I saw this on Discovery a long time ago and for some reason thought of it recently. It was about relating mate fidelity to testicle size. Gorillas, ironically, have the least effective homunculous factory in the ape family. Chimps, stranger still, are the most bulbous. Human men fall somewhere in the middle. Gorillas are also the loyalest of mates, and chimps the least, "monogamy" non-existent in their vocublary -- and anything else for that matter, well not counting sign language, wait that's gorillas. Going on, Gorillas then, who recruit less little-versions of themselves with them for a rump in the jungle then chimps, must be able to have multiple sessions with one partner to ensure pregnancy, while the chimp is a one shot champ. The argument goes that human males desire monogomy but are prone to infidelity because, having a median soldier count, they can sometimes sack -- pun intended -- the city in one raid, but need diplomacy, in the form of gifts, flowers, and displays of wealth, to gaurantee entry into the city walls. (I may have failed on two accounts here, 1) being funny and 2) explaining this well. The analogy makes this sound like it's about the effectiveness of persistent wooing vs. one-night stands to get to bed, when really the point is partners have sex -- yes, let's put aside the euphimisms for a moment -- more often than singles with multiple partners, thus increasing the chance of fertilization. The mid-sized human is just big enough to get it done in one try sometimes, but needs something stable as a guarantee.)
Now there seem to be some problems with the soundness of the argument itself, which isn't my main issue in writing about it, I'm more concerned about what it implies, but I think it's worth discussing. Firstly, there seems something fishy -- no pun intended, no really -- about its statistical assumptions. All things being equal, chance of fertilization has nothing to do with the diversity of partners; it doesn't matter if you have sex 1,000 times with one partner or sex once with 1,000 different people, chances of fertilization is the same, just like the danger is equal playing russian roulet twice with one revolver or two different guns. Assuming that both apes can have sex as often as they want, neither the chimps promiscuity nor the gorilla's monogamy alone is advantageous.
But let's get back to realities from statistical ideals, 1) it is most likely across most species coupled males have sex more often then their bachelor cousins and 2) commitment to a partner undermines a male's ability to produce progeny during his mate's pregnancy. The argument could be made then a chimp's more generous delivery produced no natural selection for chimp monogamy. While similarly behaving bachelor gorillas were selected against because of less potent jungle juice (I'm running out of slang here), monogamous gorillas had sex more and hence more had progeny, but with the cost of not being able to sauce the pan with a bun already in the oven. But again, this has nothing to do with oversized loads. Because chimps and gorillas can't -- or at least don't -- inter-mate, the pressure of natural selection in terms of fertilization is a competition within the species, not between them. That means, whatever is the most advantageous stategy, regardless of sperm count, should win out.
In other words, if the pro of more sex within a couple outweighs the cost of a 9-month loss of nookie, then that strategy should prevail within the species whether or not the fertility between them differs. Which copulation strategy will produce the most progeny is independent from sperm count; a higher sperm count will always lead to more children for any strategy, but no strategy will have an inverse relationship to sperm count. It seems then that the best strategy, in either species, would be to stay with one mate until she is pregnant, or it is clear that she can't get pregnant, and move on -- and way back in the day that seemed to be the case in some ancient cultures, though, as I'll explain later, if there is any actual connection between these practices' effectiveness and their existence, we have thankfully moved beyond them.
Secondly, the process of describing each structure of the organism as arriving from natural selection is, not just overused, but often just false (cf. The Dialectic Biologist, Levins and Lewontin). Take the vestigle organ: the appendix does not function in the body as some evolutionary optimum; it's neutral selection value has let it trail on (literally) for thousands of years, shrinking without selection's refinement. It is very possible that gorillas developed monogamy for completely different reasons -- perhaps the need of a male's presence to protect off spring -- which in turn made larger cojones vestigial. This is actually the negative version of the argument being critiqued; instead of the sperm count causing x, x causes the sperm count. While difference in sperm count should not effect selection of the most effective copulation strategy, selection for the most effective copulation strategy can render high sperm count less important! So maybe the discovery of monogamy is actually the cutting edge of copulation evolution, rendering over-powered testes passé -- the proverbial cannon downgrades with only the love bug to swat.
However -- though I've severely digressed -- it is the application of evolutionary history to either support or dissuade social practices that I take issue with. Whether intended or not, describing the impulse to cheat as some evolutionarily crafted mechanism to insure we pass on our seed just gives a group of already irresponsible men excuses they don't deserve. And for no good reason. What we used to do has nothing to do with what we should, I'm not saying anything new, just look up "naturalistic fallacy" -- spelled with an "f" not a "ph." When these arguments appeal to nature to extenuate moral failures, implicitly in this case, they aren't really taking about "what we do naturally" because, as an explanation, that would be a truism, like saying, "I cheat because I cheated." Nor can it be, "there are inherent impulses in us that cause us to do wrong" because it is equally guilty of the same truism. The appeal to nature really means something like, "there is something installed in us before birth as the result of million of years of evolution which helped us survive and still operates on us now." That may be true, but, again, there's no reason to hold those instincts in any more reverence than our societal structures against them. Humans I think are at the bottom of the endangered species list, so nix on the survival need. Are they mitigating because they predate thought? Old isn't better or more fundamental for any reason in particular. So although this appeal sounds sexy, really it doesn't make our instincts any more holy then any other product our circumstance of being human, of which the need for monogamy is a part. In essence, appealing to ball size as an excuse for infidelity is no better than explaining, "I wanted to get laid."
The Discovery show seemed to give reason to feel better about having cheated or the impulse to cheat: "my nuts made me do it." But when you really look at the reason, besides the reasoning being flawed, it sounds as silly as, "well, monkeys do it." There may be some explanatory power in the theory -- again, despite what I see as flaws -- as to why we may have instincts against the moral imperatives of our culture. But the attractiveness of these explanations, especially in talking about the "natural" human, is rarely in what they can explain about instincts, but what instincts can excuse in our behavior, an outlook which is not only false, but dangerous.
