I'm working on a planetary colonization story where a crew of 36 women are sent to populate an earth-like planet.

The crew takes with them the tools needed to survive the first years. Enough to build the first houses and to plant the first fields, and a huge sperm bank, capable of storing thousands of sperm samples for centuries.

Each sample comes from a different donor, and the donors have been selected to optimize genetic diversity.

These samples are separated in two groups:

  • group A contains only sperm with an X sexual chromosome
  • group B is evenly distributed between X and Y

The colonists will start by using samples form the group A for a few generations, then samples from group B for one generation, and finally switch to regular reproduction methods.

With a fertility rate of 3 children/woman, the first generation will see the birth of 108 girls, the second 324, etc.

I want to keep the all-female phase under 200 years, but not endanger the life or well-being of the colonists. With 3 all-female generations and one mixed, we'll have 2916 both male and female children to continue the colonization process.

I'm assuming this is enough, but we can add as many generations as it takes.

All of this will be carefully prepared before launching the mission, including a set of cultural tools (like the language) which will be developed by a team of sociologists, anthropologists, linguists, and every useful expert possible.

My questions are:

Knowing the last person who had ever seen a man died decades before the birth of the first boy, how difficult will the transition be? How will the social order be impacted?

How should the first colonists shape the culture of their descendants (it can be through legends, traditions, rituals, songs, language, beliefs, etc. ) to ease this transition?

Edit based on the comments:

Colonizing a planet and starting a civilization from scratch is hard work. In this scenario, all the workers are also single mothers, and raising children is very time consuming.

I assumed they'll start having kids at 25 to give them enough time to build their home, reclaim fields from nature and conduct exploration missions.

Also, having to many kids with little medical care is a serious health hazard, so I think it's best not to over-do it.

Of course, not every women will have exactly 3 children, most will, but some will have more, and some will die young. 3 children/woman is the fertility rate for the entire colony.

I'm also thinking about setting this rate even lower (2.5, maybe only 2 children/woman). A slow and steady colonization seems preferable to me than a rushed one with a high mortality rate.

I'm not sure on the number of all-female generations, it depends on the minimum size the population needs to be to avoid inbreeding.

To give you an idea on how many years will pass between the landing and the first boy :

It takes 3+1 generations to have 2913 children, and 5+1 generations to have 26244. If the colonists have their first child 5 years after landing (to build the first village, secure the food supply, explore the surrounding region, etc.) and their daughter have theirs at 25, it will take between 80 years (3+1 generations case) and 155 years (5+1 case) for the first boy to be born.

Edit based on an answer:

About the first colonist culture: The language, social structure, stories and rituals will be created back on earth specially for this mission. The first colonist will learn them (they may be specially raised for this purpose, so they can learn as much as they need before leaving), and pass all this to their children and grand-children.

It's not about what could happen if we send a crew of multicultural people, but about what this created culture should be to keep the colony stable.

Third Edit:

Apart from the super-sperm-bank, the first 36 colonist only bring the tools they need to start over. These tools will serve a few decades, maybe a couple of generations, but then the colony will end up at as a rural economy, with access only to pre-industrial technology.

They also don't live in a ship, but in the houses they build with their own hands.

  • 2
    $\begingroup$ In this situation colonists will almost certainly start having children much younger and may have more than 3 each. $\endgroup$
    – Tim B
    Aug 12, 2015 at 11:30
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    $\begingroup$ Why would they all raise kids as single mothers? It would make a lot more sense to raise children in groups, say with three or four mothers all working together to raise their 12 or so kids, or else with one central child care facility raising all of the kids in the community. $\endgroup$
    – ckersch
    Aug 12, 2015 at 13:55
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    $\begingroup$ "Also, having to many kids with little medical care is a serious health hazard" - There are woman doctors, you know! ;) $\endgroup$
    – komodosp
    Aug 12, 2015 at 16:03
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    $\begingroup$ Why would it end up in medieval times if the technology + equipment + expertise is there? Maybe not the expertise, but the learning materials and the equipment is there, a minor degradation why not but medieval times is too much of a leap. (Except if there is a civil war and equipment is lost.) $\endgroup$
    – Jose Luis
    Aug 13, 2015 at 8:28
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    $\begingroup$ This is very interesting. It is also very dangerous. What if the fecundation machine™ breaks? They have no male, they are fucked. Or, well, they aren't (pun intended). Still it's very interesting, so please keep studying it. Please also consider what will happen when they will be supposed to create the first males: will they just do it, or, more likely, many of them will oppose and see no reason to risk their lifestyle? $\endgroup$
    – o0'.
    Sep 4, 2015 at 13:27

4 Answers 4


This is a complicated question, and really you can have whatever social construct that you like. Keep in mind that this would be a modern society though with computers, video records, etc. You can expect their traditions and the ways they are passed on to be much like our own are.

I doubt the society would be artificially designed, instead it would develop naturally over time. Certainly you should expect it to evolve considerably from whatever the first designers expected.

Clearly there would be a lot of lesbian activity since the desire to pair (or group) up and form partnerships would still be present even in the absence of males. Most people are hard wired to want intimacy and companionship. Some people would not take part in that but I'd expect it to be fairly prevalent. As a result homophobia (certainly for female on female activity) would be very rare or non existent.

With the separation of sex and reproduction then the society's attitude towards sex is likely to be fairly liberal (although it could go the other way of course). Jealousy will still exist of course as its part of human nature but a lot of our own cultures hangups about sex are unlikely to be carried on.

People would start having children from the age of around 16 to 18 and they would carry one child every few years. People would get some say in the timing but probably only get limited choice as to the father which would be selected based on genetic studies.

Children would most likely be raised in group creches and an extended family built around them may well develop. You may even see a large extended family forming with 5 adults, 10 older children and 10 younger children (numbers will vary of course) forming. As children grow older they spend more and more time looking after the younger children so the adults have little child-care responsibility and can focus on the colony's survival.

Education would be handled by computer software aided by the older children.

When the children reach adulthood they either stay in the same family, move to another one, or join up with other like minded people to form a new one.

The introduction of the first male children into this is obviously going to be a big deal. Since every family group will most likely introduce them at the same time though they will quickly become accepted. The children have never known anything different, while the adults will have time to adjust as the boys grow older. A lot of the stereotypes about men and women that we have would not exist in this society so the men would grow up around the women and raised by the women.

No doubt there would be a number of older women getting it on with the younger men, in fact the first few males to reach adulthood are going to have no shortage of offers. Many other women though will be very used to the concept of finding other females attractive and so just the existence of a male would not interest them. It could almost seem like a bit of a strange fetish for people to fancy men and be treated in a similar way to how fetishists are in our society.

It's likely that the first male generation would not be a 50-50 split. Instead a smaller proportion of males would be introduced and then over time and as natural conception becomes more common this percentage would rise.

10% males for example would be enough to reduce the dependency on the sperm banks remaining functional and remove them as a single point of failure for the whole project.

  • $\begingroup$ Thanks for the idea of introducting males progressively. I maybe should have mentioned clearly that the first generation will be of only 36 people and their tools. The first 2 or 3 generation will have access to some modern tools, but the colony will quickly return to middle-age level of technology (exept for the magical space sperm bank of course). I'll edit my question. $\endgroup$ Aug 12, 2015 at 16:40
  • $\begingroup$ " lot of lesbian activity since the desire to pair (or group) up and form partnerships ... Some people would not take part in that but I'd expect it to be fairly prevalent." Don't we largely assume these days that sexual preference is genetic? Mightn't we end up with a large number of unfulfilled-feeling colonists? $\endgroup$
    – akaioi
    Oct 11, 2017 at 18:57
  • $\begingroup$ @akaioi Evidence suggests that desire is on a spectrum (for example see the Kinsey Scale) (and that physical attraction and romantic attraction can be on a different spectrum). Societal pressure tends to push everyone to "pick a side" and up to recently heavily pushed them towards the traditional sides. With that pressure removed though a lot of people (not all, but a lot, and increasing over time) would be more flexible in their choices. Some people are just gay, some are just straight. Many though fall somewhere between the two extremes. $\endgroup$
    – Tim B
    Oct 20, 2017 at 12:49

I'm pretty sure your society will not survive.

You are asking about the impact of women-only generations, and the reintroduction of males to this society - the answer (if they survive that long) will be generations of gender discrimination and stereotyping, and the very real threat your society will simply fail to follow a plan, whose last adherents are decades gone - which will again lead to the loss of your society. I mean, there's a bit of a chance (and no guarantee) your planet will have human people living there, but your carefully-planned society... no.

So, first. You have a single point of failure, or actually you have a chain of single points of potential failure, that can easily destroy your colony because there are no backups or alternates, the situation of which is planned to persist for 80-200 years. Your fecundation machine, is a problem. Given the plan that the colony is lower tech than the parent company, the odds of someone being able to diagnose or fix the machine if it breaks, or if something goes wrong, is pretty low. Or if not the machine, the sperm bank. Or any of the steps or processes along the way. Even if you ritualized it into religion, the chances of something going wrong they can't figure out how to fix, is pretty high - considering you're gambling with the only thing that will let the colony survive.

Next, you have the problem of generational culture. I would honestly not expect any planned influence from earth to last beyond three generations - that is, the grand-kids of your colony ship - if it isn't day-to-day relevant to each generation. They can tell stories, and teach lessons, and plot and plan a great deal - but the kids are growing up in a different world, a world which needs their immediate attention, for survival. The kids will be creating their own culture and customs, and while their parents will have some influence, their grandparents will have much less (probably only limited to stories and advice). I'm drawing from ideas of how immigrant generations adapt, as a start - not a perfect analogy, but something. The point is, the 8th generation has no real reason to obey the words of the first-generation, not if it will destroy their culture, not if they can't see the need for it, not if they're afraid. So all your careful "cultural" planning will probably not work, at least not beyond a few generations.

Next, the reason they might not "reintroduce" the males. In this scenario, you have 8+ generations of a female only society - with customs, and culture, and stories, and the whole of living memory reinforcing the way things are done - and you're asking them to uproot all of that, to reintroduce strange creatures that they have only vague stories about, to change fundamental parts of their society (including stories of very different families and lifestyles from the first colonists, I'm guessing). It's a sudden shock, an upheaval, that will destroy their society as they know it - and they will want to avoid it, especially since it is within their power. And when they do confront it, it will certainly be about them and their culture, not the bedtime-stories of those generations ago, that guide how they will react.

Some will just not want to - after all, they have a method that works, why change it. Some of them will see men as only for breeding - after all, they haven't been needed until then, so probably not that useful. Some will be frightened of the concept of natural reproduction, and of the idea of men. Gender stereotyping and gender discrimination will be rampant, any physical difference (however slight) will be exaggerated and demonized, and the matriarchy will consolidate itself to keep power and keep these "men" in their proper place. All of these will occur anyway, given the size of the social change - but culture can play a big role, even if they can't eliminate any of these possibilities.

So, the setup post-reintroduction of men, is going to be a bit like the patriarchy, and the gender discrimination that rose up (and that we've spent so much time trying to undo the harm from), on earth. I'm really kinda not sure why you want that to happen (though I guess lots of storytelling opportunities), so maybe why does your colonizing society want that to happen - because there's just no way it won't.

There is a non-zero chance that your society simply won't reintroduce the men on schedule, and go with the fecundation machine until it breaks, in which case your society is doomed. Maybe they'll wait until "later", where later is a few generations before the machine stops working - except, oops, that kind of later is much easier at finding "too late" rather than "just before too late". Maybe they'll frantically try to figure out cloning or other alternatives to reproduction, and probably fail - or try to "fix" the machine, or recreate it, because by now they probably don't know enough about reproduction the natural way to know why it won't work. Maybe by the time they run out of group "A" and have to start on group "B", the society is large and strong enough (and set enough in its ways) that men are raised as slaves, and only used for reproduction. Maybe they'll move on to group "B" when they run out of "A" - but practice infanticide on the males, so they don't have to change their culture, until the machine runs out (either formally planned as a society, or individuals making the "safe" choice with unintended consequences).

So, after all that, what can you do that will work? Start with a few (one or two) boys in the very first generation, and keep the tradition going. Given you're talking about dropping the reproduction rate from ~3 kids per woman, to maybe ~2, you can probably afford a few extra kids in each generation. Even if there's fewer of them, you have your generations of women growing up alongside men, you can teach lessons of how people (both male and female) should be treated and those lessons will be passed down, because they're relevant and being used by each generation.

Even a few boys from the beginning means your colony isn't solely dependent on equipment and procedures they can't repair or perhaps even understand. You can still build up your population and diversity with generations of mostly women, but without the trauma that would come from 'reintroducing' men with no clue, no experience, and no way to tell what was true and what was just stories. Even a few boys each generation will mean your colonists grow up alongside them, and know that they are people, and are taught early enough (when the originals know what's at stake) to treat people right - and the lessons can get passed down because they're used and needed, so will probably last a lot longer than if they're imposed on people and never used otherwise. And even a few natural reproductions each generation means that people will know what is supposed to happen and how, fewer people will be afraid, and the transition from fecundation machine to natural reproduction will be much smoother.

Teach them about inbreeding and why the gender balance was intentionally skewed, so that bringing the balance back up to equal won't be such a shock. There will be a few natural reproduction situations each generation, but between being taught about inbreeding, and birth control, and families being encouraged to also have kids by fecundation machine, it will probably be manageable - and, really, they will have learned and passed down the lessons about inbreeding while they still made sense, while your women-only generations probably would have forgotten or gotten the rules all mixed up because the situation didn't match the rules for so very long.


Well there are a few things about this scenario that are a little troubling. 36 people are not many when you consider that they will be on their own with no reinforcements for generations. I'm not just talking about the gene issues. colonizing is hard work and has a reasonably high mortality rate. Medical supplies and knowledge will be limited. Though to use a sperm bank successfully will still need some decent medical equipment.

The 'sperm' bank. While you can have thousands of men represented there, every single person will have one of the 36 Eve's as a progenitor. Mixing in the 'x' chromosome from the sperm will help, but there will definitely be 'blood-lines'. This would also likely create a very strong matriarchal society.

The next issue I see is

I assumed they'll start having kids at 25 to give them enough time to build their home, reclaim fields from nature and conduct exploration missions.

This first assumes that they are colonizing a planet similar to Earth with abundant life and it's somewhat compatible with our existence. You can't really compare this to colonizing a different continent.

Whether or not you find a planet with life or not on it, it will take years of careful study to build a 'village' to safely live in on the planet itself. If there is life, you have no idea how dangerous it is, and what you need to deal with. If it doesn't have life, then the chances of it having much breathable Oxygen in the air is pretty slim. So they would have to build domes.

One last issue, is the length of the trip to get to the planet. How do you get 36 women there without them being way to old to bare children? They will be needing to reproduce in the ship along the way, or be in some kind of Cryo-statis.

Knowing the last person who had ever seen a man died decades before the birth of the first boy, how difficult will the transition be? How will the social order be impacted?

Men will become a 'legend' and depending on how the first group viewed men, would have a huge impact on how they are treated during reintroduction. I do suspect most will be interested in seeing something new, and finding out about them. But the first few hitting puberty will be a bit of a shock, no matter what they were expecting. On top of that, the first boys/men will not really have any role models to help them mature. So interesting times.

How should the first colonists shape the culture of their descendants (it can be through legends, traditions, rituals, songs, language, beliefs, etc. ) to ease this transition?

Definitely keep as much material available to help 'learn'. Books, and videos if possible. Likely keep stories about the more positive aspects so the young men will have positive role models to shape their lives. With of course some cautionary tales about the ones that go bad. Remember, the vast majority of Serial killers are male!

  • $\begingroup$ Men need not "become a legend" if they have the books and videos you mention. "And some day, things will be like that again, only better" $\endgroup$
    – WGroleau
    Dec 11, 2017 at 4:41

Miscellaneous ideas and remarks

  • 1st I hope you take into account that the 1st colonists shouldn't be fertilised at once and you'll need some kind of medical care for them during the pregnancy and afterwards for the babies/children this alone will be a hard and challenging work. This would mean that some of the 1st colonists should be pregnant earlier then others therefore 25 might be to early for some or too late for others.

  • Have you considered the possibility that a boy of the 1st or in general an earlier generation could be have a sexual relationship with a woman of the age of his "mother"?

  • I think the boys will need some kind of authority this would mean some of the 1st colonists should have such qualities. This means there should be some kind of hierarchical structure with a strong personality at the front!

  • I think you need the 1st colonists to be somehow polyvalent, as you might need scientists, doctors, nurses, midwives, as well as farmers, clerks etc. an other big challenge!

  • What if females with time would dislike natural fertilization? How would males react? Is it possible that male have also problems with this?

  • Are there any moral aspects, laws, religion? can a male Line of ancestors be related with a female which crosses his line somehow? Or should they try to find a partner with a different ancestor Line? -> incest allowed or not? How many generation should be a common ancestor away?

  • Will an elder female accept a male of a later generation becoming their senior?

  • Will male have problems getting higher positions in this society which was before ruled by a female hand?

  • Will this colony have social/emotional/sexual problems during the time between the 1st colonists and the 1st generation of potent young males?

Now to how the culture should be shaped:

  • hm... i guess some of the 1st colonists will have stories of their parents grandparents to tell, maybe they remember some kind of rhymes and songs ... with the time (the mix of) both of them may end up as legends. Rituals could also be a consequence from legends: "Our Fathers used to do this this way so we follow their footsteps" and Rituals may end up as beliefs in some cases! But this would mean that the 1st colonists have a common language (as you mentioned) and document their thoughts, experiences, tales....

  • And maybe in the preparation of the mission there should be a focus on how to raise boys as there won't be any until the 4th generation and this knowledge should be passed from one (female) generation to an other

  • I assume that in the preparation the cultural stuff will be some how indoctrinated to have a common culture: common culture-> common memory-> need of a kind of documentation (legends, beliefs, rituals to define it)

  • $\begingroup$ Thanks for the ideas and remarks, especially about spreading the first pregnancies in time. i'm talking about a "first boy", but at this stage, a lot of children are born every year, the boys will find plenty of girls their own age. $\endgroup$ Aug 12, 2015 at 12:51
  • $\begingroup$ About the first colonist culture: The language, social structure, stories and rituals will be created back on earth specially for this mission. The first colonist will learn them (they may be specially raised for this purpose, so they can learn as much as they can before leaving), and pass all this to their children and grand-children. It's not about what could append if we send a crew of multicultural people, but about what this created culture should be to keep the colony stable. $\endgroup$ Aug 12, 2015 at 12:57
  • $\begingroup$ @SpaceLizard i'm just curious: in your plot are there no more males on earth? if yes, what happened to them? Or will this be a parallel civilisation/colony? $\endgroup$
    – Medi1Saif
    Aug 12, 2015 at 13:02
  • $\begingroup$ For the boys difficulties: I don't think it will be a problem, in some cultures young people marry with little to no sexual education and still manage to have children. Plus they will know "where to put it", because since they grew up in a rural society, they already know how animals mate. Give the new generation time and a place to be alone and they'll figure it out. $\endgroup$ Aug 12, 2015 at 13:08
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    $\begingroup$ @SpaceLizard i think if you want to avoid a "lesbian" planet you should "produce" males much earlier $\endgroup$
    – Medi1Saif
    Aug 14, 2015 at 7:59

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