Humans are fairly flexible when it comes to marriage strategies, at least the "normal" ones.
Again, there are types like cuttlefish, where the females lay so many eggs, they can afford to allow fertilization by multiple different donor males, choosing some who are strong, and some who are better at camouflage, but outside of that, humans can be anything from strictly monogamous to purely polyamorous.
Also, to go back to swans for a second, many birds are strictly monogamous. Much like how the game treats marriage now, they do not remarry. In fact, many birds simply stop eating and die if their partner dies. This is because, biologically, many birds have children so dependent upon both parents being there that the whole family will die if either parent dies. A good example can be seen in the March of the Penguins documentary - if the mother for any reason fails to return, (such as being killed by a predator while hunting to restore her fat reserves,) father and child will starve to death waiting for her.
Comparatively, most humans are serially monogamous. (Although it differs in whether they remarry after death, remarry after divorce, or just start cheating after their old relationships grow cold.)
On the other end, a cheetah father does not stick around to care for his children, as the mother is capable of taking care of her young on her own, and as such, a cheetah male can mate with as many different females as he can successfully court.
Not that it isn't hard for a single mother now, but in a world before daycare was common in businesses and there were social welfare programs for mothers, single mothers that didn't have wealth (and weren't disinherited) were staring death in the face. Throughout most of human existence, a single mother might possibly make it, especially thanks to her own family helping, but odds were far, far better for a child if both mother and father were raising the child together. With that said, it's also just possible enough for a single mother to make it to make cheating, from a biological/evolutionary standpoint, worthwhile. A male can have a "real" family, and have a mistress, and possibly raise twice as many children. (A wealthy enough man can afford to have multiple wives/concubines/mistresses, regardless of official laws, and make sure they all are financially capable of surviving.) It's also speculated that apes can show a reason why women have a biological capacity for cheating - when a new alpha male overthrows the old alpha, they tend to kill the children of the old alpha to make the females of the group no longer care for the children of another man, and make them ready to mate again. A female that had cheated with the potential challenger to the throne, however, will put at least enough doubt in the mind of the challenger that they wouldn't automatically kill the female's offspring.
So on the one hand, so long as it fits within the spectrum of what a human is biologically capable of doing, it would make sense that humans could adopt the moral rationale of the society they join. On the other hand, humans are notoriously incapable of all being governed by the same set of marital rules.
Some people are just born to philander no matter what the rules may be, and others will be singlemindedly monogamous even in a society that allows for polygamy. Social mores will have significant impact, but ultimately, MANY people have cheated even in societies whose views of marriage ethics were [ETHIC:SEX_OUTSIDE_WEDLOCK:PUNISH_CAPITAL] and [ETHIC:INFIDELITY:PUNISH_CAPITAL].
Hence, for humanoid styles of reproduction, I would say it is probably best to have a strong innate tendency for some place on the spectrum, and it is moderated to a limited extent by the ethics of the civilization as a whole. If you had it as a scale from 0 to 100 for human reproduction strategies, with 0 being strict (never remarry) monogamy, and 100 being Wilt Chamberlain levels of polyamory, then you might have a random number assigned at birth for their natural tendencies, and then average it out with the number in that spectrum where the society's ethics says they "should" be, and give the natural tendencies a weight of 3 or 4 times the size of the ethics.
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Topic: Where is the Polygamy / Polyandry? (Read 8576 times)