Colonization Requires At Least 10,000 People

Humans may one day live on other worlds.

A new study has calculated how many people it would take to viably populate another planet.

In the future we may see generational ships heading out across the stars on voyages lasting thousands of years in the hopes of finding new Earth-like worlds to colonize.

Back in 2002, anthropologist John Moore calculated that such a ship would need at least 150 people in order to survive a 2,000-year trip across the cosmos, but is this really enough ? A more recent study conducted by Cameron Smith or Portland State University has cast doubt on this conclusion and suggests that a more realistic number to ensure survival would be between 10,000 and 40,000 people.

These figures were reached by taking in to account the necessary genetic diversity of a population, the possibility of disease or disaster along the way and the likely growth rate from natural births.

"I did this study to materially help in putting together the millions of puzzle pieces that will be required to allow humanity to spread out from our earthly cradle," he said.

Gardner-O'Kearny calculated each population's possible trajectory over 300 years, or 30 generations. Because there are a lot of random variables to consider, he calculated the trajectory of each population 10 times, then averaged the results. (With one exception: The starting population of 40,000 is so large that it takes 18 hours to complete each simulation, so he calculated that trajectory only once.)

Genetic diversity keeps groups healthy, and larger populations tend to have more diversity. In small or isolated groups, including Ashkenazi Jews and the Amish, marriage between relatives has reduced genetic diversity and made otherwise rare diseases such as Tay Sachs and cystic fibrosis common among those populations. Graph A shows that Moore's suggestion of 150 people is not nearly high enough to maintain genetic variation. Over many generations, inbreeding leads to the loss of more than 80 percent of the original diversity found within the hypothetical gene.

A population of 500 people would not be sufficient either, Smith says. "Five hundred people picked at random today from the human population would not probably represent all of human genetic diversity . . . If you're going to seed a planet for its entire future, you want to have as much genetic diversity as possible, because that diversity is your insurance policy for adaptation to new conditions."

A starting population of 40,000 people maintains 100 percent of its variation, while the 10,000-person scenario stays relatively stable too. So, Smith concludes that a number between 10,000 and 40,000 is a pretty safe bet when it comes to preserving genetic variation.

The second threat to interstellar voyagers is catastrophes—plague, war, collisions, and mechanical failures—that could wipe out large portions of the population at any time.

The population of 40,000 can take quite a hit but still manage to stay within the range of a healthy population size, and the 10,000-person starship survives pretty well too.

To check out the smaller populations, we need to zoom in:

When 10,000 people are housed in one starship, there's a potential for a giant catastrophe to wipe out almost everyone onboard. But when 10,000 people are spread out over five ships of 2000 apiece, the damage is limited.

To make interstellar travel a reality, scientists and engineers will have to overcome huge obstacles. They'll need to find ways to increase propulsion speed, prevent the negative health effects that arise from living in space, and devise self-sustaining systems that provide food, water, and air. At least the new calculations provide some sort of starting point.

"With 10,000," Smith says, "you can set off with good amount of human genetic diversity, survive even a bad disease sweep, and arrive in numbers, perhaps, and diversity sufficient to make a good go at Humanity 2.0."

Source: www.popularmechanics.com... 51924704

I thought this was so interesting. After reading this though my first question was. "Wait, how many people are we sending to Mars in 2025?"
The answer is 4.
And then send 4 more people, every 2 years.... They did say that in the future there might be a vehicle to carry more people at the same time, but still...???

Reading this,it seems they'd need to be careful, avoid getting sick, stay super healthy, until the next 4 people come along, and then more every two years, oh then they have to be diverse enough too.

I am still positive this can be done, and hope in the future they will be able to design bigger vehicles to transport more people, otherwise, that colony will take ages to build.

What are your thoughts dear ATS members?

hm... Why was I told 25 males and 25 females were needed to insure the survival of a specie?

That's a lot lot less than 10 000, or even 40 000 people!

The idea of sending multiple ships is indeed a better way to insure the arrival of as many people as possible. Until technology allows to send 40 000 without any major risks.

Well, I imagine four (4) and then 4 more every two (2) years after that for engaging in scientific exploration.
Initially at least for that matter.

I am pretty sure that once sufficient data has been gathered and the experiences recorded, it would tell if Mars would be a viable place to live and continue exploration, plus infrastructure has to be built.

We will see people go to mars in our lifetime, but colonization takes time, especially with our current technology, which is why I place heavy emphasis on the private sector leading the charge.

I am sure the rewards would be massive, but the cost could lead to almost certain death.

What I want to know is if people do start going, would it be some random joe? or a person with certain attributes and personalities? We are talking about a whole new society here.

Btw, S&F!!

reply to post by Arnie123


Thank you.


I don't want to rain on anyone's parade, but if this slow progress is the case, I truly believe we should be sending doctors and scientists first, to ensure that everyone stays fit and healthy, and everything human and technological can be monitored by professionals.

Just my humble two cents.

reply to post by Rainbowresidue


We could bring along enough genetic material in stasis to diversify the group upon arrival and confirmation of habitability.

That would allow us to lower costs per colonization mission and therefore create more and better chances for success.

I have an " obvious " idea for reducing the required number

step one - DNA screen all the potential qualified crew pool - and pick the take off crew crew of the maximum possible genetic diversity

step two - gender imbalance - the " take off crew " would be 95% female , 05% male

step three - carry genetically diverse frozen eggs and sperm in large quantities [ this is the rational for step two ]

step four - selective breeding program

obviously this would require a bit of fine tuning - but in theory you would have the potential to lauch a much smaller take off crew that had the capability to breed a genetically diverse end population

NowanKenubi
hm... Why was I told 25 males and 25 females were needed to insure the survival of a specie?

That's a lot lot less than 10 000, or even 40 000 people!

The idea of sending multiple ships is indeed a better way to insure the arrival of as many people as possible. Until technology allows to send 40 000 without any major risks.

The article isn't just talking the survivability of a colony but maintaining the genetic diversity of the colony.

While 25 males and 25 females would allow the survivalbility of species the genetic diversity of species can not be maintained. To maintain the genetic diversity a larger population is necessary that's what the article is refering to.

reply to post by ignorant_ape

--
That's a start right there.

Ill tell you what, I sure would like to be that .05%, lol

reply to post by ignorant_ape


Now that's a great idea!

reply to post by Arnie123


You'd be the luckiest man on Mars!!!!

reply to post by Rainbowresidue


One thing that wasn't taken into account is that by the time we're able to do this, the average person might live 150 years or more. Also, we might have some sort of stasis or cryo-sleep by then as well.

If we're ever at a point where we can get 10,000 people into space, let alone travel somewhere, we're going to be pretty advanced.

So on this 2 thousand year journey, the first generations will know their mission, in time others will believe their ship evolved naturally and there was no creator of "ship" that it formed naturally. They will scoff at ancient mission journals calling it brainwash material. In time the ships inhabitants will fight for their rights to deviate from their creators mission, demand same sex joy, live for oneself, strive for power and control. Establish hierarchies of thought, power and segregate the races.

Round and round we go.

A man is smart, people are stupid. - K

reply to post by Shadow Herder


Good point!

But can be avoided easily just by having 'History of Mankind' book available to them. Which I'm sure they will.

With the scientist they could also send a theology scholar up, to make sure we have their history/ evolution/ religion covered.

I'm sure they are thinking of all aspects of this scenario.

And of course the theology scholar would have to be expert in all religions,though sometimes I think... why not start fresh?

I'm pretty sure the human history part would be for them to read and available though. That's very important.

I'm not religious,so I was just thinking more about conserving our history and evolution.

Rainbowresidue
reply to post by Shadow Herder

 

Good point!

But can be avoided easily just by having 'History of Mankind' book available to them. Which I'm sure they will.

We can call it the bible. Lets hope dialect, writing and comprehension remains unchanged or the book will sound like unbelievable hogwash.

With the scientist they could also send a theology scholar up, to make sure we have their history/ evolution/ religion covered.

We can call these guys prophets, but many will stop believing their stories for they think it has no purpose in their lives for it was written too long ago to have any present purpose.

I'm pretty sure the human history part would be for them to read and available though. That's very important.

Do you consider the bible or other ancient lores as definitive history?

Well...

Thats sticking to todays societal and moral norms.


Could easily be accomplished with A.I.s and or a few people, and frozen egg and sperm in the very near future.

Send an A.I. or a sufficiently advanced drone that could be updated remotely...

You could compact a colony, I mean, why does it have to be people raised in our society that we send? Why not our DNA and Ideals.

Hell, You could send out ships to all the planets that have water we find, let them drift through space slowly, one day we can hope a complementary society sprung up from our attempts.

benrl
Well...

Thats sticking to todays societal and moral norms.


Could easily be accomplished with A.I.s and or a few people, and frozen egg and sperm in the very near future.

Send an A.I. or a sufficiently advanced drone that could be updated remotely...

\\

Maybe we arent meant to travel to faraway places just as cells that construct the flesh on your butt do not belong with the cells in your brain.

First thing they have to do is how to save human reproductive elements from
radiation bombarment once they leave the earth astromphere.

But, it that is possible you will have millions trying to get the hell of this planet and that would be there opportunity.

The Good, Bad and the Ugly would all be out.

Just a chance to get out from the thumb of danger from the less.... desired of our population.

You know the ones who are preditors and target humans.

Shadow Herder

benrl
Well...

Thats sticking to todays societal and moral norms.


Could easily be accomplished with A.I.s and or a few people, and frozen egg and sperm in the very near future.

Send an A.I. or a sufficiently advanced drone that could be updated remotely...

\\

Maybe we arent meant to travel to faraway places just as cells that construct the flesh on your butt do not belong with the cells in your brain.

We aren't designed for space, not by any means.

It is the most hostile environment to man, even going to mars is prohibitive.

Barring advances in rocket tech, we won't be colonizing anytime soon (20+ years away)

So for now, with out some new advancements, we can extrapolate from current ones.

We could foreseeable even print a person at some point, we are already working on complex structures like Hearts, at one point it could be possible to load DNA in a printer an create a body part, so why not a Body, say an infant?

Next, Computer tech if not AI, at the very least extremely smart programming could lead to some kind of robot "caretaker" to raise the humans that where born there.


There are alternatives, don't get me wrong, Drones exploring and setting up colonies could work, send 3d printing robots to a planet. Have them mine and produce.

But again theres always the problem of transporting soft fleshy humans through the harsh radiation of space, and with current trends in technology colonization is not practical with out thinking outside the box.

Shadow Herder


Do you consider the bible or other ancient lores as definitive history?

No, I don't. Not at all.

Keeping up with our HISTORY would be more important. And by that I mean our history.

I'm not a religious person, spiritual, yes, but not religious.

(Evolution, ancient civilization, how we came to build/invent A to Z, etc.)

If you are looking for a religious answer, you asked the wrong lady.

anon72
First thing they have to do is how to save human reproductive elements from
radiation bombarment once they leave the earth astromphere.

But, it that is possible you will have millions trying to get the hell of this planet and that would be there opportunity.

The Good, Bad and the Ugly would all be out.

Just a chance to get out from the thumb of danger from the less.... desired of our population.

You know the ones who are preditors and target humans.

It would be a very cool story or movie ( i want rights) about a massive ship with 10,000 ancient dead astronauts in a 2 thousand year old ship sent from another galaxy to earth in attempts to extend their race is found coming towards earth.

Rainbowresidue

Shadow Herder


Do you consider the bible or other ancient lores as definitive history?

No, I don't. Not at all.

Keeping up with our HISTORY would be more important. And by that I mean our history.

I'm not a religious person, spiritual, yes, but not religious.

(Evolution, ancient civilization, how we came to build/invent A to Z, etc.)

If you are looking for a religious answer, you asked the wrong lady.

edit on 9/4/2014 by Rainbowresidue because: Spelling,because it's Wednesday.

Unfortunate for many then that some of the oldest histories to survive are religious in nature or coincide with religious stories. History books are forgotten when not written in the tongues of the man of its time.