8 ms·

Ask HN: What is the minimum number of people required to reboot civilization?

4 points by julienreszka 5y ago

SQL2219 5y ago
About an ark load.
detaro 5y ago
what do you mean by "reboot civilization"?
halfdaft 5y ago
assuming this is a simulation, then just one 'person' in base reality who knows computers
xupybd 5y ago
How long do you want the reboot to take?
_Microft 5y ago
The question might be too open-ended. Maybe some constraints might help with creating interesting discussion. How long ago did the old civilization go away? How many people are still around? Are there many remains of the old civilization? Did the former civilization prepare for this event and tried to leave seeds for a new civilization? If any, which ones?
gostsamo 5y ago
I understand it as reboot civilization after a disaster that kills everybody else and destroys all technology and collected knowledge. You need at least around a thousand people so that you avoid too close family relationships over the generations. Enough women to sustain birthrate over the 2.10 per woman number necessary for population stability. Even more births are necessary in a pre-modern society. At least 90% of your workforce will be involved in obtaining food. The number might be lower under favorable conditions, but have that in mind as a rule of thumb. If your seed population has access to large domesticated animals or source of fish, it will help them concentrate on the main job, a.k.a rebulding civilization. So, the rest of your population will be craftsmen, scientists, industry workers, and administrators that supposedly will facilitate the work of the others. Under administrators we can talk either bureaucrats or traders or whatever people you need for your distribution model. Craftsmen are people who build or obtain stuff that a single person cannot do on their own because it is time-consuming or requires specialized knowledge. This includes carpenters, smiths, farmacists, and so on. If we take ancient cities as an example of relatively independent units that are able to survive more or less on their own, and if we calculate the surrounding villages as food base for the city, with approximate population of a city around 4-5 thousand and 5-10 times more in the villages, the figure will be around 40000-50000 people. This culture must be well-organized, have written tradition, relatively free transfer of knowledge, stable environment, and space to expand. The future generations should be able to use the preserved knowledge for obtaining even more resources and have accelerated expansion. There is a tradeoff here, because the more knowledge you want preserved, the more people and resources should be involved in preserving it, which means more people needed to supply them with food, shelter, and parchment. So, try to keep only the knowledge necessary to build all the rest. Maybe good candidates are: math, logic, scientific method, mechanics, basic chemistry, biology, and astronomy (always good to know what part of the year it is if you want good agriculture). These are all back of the envelope thoughts so might not hold out under careful examination.
Renegado 5y ago
It depends on hundreds of factors, so, first let me outline the ideal ambient, that is: 1) Temperate climate, about 50'000 square kilometers surface, 1/2 good agricultural earth, 1/2 woodlands with good construction wood, lakes and rivers with clean water supply. 2) Non vaccinated survivors, no incest generated people with hereditary defects, mixed age sample, healthy, uniform race, IQ possibly the present mean European or higher. 3) Territory defensible by sea coast, large rivers, high mountains and/or deserts. No radioactive pollution. A group of islands may also fit the possible scenery. My estimation: basically we need six to ten million individuals and 200 years. P.S. for science fiction lovers: Antarctic would fit perfectly if the Earth axis shifts and the continent is placed in the temperate climate again but more time will be necessary to allow for the growth of forests first.
s1artibartfast 5y ago
Taking the question literally and ignoring environmental factors and other constraints, I would say the minimum answer is pretty simple: a reproductive pair of two humans. A lot is said about minimum viable population, genetic variability, and inbreeding but these are not absolute and insurmountable problems. You will have more or less challenges based on your two initial people, and it may not be possible with any two. Pre-screening of the individuals could rule out many of the nastiest recessive genetic diseases. An alternative and less savory solution is controlling for genetic disease with basic knowledge of Mendelian inheritance and eugenics. As a fun side note, the natives of the island Pingelap are an interesting example of a population that successfully rebuilt itself after a bottleneck of about 20 people. As a result, recessive color blindness is common, but their civilization was rebuilt. https://en.wikipedia.org/wiki/Pingelap#Total_color_blindness https://en.wikipedia.org/wiki/Pingelap#Total_color_blindness With respect to the time required to rebuild civilization, assuming no environmental constraints and the available knowledge for the past civilization, the primary limitation is the economic productivity of the population. If we ballpark the minimum population to produce modern technology at ~1 billion people, this would take 20 generations at 4 surviving children per woman. This is about 500 years at 25yrs per generation. This seems fast but might not be crazy if you compare it to the to the state of humans and medieval technology in 1500 AD, and the rate of development since then.
- Renegado 5y ago
  We are talking about science here, not about Biblical #fakenews. Inbreeding is as destructive as wars and atomic bombs. Adam (plural for "men"!) was created (cloning) in about 600 - 800 people, to avoid inbreeding. Other races (Adams returned to mate with "animals" according to Gilgamesh Epic) but GMO people without body hair survived. Recent theories suggest that Homo Sapiens Sapiens is in fact the GMO of Neanderthal People who, at some point, mate with the remaining pure Neanderthals. Mixed race (Neanderthal - GMO Adam) have little body hair and bigger penis than, say, Amerindians. Women's choice.
  - s1artibartfast 5y ago
    Im not sure what you are getting at here, or how it relates to what I posted.
lakotasapa 5y ago
Did you know every blueeyed individual can be traced back to a single couple in UK? >genetic mutation which took place 6-10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today Having said that, ideal would not so much how many people but how diverse of a gene pool can you get? Then add in human intervention ie. CRISPR if possible to then do gentle mutations to ensure the diversity keeps growing instead of shrinking once procreations starts.
PaulHoule 5y ago
From the viewpoint of genetics the usual guess is that you want 50 to 500 individuals to build a population. https://www.britannica.com/science/minimum-viable-population#ref1215147 https://www.britannica.com/science/minimum-viable-population... If people were attempting interplanetary/interstellar colonization or planning for a serious interruption they could possibly stockpile millions of human eggs.

4 points by julienreszka 5y ago

SQL2219 5y ago

About an ark load.

detaro 5y ago

what do you mean by "reboot civilization"?

halfdaft 5y ago

assuming this is a simulation, then just one 'person' in base reality who knows computers

xupybd 5y ago

How long do you want the reboot to take?

_Microft 5y ago

The question might be too open-ended. Maybe some constraints might help with creating interesting discussion. How long ago did the old civilization go away? How many people are still around? Are there many remains of the old civilization? Did the former civilization prepare for this event and tried to leave seeds for a new civilization? If any, which ones?

gostsamo 5y ago

I understand it as reboot civilization after a disaster that kills everybody else and destroys all technology and collected knowledge. You need at least around a thousand people so that you avoid too close family relationships over the generations. Enough women to sustain birthrate over the 2.10 per woman number necessary for population stability. Even more births are necessary in a pre-modern society. At least 90% of your workforce will be involved in obtaining food. The number might be lower under favorable conditions, but have that in mind as a rule of thumb. If your seed population has access to large domesticated animals or source of fish, it will help them concentrate on the main job, a.k.a rebulding civilization. So, the rest of your population will be craftsmen, scientists, industry workers, and administrators that supposedly will facilitate the work of the others. Under administrators we can talk either bureaucrats or traders or whatever people you need for your distribution model. Craftsmen are people who build or obtain stuff that a single person cannot do on their own because it is time-consuming or requires specialized knowledge. This includes carpenters, smiths, farmacists, and so on. If we take ancient cities as an example of relatively independent units that are able to survive more or less on their own, and if we calculate the surrounding villages as food base for the city, with approximate population of a city around 4-5 thousand and 5-10 times more in the villages, the figure will be around 40000-50000 people. This culture must be well-organized, have written tradition, relatively free transfer of knowledge, stable environment, and space to expand. The future generations should be able to use the preserved knowledge for obtaining even more resources and have accelerated expansion. There is a tradeoff here, because the more knowledge you want preserved, the more people and resources should be involved in preserving it, which means more people needed to supply them with food, shelter, and parchment. So, try to keep only the knowledge necessary to build all the rest. Maybe good candidates are: math, logic, scientific method, mechanics, basic chemistry, biology, and astronomy (always good to know what part of the year it is if you want good agriculture). These are all back of the envelope thoughts so might not hold out under careful examination.

Renegado 5y ago

It depends on hundreds of factors, so, first let me outline the ideal ambient, that is: 1) Temperate climate, about 50'000 square kilometers surface, 1/2 good agricultural earth, 1/2 woodlands with good construction wood, lakes and rivers with clean water supply. 2) Non vaccinated survivors, no incest generated people with hereditary defects, mixed age sample, healthy, uniform race, IQ possibly the present mean European or higher. 3) Territory defensible by sea coast, large rivers, high mountains and/or deserts. No radioactive pollution. A group of islands may also fit the possible scenery. My estimation: basically we need six to ten million individuals and 200 years. P.S. for science fiction lovers: Antarctic would fit perfectly if the Earth axis shifts and the continent is placed in the temperate climate again but more time will be necessary to allow for the growth of forests first.

s1artibartfast 5y ago

Taking the question literally and ignoring environmental factors and other constraints, I would say the minimum answer is pretty simple: a reproductive pair of two humans. A lot is said about minimum viable population, genetic variability, and inbreeding but these are not absolute and insurmountable problems. You will have more or less challenges based on your two initial people, and it may not be possible with any two. Pre-screening of the individuals could rule out many of the nastiest recessive genetic diseases. An alternative and less savory solution is controlling for genetic disease with basic knowledge of Mendelian inheritance and eugenics. As a fun side note, the natives of the island Pingelap are an interesting example of a population that successfully rebuilt itself after a bottleneck of about 20 people. As a result, recessive color blindness is common, but their civilization was rebuilt. https://en.wikipedia.org/wiki/Pingelap#Total_color_blindness https://en.wikipedia.org/wiki/Pingelap#Total_color_blindness With respect to the time required to rebuild civilization, assuming no environmental constraints and the available knowledge for the past civilization, the primary limitation is the economic productivity of the population. If we ballpark the minimum population to produce modern technology at ~1 billion people, this would take 20 generations at 4 surviving children per woman. This is about 500 years at 25yrs per generation. This seems fast but might not be crazy if you compare it to the to the state of humans and medieval technology in 1500 AD, and the rate of development since then.

Renegado 5y ago
We are talking about science here, not about Biblical #fakenews. Inbreeding is as destructive as wars and atomic bombs. Adam (plural for "men"!) was created (cloning) in about 600 - 800 people, to avoid inbreeding. Other races (Adams returned to mate with "animals" according to Gilgamesh Epic) but GMO people without body hair survived. Recent theories suggest that Homo Sapiens Sapiens is in fact the GMO of Neanderthal People who, at some point, mate with the remaining pure Neanderthals. Mixed race (Neanderthal - GMO Adam) have little body hair and bigger penis than, say, Amerindians. Women's choice.
- s1artibartfast 5y ago
  Im not sure what you are getting at here, or how it relates to what I posted.

lakotasapa 5y ago

Did you know every blueeyed individual can be traced back to a single couple in UK? >genetic mutation which took place 6-10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today Having said that, ideal would not so much how many people but how diverse of a gene pool can you get? Then add in human intervention ie. CRISPR if possible to then do gentle mutations to ensure the diversity keeps growing instead of shrinking once procreations starts.

PaulHoule 5y ago

From the viewpoint of genetics the usual guess is that you want 50 to 500 individuals to build a population. https://www.britannica.com/science/minimum-viable-population#ref1215147 https://www.britannica.com/science/minimum-viable-population... If people were attempting interplanetary/interstellar colonization or planning for a serious interruption they could possibly stockpile millions of human eggs.