When the humans start mating on my generation ship(so after survival training), there should be at least 100 pregnant women as a result. I mean per 1000 women in the united states that are married there are up to 114.1 pregnancies which is close to my minimum of 100. I mean ideally the majority of the women should become pregnant but even a minority is significant.
Now first, I thought that nocturnal-diurnal pairs shouldn't be allowed to avoid emotional upset from 1 person being tired and the other wide awake. But then my momma told me that I could allow a nocturnal person and a diurnal person to mate during the small overlaps(so twilight).
Now the nocturnal people don't get any less sleep or less quality of sleep so you don't need to comment on that.
What I am trying to decide here is whether or not the people should be monogamous or polygamous.
Case 1: Monogamous
This is what I favor and what my momma favors. Sure you might get a low reproduction rate with monogamy but so what? For one thing, monogamous doesn't mean you can't be with your friends 1 day and your partner the next. As long as you mate with 1 and only 1 person during a given period of time(breeding season or lifetime(so you might mate with 1 male during 1 cycle and a different male the next cycle, that is considered monogamous, it doesn't have to be for life)), you are monogamous.
Another reason I favor monogamy is that the lower reproductive rate means more care per child and it also means that population growth doesn't explode.
I mean let's say that the population is in stage 1 population growth. It does grow and it seems explosive given that the birth rate is super high. But the death rate is also super high. In stage 2 however, death rate dramatically drops while birth rate stays about the same so the population growth truly becomes explosive at this point. This stage 2 population growth is not wanted on a generation ship. But death rate should be low(or is wanted to be low) and birth rate should be higher at all times on a generation ship(after all the purpose of a generation ship is population growth while in space).
Here are a few things that the people and aliens would have to worry about if they are in a stage 2 population situation(medical care is very reliable on a generation ship):
- Pernicious Anemia(B12 deficiency and Folate deficiency)
- Iron deficiency Anemia
Along with the already existing deaths from illness, injury, old age, etc. they would have to worry about people dying from thirst or nutritional deficiencies. This explosive reproduction and worrying about a high death rate would be less likely to occur if the people are monogamous. This is why I favor monogamy. Plus our society forces monogamy and human polygamy is, at least in developed countries like the US, not allowed by the law.
Case 2: Polygamous
This I am against, not only because it is forced out of human society but for several other reasons.
1) The population growth is going to be explosive and there is going to be a really high death rate because of that(lower than birth rate but still high, too high for a generation ship).
2) Inbreeding is going to be super high. In a monogamous population, you have double the action against inbreeding(so in other words, son can't impregnate mom, sister cannot be impregnated by brother etc. in a monogamous population because not only is the mom against it but so is the dad). In a polygamous population however, to keep inbreeding low, the aliens would need to do maternity and paternity tests(in other words a lot of genetic testing) before a MF pair(male female pair) even thinks about having children and if the MF pair has any kind of genetic similarity whether it be sibling type of similarity(both parents the same) or the father being the same or the mom being the same, they wouldn't allow that pair to breed. But there is 1 problem with this. They would have to test all the moms genetically and all the dads genetically as well because there is a chance that 2 moms or 2 dads could be twins. And identical twin moms and identical twin dads would mean testing of the older people past reproductive age to see if any of them had identical twins.
So polygamy is not good from a sociological perspective(monogamy is the norm nowadays in most places) or from a genetics perspective(lots of testing just to see if the MF pair has the same mom, same dad, same parents(both), or whether the similarity is further back at grandparents and great-grandparents etc.) and just too much testing and thus inbreeding will happen and could lead to a massive population decrease if it continues on like this. It also isn't good from a whole "generation ship is for population growth" perspective.
So I think I should keep my starting number at 5000 and starting male:female ratio at 1:1 and have my humans be monogamous.
But are there any benefits to a polygamous population or is it all just risk after risk after risk? And are there any risks with a monogamous population other than the normal causes of death I described earlier(which isn't that big of a risk on a generation ship)