How many humans make many humans?

I've been fantasizing a lot lately, actually for quite a while now, about the technical requirements for sending a manned mission to an alien solar system for recolonization and obviously one of the more complex things about space travel is the transportation of humans.

If however we could build a craft that could succesfully take humans to another star over the course of, say, 200 years or whatever, what would be required to restart a brand new human population?

Specifically, what would be required from a genetic perspective to ensure enough variation in descendents to prevent in-breeding and hill-billy style retardation and thus extinction. How many humans are required and in what gender proportion to be able to set off an entirely new population?

This scenario is of course not isolated to planetary colonization, but also to post-apocalyptic stlye repopulation.

reply to post by The_Modulus


Undoubtedly, this is something i have taken into consideration when rabidly oppressing the ideal of population control.

If you want the specifics, 200 years will probably be too short of a time, it would probably take well over 500.

As such, we are no longer talking about colonising alien solar systems, but now we are talking about colonising space itself.

From a genetic perspective, one would need a cross-section of society, black, white, asian, etc - having enough variation in this regard should ensure that the genetic code flourishes as opposed to becoming stagnant with 'hill-billy style retardation'.

Importantly, the craft we put out there needs to have all the capabilities that we currently possess right here on earth - it'll need a hydroponic system to generate nutrients and water, a mining module with which to take in new materials for the creation of new technologies, and most of all - entertainment.

The ability to analyse and research anomalies will be important too - it's quite likely that our space-faring cousins will find things out there in the depths of space which have never previously been found on earth, or at the least has been found in crashed meteorites.

Nevertheless, the ship will have to be big - far more massive than anything we have previously put in space.

It might even be worthwhile sending the materials into space and assembling them in orbit.

The important thing is this; sooner or later, it has to be done.

Good idea regarding racial variety. One would definately need a broad genetic variaqtion to ensure adaptation to as many environmental factors as possible.

But what is the absolute minimum number of people required to succesfully repopulate the species without running into family-breeding retardation?

There's some sci-fi movie from the 70's (or it may have been some anime series) in which this spaceship is filled with women and one man for repopulation. This surely wouldn't work out so well, unless I'm that guy hehe.

reply to post by The_Modulus


There's been dozens of variations on that idea, modulus, and not all of them are from the 70's.

But if you want my opinion on how many people we should put in the aforesaid gigantic space craft, i'd say the more people the better.

Naturally, i was working it out in such a way that the craft would be able to support a very large number of life-forms.

I might as well just call it a mothership, might'nt I?

If you're looking at what it would take to send people to another planet as a colony and eventually have it end up like here on Earth then you definitely would need a lot... I'd say on order of a few thousand at least.

This article here talks about our past population bottlenecks and genetic diversity and all that jazz. It kinda made my head hurt a little bit with all the scientific big words though. But it might help make some things clearer to make a more educated guess on a size required.

Though with what was said earlier, I wonder what it would take to have a couple old aircraft carriers or something cut up, gutted, tossed into orbit, reassembled and completely refitted to be space worthy as a starting point... I had a funny idea once about doing that with a submarine... ah well.

I think i read somewhere that the bare minimum needed is 100 people for the variation and non-inter breeding.

reply to post by Shaker


Mate, we don't even have to do that really.

What we really need is a smelting facility in space, something that can refine the ore we get from the rocks on earth.

That way, we could save a lot of worry about using existing materials to pull this little venture off.

We could also use that opportunity to take a few million pounds of rock from the asteroid belt, or even from saturn's ring system.

The important thing is to analyse the possibilities, and how we can give ourselves more options once we get up there.

It may well be the case we need to industrialise this particular solar system before we even dream of migrating to another.

So then, how can we go about getting humanity to buck itself up and meet the ultimate challenge?

The awnser to that would be

2

The awnser to that would be

2

I don't think the number is as important as controlling who 'mates' with who. A way of controlling it would be to introduce new surnames and if you were going to have sex with someone, it would only be permitted after a legal partnership. That way as long as you didn't sleep with someone with the same last name you would be safe. Hmmm kinda brings a reason for the 'no sex before mariage' belief! I think 100-200 split 50/50 male/female people would probably be enough to have enough variation to be selective about who you sleep with. The population would need to be fairly young as well so that the second generation would be born through natural selection and not forced 'survival sex'.

Originally posted by mopusvindictus
The awnser to that would be

2

No ... because then who would their children reproduce with? Even with 4 it could be risky because what if all of the offspring were the same sex?

[edit on 11-7-2008 by fiftyfifty]

A breakthrough in genetics would be needed to solve birth defects and in-breeding problems with 2 - 100 colonists.
Large numbers of people from different races would be another way, this can actually strengthen the gene pool but I think you'd need more people for that, maybe 400+. A big ship too loaded to the brim with supplies and all the gear for setting up a new world. You'd need a fleet of ships!

I read a book once about genetics, ancient astronauts etc and the writer reckons that if you can modify a persons genes to an extent that they are 'pure' then brother-sister relations produce kids that are perfectly healthy. This is where a lot of the biblical stories of Adam and Eves relations and offspring having a basis in scientific fact/reality. So genetics may be key here.