An excellent blend of adaptations. Many fathers insures genetic variation. And a stable relationship insures young survive to adulthood. Viola! Survival!

One of the main problems with the implied comparison between Damselfish and humans is that, because Damselfish lay eggs that are fertilized outside the mother's body, the concept of cuckoldry doesn't really apply. Cuckoldry can (and does) happen frequently in humans, because the egg is fertilized and matures inside the mother's body. Concealed ovulation only adds to the human female's ability to deceive a male into thinking that a child is his, when it is not.

I realize that there are monogamous species of animals out there (although, it should be noted, that the 'mating season' definition means that animal monogamy is serial monogamy), but I honestly don't think humans are one of them.

Why am I thinking about Troy McClure's fish fetish?

So you're defending monogamy now?

Unfortunately, humans don't have a mating season. I wish we did. Think how much more productive I could be if I weren't so easily distracted by sex, but for a couple weeks a year.

This kind of evolutionary argument for human behaviour is deeply flawed. These studies on mating behaviour of animals are very interesting, and how different animals maximise their evolutionary potential via various strategies of mating is very enlightening to the processes of evolution.
However, human behaviours are a product such a complex set of interacting environmental and genetic inputs. I would suggest that there are many things our ancestors did that I feel no urge to do.
Ultimately, trying to detangle this web, especially with such a complex trait as human behaviour, or sexual desires, is going to be a fruitless and pointless task.
Does it matter if an urge or desire I feel is genetic or somehow from my environment? If it is not genetic is it less valid? I don't think it should be.

My point is, we know how people are now, some don't want to be monogamous, some do. Just be comfortable with who you are and don't make promises you can't keep.

It's a good thing I don't plan on having children. Now I don't have to remain monogamous. Except that I remain that way because I have a strong bond with my partner, and the risk of STDs is enough to keep me from sleeping around.

This is why looking to the animal kingdom for what is "natural" or "normal" has little bearing on what actually works in an honest and communicative relationship. Please, go find me a study that shows a species where a mating pair brings back a third for mutual gratification for all parties involved? Or how about a species that dresses up as other species to turn themselves or others on? There are loads of things that work for humans that aren't reflected in the animal kingdom and lots of things that work in the animal kingdom that won't fly with humans.

It's good to see that in nature, all manner of relationships exist, but just as a mormon cannot justify a patriarchal polygamous marriage as "the answer" because it's relatively common in the animal kingdom, nor do we throw up our hands and say, "well, monogamous birds cheat on each other so all bets are off for monogamy"

Once again, Dan, I would plead with you, If you won't accept "homosexuality isn't natural" as meaning anything at all (besides being downright wrong it's not an argument against gay marriage) neither should you continue to spout this nonsense about how "unnatural" monogamy is. If it works for a couple, great. If people mutually agree to some other arrangement, great as well.

@9+10, yes you are right, this is more within the context that Dan likes evolutionary explanations for polygamy/non-mongamy, and it is a subject that has come up before.

As a geneticist, I would (and did) question the fact that these studies are in any way applicable to humans. However, I am aware that I am inherently distrustful of these behavioural studies, and that the blog itself was well written and fair in the way it dealt with the comparison with humans.