> There are plenty of species

How much in percents is that "plenty"?

It's easy to toss qualifications, it's much harder to reasonably quantify what we research. I don't agree it's "plenty of species" (Edit: of course, in a sense that it's useful for a discussion argument, as in "majority", certainly not in a sense "an example can't be found" of course it can).

What percentage of species, or what percentage of individuals in a species? I don't know about the former, but in the latter case there are several species which are documented to form monogamous relationships with no extra-pair copulations (EPCs). That wikipedia page cites a couple of studies:

Anderson, D. J. and P. T. Boag. 2006. No extra-pair fertilization observed in Nazca Booby (Sula granti) broods. Wilson Journal of Ornithology 118:244-247.

Moreno, J., L. Boto, J. A. Fargallo, A. de Leon, and J. Potti. 2000. Absence of extra-pair fertilisations in the Chinstrap Penguin Pygoscelis antarctica. Journal of Avian Biology 31:580-583.

Lifjeld, J. T., A. M. A. Harding, F. Mehlum, and T. Oigarden. 2005. No evidence of extra-pair paternity in the Little Auk Alle alle. Journal of Avian Biology 36:484-487.

Just three kinds of birds?

Nazca Booby, Chinstrap Penguin, Little auk.

Those were just the studies I could find offhand of monogamous species with no EPCs. If you include EPCs, about 90% of birds are socially monogamous[1]. According to [2] ~25% of those species are genetically monogamous (i.e. no EPCs). Though I should mention that genetic monogamy is a pretty high bar, which humans do not pass by a long shot. Is this sufficient evidence for you?

[1]Lack, D. 1968. Ecological Adaptations for Breeding in Birds. Methuen and Company, London.

[2]Griffith, S. C. , I. P F. Owens , and K. A. Thuman . 2002. Extra-pair paternity in birds: A review of interspecific variation and adaptive function. Molecular Ecology 11:2195–2212.

> Is this sufficient evidence for you?

Sufficient if we just consider birds, of course. But what do we discuss here? It started with the

"There are plenty of species which are well documented to have monogamous relationships"

claim and all I see is birds and birds.

Edit: thanks for finally answering below my question "how much in percents is that "plenty of species"?" Your answer is "90% of birds." The rest of discussion would have been unnecessary, especially quoting some three specific birds as the answer. I also agree with yours "the average sexual behaviors across all species doesn't give you much insight."

I chose birds because it's a taxa I know well and I knew to be largely monogamous. I've shown 90% of birds are socially monogamous, and 1/6 of vertebrate species are birds, so at least 15% of all vertebrates are monogamous, and that's plenty enough for me. If you want more exact numbers feel free to look for them yourselves, but I think I've given you a pretty good starting place. For the record, I doubt you'll find anything in the existing literature which attempts to give exact percentages, mostly because it's a rather useless figure. Taking averages over species assigns equal weight to some obscure insect species on one particular island with only a couple hundred individuals to a species with a global distribution and billions of individuals. And even once you get that number, the average sexual behaviors across all species doesn't give you much insight.

0.01% would be plenty in this context.

Remember this is not a popularity contest and there are a lot of species out there. Why does behavior X happen is not asking what happens the other 99.99% of the time.

> 0.01% would be plenty in this context.

Why? What is being proved, unless we talk about majority? So we are able to find some animals that are monogamous and not violent? What then?

Like in the article, tossing "plenty" and "many" actually doesn't help for anything more than creating illusion that the behavior we like is somehow "supported" by nature.

It's not problem analyzing some behavior, the problem is unsupported "plenty" and "many."

Saying N% of species engaged in a behavior would be a meaningless statement. There are probably a few billion (real, not discovered) insect species. We will probably never discover and catalog them all genetically unless we invent nanotech before the big extinction. Insects are not relevant to this discussion; neither are mollusks, or really dumb fish, or worms, etc.. So scoping this to "a plurality of species that have some intelligence" is somewhat appropriate.

That said, this whole thread is nothing but people trying to anthropomorphize nature, so that they can pretend it's more cuddly than it actually is. There is no chemical for morality secreted by all species. There is no evolution for empathy. These are things humans create through their own intelligence, and no amount of anthropomorophized behavior will make that not the case.

> So scoping this to "a plurality of species that have some intelligence" is somewhat appropriate.

And then we come to our nearest relatives (bonobos, chimps) being both promiscuous and ready to jump on the same sex and to use that behavior as a bonding ritual.

> people trying to anthropomorphize nature, so that they can pretend it's more cuddly than it actually is

Exactly, Disney would certainly not approve Fark squirrel:

https://img.fark.net/images/mw/X.jpg

>And then we come to our nearest relatives (bonobos, chimps) being both promiscuous and ready to jump on the same sex and to use that behavior as a bonding ritual.

They also commit cannibalism, rape, murder, bullying. You can't get any morality or moral arguments out of nature.

> You can't get any morality or moral arguments out of nature.

Specifically, you can't use pure existence of some acts in the nature as an excuse or confirmation for validity of any human acts.

Still studying the nature and the dynamics of living beings can actually help us humans more understanding our own actions, it gives us a good context as we're also animals, even if that thought isn't pleasing to everybody.

Not to derail, but...

You’re presupposing a specific morality, and then rejecting other forms of morality on that basis. Alternatives are going to by definition be different. So, you need another way to judge them.

There is a biological basis for X behavior in several species. This is plenty to start looking for similarity’s and root causes.

Think of it in these terms, if one species of poisonous animal is brightly colored that says little. If several are brightly colored that's more significant.

Edit: In math you only need one counter example to disprove a theory. In science a few is generally enough.