Here is something a bit more rigorous related to my Kepler Bb Civilization
I thought 100 humanoids transported with these criteria:
- 1:1 male:female ratio
- No children below 15
- No ill or otherwise diseased people
- and No pregnant women
would be enough. But now I don't think it is.
Here is a more detailed view of why I think it isn't. Primarily population growth.
First of all, their pregnancy is long. More than an earth year in all cases but lets assume Kepler years are being used. If 1 year is 20 months then their singleton pregnancy is 9 months(just to simplify things).
Here is a list of pregnancy lengths related to number of babies:
- Singleton: 9 months
- Twins: 12 months
- Triplets: 15 months
- Quads: 18 months
- Quintuplets: 21 months or 1 year + 1 month
- Sextuplets: 24 months or 1 year + 4 months
- Septuplets: 27 months or 1 year + 7 months
- Octuplets: 30 months or 1 year + 10 months
- Nonuplets: 33 months or 1 year + 13 months
- Decuplets: 36 months or 1 year + 16 months
- Undecuplets: 39 months or 1 year + 19 months
Dodecuplets: 42 months or 2 years + 2 months
This is all the possible numbers of babies in a viable pregnancy from 1 to 12 and their respective lengths.
Now how are all these viable? Well as you can see, for each baby added, the pregnancy extends by 3 months. At the 6 month mark all except 1 baby stops growing. But these are preserved in the womb. Once 1 baby is born another begins growing again until it is born and this continues for every baby in the pregnancy. The singleton is the only special case here. With singleton pregnancies there is no diapause whatsoever.
Inbreeding vs Outbreeding
Outbreeding is what I am aiming for to be the majority. This is why I put the 1:1 male:female ratio as 1 of the criteria. I knew that deviations in either direction from a 1:1 sex ratio lead to more inbreeding. And inbreeding while beneficial in some cases to increase diversity in a low diversity population or to enhance a trait is usually not what you are aiming for.
I have been told to have a 1:10 ratio where every man has 10 women. But this would lead to massive inbreeding in the second generation and beyond and eventually nobody.
Let me give you an example of 22 people in a 1:10 ratio.
Everything goes fine in the first generation but there is lower diversity than there should be because of the low number of males(just 2). In the second generation, not everybody can outbreed and so inbreeding occurs and lowers diversity. Inbreeding leads to more inbreeding until the whole population dies off. Not good.
Graphically it would look something like this after several generations:
An exponential decay graph
With a 1:1 sex ratio however, there is much more outbreeding than inbreeding in all generations and this would lead to more diversity and higher population.
Graphically, it would look something like this:
An exponential growth graph
Clearly, the closer the ratio is to 1:1, the better off for the civilization as a whole.
Lots of other things factor in but Illness, despite there being a severe viral illness called Viral TB that can and does affect all systems in more or less a cycle, isn't that much of a contributor to death rate. The reason? These people have a super tough immune system and a fast acting immune response to venom and poison that is beneficial, not harmful, at least in most cases.
Babies and immunocompromised people(in this case immunocompromised would pretty much only be genetic or as a side effect of treatment) are really the only people here with a significant chance of death from illness.
All the other major factors are positive ones(increasing birth rate):
Young and old both. Old moms have a higher chance of multiples and young moms have a higher chance of pregnancy.
Diet. Their diet varies but is abundant in vitamins, minerals, and protein, good and essential for supporting pregnancy with as few negatives as possible. In fact these people can digest bone slowly but surely into calcium, phosphorus, iron, and other minerals as well as whatever proteins, carbs, fats, and nucleotides are in bone(as far as percentage is concerned for those macronutrients). This helps them give the needed calcium and everything else to the baby while using as little of their own bone as possible.
Year length. This one is obvious. The longer the year and the more months in a year, the more that can happen in that year. For example, 1 incredible mom can have 3 pregnancies start in 1 year, all singletons or 2 twin pregnancies start in a year, etc. while a different mom, one that needs wet nurses to be with her at all times, might have 1 pregnancy in 2 years but have 12 babies in that pregnancy. I am not sure what a reasonable percentage is for each type of pregnancy, nonetheless subtypes(MoMo twins, Identical twins + singleton(type of triplet pregnancy), etc.).
Given all of this and that I don't think 100 people is enough(excluding Robin, Lisa, Alma, and the twins) what is a reasonable starting population? I don't want it too big(like a million would be too big for starting a civilization in early times) but I also don't want it too small(like a hundred would, I think, be too small for inbreeding to not be a significant minority(at or more than 20% of total pregnancy rate)).
The initial 100 people transported are not really transported in the sense that a space ship takes them from their home planet to a similar planet relatively close by. They are teleported from their home planet to Kepler Bb which happens to have a similar environment and gravity. Pregnancy could cause complications in any form of interplanetary or intergalactic transport, even if there were no complications from outer space itself. And 15 is the lower boundary for adolescents of this species and obviously if you have ill or otherwise diseased people, this can cause complications whether it be an illness spreading or passing on the disease via genetics or worse, death from that illness or disease.