How fast can a colony grow?

[Darmalus]

You are the leadership of a colony. You have an Earth-like world to yourself with no environmental, biological or other hazards any greater than in an equivalent biome on Earth. Due to political shenanigans, you are on your own for a few decades until everyone on the homeworld calms down and stops embargoing you.

Your overall goal is to give this planet a great big population of technological humans. How fast can you grow the population?

You have a culture that is amendable to having larger families.
Cloning, exo-wombs and immigration are not options.
You MUST maintain your technology. Fortunately the raw materials are found both on the planet and in easily reachable space, so its mostly a matter of maintaining your workforce.
Advancing your technology is not a priority.
In terms of education, a colonist is a useful general purpose worker at age 18, general education plus trade school then entered directly into the workforce as an apprentice or some sort. Various high end specialists take a few more years, but they are a tiny segment of the population over all.
The average person can be a useful worker until age 90, and will usually see their 110th birthday before dying.
Menopause still happens, but medical science has reduced it to an insignificant annoyance.
Technologically they have anything we have today, but faster, cheaper, safer and more reliable.

[Jub]

We need more information to even make a guess. How many colonists arrive to start? How fast can housing and supplies be ramped up to accommodate new people? Are the women open to the idea of birthing a child per year and at what point do they call it quits?

[Darmalus]

A round 1 million colonists, who arrived or were born over a 40 year period before you and the homeworld decided you wanted nothing to do with each other.

As far as construction, assume our real world best is their standard and unremarkable. Their primary power is both nuclear fission and fusion. Fission is built, installed and replaced as no-maintenance sealed units for specialized purposes. Fusion fills the standard power demands. They can get the same high intensity farming we can, but can efficiently reclaim the waste to avoid the ecological consequences we get now.

How many children per woman per year is the tricky one, since I honestly don't know enough. I suppose we can assume the 1 child a year as an extreme (and unrealistic) upper limit and scale down from there.

[biostem]

As Jub pointed out, knowing the starting population AND they ration of men to women, would be very important. Additionally, if cloning and artificial wombs are not an option, how about fertility treatments and/or artificially triggering twins/multiple child pregnancies? Things like controlled acceleration of growth or genetic engineering to delay the onset of bodily wear due to aging would also help extend the useful population. Heck, if space is "easily reachable", then there may be the technology to construct simple humanoid robots to aid in general work, and more specific machines to assist with other forms of labor/manufacturing/food production/etc.

[Darmalus]

As a colony they don't have all the bells and whistles the homeworld does, but they do have better technology that we do now. Anything we can do (or theoretically do), they can do, just more cheaply and reliably. Part of that assumption is better automation. So if we can artificially trigger twins, so they can they. If we can't, the homeworld might be able too, but the colonists had to leave that behind for reasons.

The only true sci-fi they have is the ability to traverse space quickly at sublight speeds without insanely huge rockets. So traveling to the local asteroid belt for space strip mining is several days journey and a few months living at the work site. Like working a really remote place on earth now.

[biostem]

Well, we certainly have fertility treatments in today's world, and instances of multiple births, (like Octomom), were the result of said fertility treatments, so if a society is more advanced medically and technologically than us, it may be reasonable to say that they can induce multiple births intentionally.

Also, if said society isn't against child labor, they could have, say, 12+ year olds assist with some of the workload, (I'm not saying manual labor here, but perhaps they could be evaluated and trained to perform non-hazardous tasks or do things like operate drones, etc).

[Lord Revan]

it should be noted that resources are within a reasonble distance from the colony site will effect how well a colony will grow, after all you can't feed more people then you got food for, just to give an example.

[Borgholio]

There was something like this awhile back where someone pondered what would happen if the Augments from Star Trek : Enterprise actually founded a colony on their own. The general consensus was that the colony would not grow very fast even with help from cloning or artificial wombs, simply due to the fact that food has to come from somewhere. Sure you might be able to double your population every year or two with the right tech...but how could you feed them?

[Korto]

I remember, from some research I was doing for world-building, reading about a tribe who really believed in having lots of children, and they averaged 12 children per woman, but I'm buggered if I can find it again now. Anyway, that could be considered a practical maximum average without any modern intervention.
Individually,

The maximum number of offspring credited to a human female is 69, to a 18th century Russian woman that repeatedly produced twins. The Guinness Book of World Records cites a living Argentine woman who has given birth to 38 children.

What could be interesting would be how the colony copes with them all. Would they have a communal culture, with all the children being looked after by everyone? Or is it individuals looking after their own, like us, but with massive government support? Are they encouraged to have children, and then abandoned without any support, resulting in mothers stuck at home, unable to cope, and suicides soaring?
Food might not be a problem, we can make incredible amounts of food per producer now, but the strain of caring for them is another thing.

[Zixinus]

We can produce lots and lots of food on Earth, where there is massive amount of space and soil. If your colony planet is sufficiently Earth-like (in details relevant to biology) and your plants grow without a problem (presumably genetically engineered to the planet), then its a matter of how much you can make use of.

If it is just Earth-like enough to be comfortable but the existing biota is alien, then you have a problem. You have to destroy existing biota habitats to make way for your food production. Alien parasites, vermin and competitors are going to slow your rate down.

Weather may still play an influence. It is no worse than home's, sure, but that can still be pretty bad from time to time.

Another thing that can slow down food production rates is how diverse your food sources is. A modern country can provide food for itself fairly well, but partially because of globalization allowing excess food to be brought from other countries (made by people that your country does not have to feed). Even subsistence farmers make diverse farms at different elevations, seeds, soils, etc rather than focus all their effort into one large plot. This is to ensure a minimum supply of wood, because you are segregating possible crop failure.
Modern equivalents have to made for your colony. You want your food crops to be made in different ways at different places.

You are also not just limited with how much food you can produce overall. But how much you can gather, process and store. You do not want a famine if you have a bad year. You also want to have a large buffer bare minimum and overproduction. In one year you might get an overall harvest of the latter while you can get an overall harvest of the former.

So yeah, you want a large buffer between how much you can feed a colonist and how fast your colony can grow.

[Lagmonster]

Zixinus is probably even understating the problem. If you have no existing food supply systems and have to effectively begin agriculture, you are so seriously fucked. I've tried re-writing a sentence three times that lists the worst of the problems facing colony farmers, and there are so many - most of them serious - that it's damn hard. Fuels, fertilizers, pesticides, length of day, quality of sunlight, humidity of the air, temperature, ecological compatibilities, pest control, storage, spoilage, transport, soil quality - fuck, what IS the soil here? What's it composed of? What is living in it and off of it?

Your colonists are very, very fucked unless they can eat the local flora and fauna.

[Lagmonster]

Actually, giving it more thought, since I know that supply chain from earth will be re-established inside of a generation, I'd probably advise AGAINST rapid growth. Limit to replacement or slow population growth. Take it easy, develop a small, stable colony first and add population as more of the native support infrastructure is completed and comes online. Unless, again, the planet is an improbable paradise where there are no natural threats to our species and we can survive buck naked in the sun and eating the local flora right off the trees or something.

[Guardsman Bass]

I don't think the local flora and fauna could eat your plants (too genetically different), although they could still compete for the same nutrients, sunlight, and space in the soil - and they'd have the advantage of evolving under those conditions. It would be too energy-intensive to bake all the soil you're going to use before mixing it with bacteria and fungi from Earth, so you'd instead have to mix it with those and hope your plants then take to it.

If you have today's technology, you could grow stuff hydroponically until if or when that works. But I agree in the mean-time, a rapidly growing population is a bad idea until your ability to expand the food supply is secure.

[Simon_Jester]

Yes.

On the other hand, once you know you can rapidly expand agricultural infrastructure and it stops being a bottleneck, the previous discussion comes back into play.

[Lord Revan]

It should be noted that while I did use food as and example it's far from being the only logistical problem a self-suffient colony would have and also there will be administrative problems that would arise at managing a larger colony and would thus limit the growth potential

[Broomstick]

How many children per woman per year is the tricky one, since I honestly don't know enough. I suppose we can assume the 1 child a year as an extreme (and unrealistic) upper limit and scale down from there.

Most women are not Michelle Dugger. I would say one child every TWO years, and if your women also nurse space that out to 1 every 3 years. Annual childbearing will have a bad effect on the woman's reserve of essential minerals like calcium and iron and greatly increases the risks of complications like uterine prolapse and incontinence.

If you REALLY want to produce kids the women can start a year or two after menstruation starts - in our times, around 14 or 15. Assuming they hit menopause at 45-50 that's about 30-35 years of child bearing and about 15-17 kids per woman (assuming 1 birth in 2 years) or 10-12 (1 birth in 3 years) if all children are singletons (but there will be twins and occasional triplets naturally). Not everyone will be able to hit those marks, of course, but you'll probably need people to help the women do all the child-caring and rearing of these broods.

Of course, the women may not be happy about being brood mares.

As Jub pointed out, knowing the starting population AND they ration of men to women, would be very important. Additionally, if cloning and artificial wombs are not an option, how about fertility treatments and/or artificially triggering twins/multiple child pregnancies?

Humans haven't really evolved for routine twins and triplets. Multiple child pregnancies nearly always result in premature deliveries and lower birth weight babies. Risks of complications are significantly increased for both mothers and children, including some pretty hair raising ones that simply can't occur with singletons. Without late 20th Century medical tech you'll wind up with fewer kids in the end, higher maternal mortality, and the survivors will be more likely to be crippled. With better medical tech you'll get better results but at greater expense and resource expenditure.

Of course, if you don't give a fuck about the women as human beings you can do all sorts of awful things - force annual childbearing and if they die of osteoporosis with their uterus hanging down around their knees and piss dribbling into a diaper a year after menopause who cares? If you're willing to kill the women you can get a lot more than 12-15 kids out of them on average before they kick off. Treat them like the axolotl tanks from the Dune universe and you'll get vastly different results than if you treated them as actual human beings.

What kind of society are you looking at?

[Guardsman Bass]

The exile lasts for, what, a few decades? We don't really need to expand the colony so much as we just need to breed enough to maintain it until we re-establish contract and trade with Earth.

I was thinking about the interaction between our bodies and the local bacteria/biota. Even if they don't really react in the sense that the alien bacteria can't infect, they might still do stuff like getting into our mouths and lungs and going "Ooh! Warm, moist area! Grow!", giving us issues with inflammation when our body treats alien bacterial growths as foreign bodies to be encapsulated (a common problem with other stuff getting put under your skin, like implants). But I"m not a biologist, so I'm less certain about how our body might react.

[biostem]

How many children per woman per year is the tricky one, since I honestly don't know enough. I suppose we can assume the 1 child a year as an extreme (and unrealistic) upper limit and scale down from there.

Most women are not Michelle Dugger. I would say one child every TWO years, and if your women also nurse space that out to 1 every 3 years. Annual childbearing will have a bad effect on the woman's reserve of essential minerals like calcium and iron and greatly increases the risks of complications like uterine prolapse and incontinence.

If you REALLY want to produce kids the women can start a year or two after menstruation starts - in our times, around 14 or 15. Assuming they hit menopause at 45-50 that's about 30-35 years of child bearing and about 15-17 kids per woman (assuming 1 birth in 2 years) or 10-12 (1 birth in 3 years) if all children are singletons (but there will be twins and occasional triplets naturally). Not everyone will be able to hit those marks, of course, but you'll probably need people to help the women do all the child-caring and rearing of these broods.

Of course, the women may not be happy about being brood mares.

As Jub pointed out, knowing the starting population AND they ration of men to women, would be very important. Additionally, if cloning and artificial wombs are not an option, how about fertility treatments and/or artificially triggering twins/multiple child pregnancies?

Humans haven't really evolved for routine twins and triplets. Multiple child pregnancies nearly always result in premature deliveries and lower birth weight babies. Risks of complications are significantly increased for both mothers and children, including some pretty hair raising ones that simply can't occur with singletons. Without late 20th Century medical tech you'll wind up with fewer kids in the end, higher maternal mortality, and the survivors will be more likely to be crippled. With better medical tech you'll get better results but at greater expense and resource expenditure.

Of course, if you don't give a fuck about the women as human beings you can do all sorts of awful things - force annual childbearing and if they die of osteoporosis with their uterus hanging down around their knees and piss dribbling into a diaper a year after menopause who cares? If you're willing to kill the women you can get a lot more than 12-15 kids out of them on average before they kick off. Treat them like the axolotl tanks from the Dune universe and you'll get vastly different results than if you treated them as actual human beings.

What kind of society are you looking at?

The OP mentioned that the tech level allows for everything we can do currently, only better - that, IMO, also includes the safety, health, and well-being of both the mothers and babies. I'm not advocating turning these women into horrible baby factories - but if repopulating the species is of paramount important, and the risks are minimized, while health and confort are maintained, they let them have twins. Just because *current* fertility treatments are spotty and potentially unsafe, this advanced society need not have those issues...

[Broomstick]

The problem with twins is not the "fertility treatments", the problem is trying to fit what should be 16 pounds of baby into a space evolved to fit, maybe, 10-12 pounds. That's why twins tend to be born early and underweight and triplets even more so. When the total mass of babies of babies hits around 10 or 12 pounds (at most!) the uterus tends to pull the flush handle. A quick google says most human twins weigh an average of 5.5 pounds at birth (for a total of 11 pounds of baby) and triplets average 4 pounds each (for 12 pounds of baby). With multiple babies all trying to reach a normal 7-8 pounds at the same time this will happen BEFORE any of them are done "cooking".

Short of installing larger uteri in human women this isn't going to change. It's not technology, it's biology.

Sure, human twins used to survive before modern medicine but it was invariably touch and go for the first couple months. Incubators compensate somewhat for early birth and low birthrate, but they take resources, energy, and time to utilize.

So no, I don't think making every pregnancy produce twins is a good way to go about increasing the population unless you don't give a damn about the effects on the women and you don't give a damn about the kids who will die or be crippled by the effects of premature/low weight birth.

[Darmalus]

What kind of society are you looking at?

I have no one but myself to blame, really. I left out a bunch of back story since I figured no one would be interested and just boiled it down to an abstract problem.

The colony is embargoed because you managed to actually pull off a largely bloodless secession through a combination of opportunity, timing and blind luck. Because of this, you don't fear any sort of violent retaliation. You were just embargoed and called mean names, more violent secession attempts you possibly inspired were crushed with high body counts.

What you DO fear, however, is invasion via colonization. Your grip on this planet is tenuous, and it would be perfectly plausible for the homeworld to get its revenge by flooding your planet with loyalist colonists and claiming every scrap of M-class planet you don't have a firm grip on via squatters rights. You estimate you have several decades due to insight into homeworld politics and knowing that this wave of secessions (successful or not) has caused them to completely tear down the old colonization authority and start rebuilding it with a much stricter screening process. This will slow their recruitment to a crawl compared to the old days.

I wanted to know how fast the colony could grow to see if holding the planet was plausible, or if a bigger seed colony would be needed. I was mostly imagining the colony government encouraging "more babies" in a manner like victory gardens. Do your part, we shall claim this world, don't let those homeworlders steal our destiny, yadda yadda.

[Simon_Jester]

I don't think this is winnable for the colonists, especially if Terra is prepared to dump small populations of squatters and claim large currently unsettled areas. These colonies don't have to be sustainable, after all; they just have to occupy ground. And if the local first-wave settlers try to push out the second-wave settlers... so much the better, says a cynical Terran politician.

Given your colony's need to be self-sustaining in pretty much all ways, you'll get less traction out of increasing the population than you will out of decreasing the density, and spreading out small outposts over large areas to discourage anyone from landing.

Then again, if Terra is motivated enough, their settlers will plunk down and set up shop whether your outposts like it or not.

[Kingmaker]

A really simplistic and absurdly optimistic model should give you your answer. Given ~40 years, a starting population of one million, unimpeded exponential population growth (unlikely), and 10% growth rate (really unlikely), you're looking around 50 million people. So you can cover an area about twice the size of Texas at a comparable population density (100/mi^2), or an area about the size of Australia at comparable population density (7/mi^2). You may have a hard time selling that to Terran immigrants, though.

I need to emphasize: 10% annual growth is absolutely fucking ridiculous.

[madd0ct0r]

plausible at the the start though - it's not like there's a death rate initially.

on the farming limitation. If we assume optimised GM algae in thin skinned grow bags, you can sidestep the whole alien flora. Something like this in cross section, but maybe a 100m long for each one.

Lay them out in long loops from a central pumping system. the furthest point is the highest, you just pump up one branch and it runs down the other. Opaque bottoms keep the local flora down, transparent greenhouse effect. Rainwater (you need a lot of water) is collected on top of them and flows back to the main plant. Split it with electricity, burn it as fuel when you need to and keep the new pure water for the algae. Tubes are just a thin film plastic that can be extruded with low material and energy cost.

Overtime, bio film will build up on the inside of the tube, making it less and less efficient. Options
1: empty tube into new one, scrape clean
2. emtpy tube into new one, shred, dry and burn for energy
3. introduce snails as a yummy snack.
ect.

Assume you get the algae to work at max likely efficiency =4.3% (max theorectical is 6%). If you know how many kcal you need for people, plus a huge safety margin, and you know how much sunlight energy is available, you know the area you'll have to cover per person.

[PKRudeBoy]

As far as population growth goes for the first generation, the starting gender ratio and whether the culture is open to polygamy would have a huge impact. If the colony starts out 80-90% women it could grow much faster then with a 50/50 split. How that would effect the colony generations down the line when the population swings back to normal, I don't know.

[Purple]

As far as population growth goes for the first generation, the starting gender ratio and whether the culture is open to polygamy would have a huge impact. If the colony starts out 80-90% women it could grow much faster then with a 50/50 split. How that would effect the colony generations down the line when the population swings back to normal, I don't know.

Can it really? Sure there are more wombs to get pregnant but at the same time pregnant women can't well work the fields to feed all those children unless you practice some interesting timing.