.
- deleted 15y ago[deleted]
- riprock 15y agoi'm sure there is a more accurate prediction out there (explained in papers) by researchers who have spent way more time and effort into this subject. for us common folks, there's even a wikipedia answer: http://en.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived http://en.wikipedia.org/wiki/World_population#Number_of_huma...
- deleted 15y ago[deleted]
- georgieporgie 15y agoI thought that 'humans', as in, you would see one and say, "yeah, that weird looking guy over there," went back about 2.2 - 2.3 million years. http://en.wikipedia.org/wiki/Human_evolution http://en.wikipedia.org/wiki/Human_evolution Populations would have been small, but an extra 2.1 million years is a long time.
- ANH 15y agoThere have been catastrophic events in that time that some believe acted as population bottlenecks, in particular the Toba eruption 70,000 years ago: http://en.wikipedia.org/wiki/Lake_Toba http://en.wikipedia.org/wiki/Lake_Toba Of course, there is much debate about the effect this had. [edit] In a recent Seminar About Long Term Thinking, a biologist said that there is evidence the human population was reduced to a few thousand by the Toba event. That is the extent of my knowledge on the subject.
- b_emery 15y agoQuote from that link: "There is some evidence, based on mitochondrial DNA, that the human race may have passed through a genetic bottleneck around this time, reducing genetic diversity below what would be expected from the age of the species. According to the Toba catastrophe theory proposed by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign in 1998, human populations may have been reduced to only a few tens of thousands of individuals by the Toba eruption."
- scott_s 15y agoFrom that, The dominant view among scientists concerning the origin of anatomically modern humans is the "Out of Africa" or recent African origin hypothesis, which argues that Homo sapiens arose in Africa and migrated out of the continent around 50,000 to 100,000 years ago, replacing populations of Homo erectus in Asia and Homo neanderthalensis in Europe. Scientists supporting an alternative multiregional hypothesis argue that Homo sapiens evolved as geographically separate but interbreeding populations stemming from a worldwide migration of Homo erectus out of Africa nearly 2.5 million years ago. The difference is that the species that we call Homo sapiens - us - is on the order of 100,000 years old.
- petercooper 15y agoNot to detract from the insight but: Until very recently life expectancy at birth hovered between 20 and 35 years, but in the past century it has risen to 67 years Most of this increase has been due to a precipitous crash in infant mortality, rather than a soaring increase in the median life expectancy. For example, even in the 1500s it seems a well-to-do Englishman (who lived a somewhat more hazardous life medically than even today's poor) had an average life expectancy of 71 if he made it as far as 21: http://apps.business.ualberta.ca/rfield/lifeexpectancy.htm http://apps.business.ualberta.ca/rfield/lifeexpectancy.htm
- kalid 15y agoExactly. One of my pet peeves is the misconception that a life expectancy of 35 means a normal adult somehow drops dead at that age. (And leads to arguments like "Oh, don't eat a paleo diet, cavemen only lived to 35"). Socrates lived to 71 in ancient Greece. Yet you know him for being a philosopher, not for living 2.5x the average age (like living to 200 today -- you'd think that'd make a fuss).
- wulczer 15y agoAnd he died condemned to death and executed, too! So he could have lived happily for many more years.
- hugh3 15y agoXenophanes of Colophon supposedly lived to 95. Pyrrho of Ellis lived to 90, and Democritus to 109. On the other hand, Epimenedes is supposed to have lived to the age of 154 or 290 depending on whom you believe, so take these numbers with a grain of artery-clogging sodium chloride.
- wulczer 15y agoYeah, and Noah reportedly died at 950, so I'd definitely take these numbers with a drop of hemlock :)
- melling 15y agoNow if we could get every person educated and productive, we could solve tens of billions of problems. Unfortunately, most people are just trying to survive.
- Unseelie 15y agoWe'd also have to give them problems to solve outside of 'how do I raise my children' or 'feed myself' or 'entertain myself'...or is that what you meant by productive?
- wbhart 15y agoThis is an important computation. It's even scarier if you suppose that you are not in any way special. It is likely that you are not one of the first 5% of humans to ever live. Thus, given that such a great proportions of all humans who have every lived are alive now, the implication is that the human race hasn't got long to go even if the population remains constant! Or you could just assume you are special.
- jodrellblank 15y agoBy that calculation, no human should assume they are in the last 5% so the human race is immortal. It sounds like nonsense; the people actually in the first 1% are not more special than the people in the 43rd 1%, but you have to be somewhere in the distribution. No point is special in the sense that you have a stronger than usual reason to assume you aren't there and are more likely elsewhere.
- wbhart 15y agoNot really. You shouldn't assume you are in the last 5%. Statistically, by definition, it is most likely (though not certain) that you are not.
- jodrellblank 15y agoThat's the sort of analysis I'm questioning - it's also 95% likely that I'm not in the second-last 5%, and the same for the third-last 5% and for any 5% slice. How can we usefully reason anything from a start like that?
- Detect 15y agoThis is great info if there ever is a zombie apocalypse. Eight heads each people.
- jleyank 15y agoI'm pretty sure I'm alive today, although some may have their doubts on Moday morning...
- deleted 15y ago[deleted]
- ck2 15y agoIt's an ugly thought but I think more people than ever are trying to create a biological retirement plan - having multiple children to take care of them later on. Trying not to make a moral judgment call on that and hoping I am just being too cynical. But think about how many people you know with children and then count the number that have conscientiously chosen to have only one.
- lwat 15y agoWikipedia lists the total number of people to ever live at about 115 billion, which means 6% of all people are still alive today. 12% is too much.
- baddox 15y agoI've always wondered something about evolution (or rather, speciation): how many generations removed could an ancestor and descendant be and still be theoretically able to mate? I'm sure the ability to mate isn't exactly the definition of a "species," but it seems like a decent way to get a grip on the extremely gradual genetic changes predicted/described by evolution. This article made me ask the question: How would you be able to recognize the "first human"?
- astrodust 15y agoSince it's speculated that Neanderthals and early humans inter-bred, then it stands to reason the gap can be pretty far apart. There are exceptions like those with dogs where one dog may be physically too small or too large to breed with another. I'm kind of irritated that some claim species cannot be created when a chihuahua and a Newfoundlander could not possibly inter-breed. If dogs like that were stumbled upon in the wild they would obviously be classified as entirely different species.
- Confusion 15y agoI fail to understand why this is of interest. The number doesn't tell you anything. If only 600M people were alive to today, the number would be a factor of 10 smaller. So what? You can't distill any meaning from the number. It doesn't predict anything, doesn't spell out opportunities, doesn't explain anything. It's a synthetic numerical fact, as constructed and unrelated to anything Real as the fact that the length of my thumb is exactly 1.5% of the height of the Eiffel tower.