Sex at Dawn

Firstly, it is true that very very few species are sexually monogamous.
Human testes size is generally seen to suggest some pair-bonding with some degree of polygyny and polyandry.

It should also be noted that extra-pair matings in other socially monogamous species do not occur with the blessing of the mate. They are carried out in secret and may be punished eg in the house sparrow and the great reed warbler females will attack secondary females or destroy their eggs. Males mate-guard and punish females.

Though bonobos are represented as highly sexual most of their sexual activity is very brief and non-ejaculatory. It is more similar to chimpanzee 'hugs' and human handshakes.

In chimpanzees (and to a lesser degree in bonobos) females are not having any sex for significant amounts of time between giving birth and between sexual swellings. Maybe for four years in a chimpanzee. In chimpanzees we also get a lot of aggression against females which is mostly connected with sex (as Jane Goodall noted) and the more general aggression of males towards females documented in some groups is seen as conditioning females to accept male sexual advances when the females have their swellings.

But the main difference between these related apes and ourselves is that the females are able to feed themselves and their young independently of direct male provisioning. Once our ancestral females started experiencing the enormous increase in in demands of offspring then they needed access to resources indirectly through males.

We most likely still had groups of related males which young females joined. Infanticide by males of unrelated infants is widespread across species and so we might expect the paternity confusion that mating with all the males would achieve. (And Hrdy's promiscuous females are mating to save the lives of unborn offspring. I don't think we can necessarily presume that they are enjoying the sex. Faking fertile signals is faking.)

But even in chimpanzees and bonobos it is the alpha males who do most of the fertile matings. If 'paternity' is an unknowable thing for males, why would males 'instinctively' treat the offspring of females they have mated with differently from those they have not. Obviously, male behaviour across species has evolved to produce traits that operate for their own reproductive self-interest without conscious knowledge of 'paternity'.

It is quite possible that in groups of related males who depended on each other for group defense there would be an accepted hierarchy including that in relation to fertile matings. Once we bring paternal investment in offspring it is also perfectly possible to expect stronger realtionships between matings and higher status males. And further down the line it is not that hard to imagine not only the exchange of females by males across groups as males evolved to be able to manage those relationships, but also the higher status males monopolizing young females, and young males having to wait longer and to have to prove themselves before they could get a wife/wives.

But the most basic thing that is questionable about this whole scenario of communal sex is who does it benefit the most?
There is a very important aspect of sex that has been there from its beginnings and that is the asymmetry of the sexes. Though the promiscuous male/coy female is certainly way off the mark, what tends to be overlooked is that females (and males in sex-role reversed species)want to mate less than do the males. Males evolve strategies to override female resistance and sexual harassment from males can be very damaging - in some species females are injured or killed such as in seals and sea lions and ducks and dung flies.

Females are not going to benefit from sexual harassment by males in the group and all males encountered. Infanticide may well also be a danger. Mate-guarding is one solution across species. There is one female bird who calls her mate to protect her when she needs to leave the nest to feed and would otherwise be subject to sexual coercion.

Of course mate-guarding is also a problem for females when they do wish to mate with a better quality male than they are with.

So looking at other species where male provisioning of offspring is a factor (socially and including sexually monogamous birds and primates) we have much like we have in humans (secret or punished infidelity)- though in humans there are also many more factors and unique ones too such as group members deciding who mates with whom for the benefit of the group in relation to alliances, inter-group agreements etc.

There is a lot of sexual conflict across species due to males wnating more matings with more partners than is good for the female and her offspring. Of course we would expect human females to want more freedom of mate choice after however many millenia of having their reproduction controlled by males. But we would also expect human males to want even greater sexual opportunities and so arguments for promiscuous female sexuality might be expected from males especially even when it is detrimental to females and their young.

For 'mothers' to be promiscuous we do indeed need all members of society to share in paying for them and their kids. And we would really need to prove that men have no interest in who the father of the kids is, and people no interest in who their biological father is. Communal fathering? It does not exist in any other species.

And females must still be allowed to reject males easily and not be sexually harassed or worse. It's quite possible that if females really do have complete free choice re. sex and have no need to exchange sex for material resources or protection or whatever they will in fact have less sex than currently. After all, there is evidence that female proactive sexual behaviour is still connected to cyclical hormones and much more evidence that a lot of female sexual receptivity is connected to acquiring resources.

The idea that humans are 'naturally' wanting indiscriminate sex is one that returns again and again. In the evolution of sex it is the males who might gain from this, not the females. It therefore becomes possible that it is a particular human male strategy to override the reproductive self-interests of the female just like all those traits males across other species have evolved to override female choice which lead to all the female counter-adaptions that then evolve in the females.

"...because all these behaviors run counter to our evolved nature they will cost us over time. Like celibacy, lifelong sexual monogamy is something we can certainly choose, but it should be an informed decision."

Exactly how is chastity - celibacy is for those offering their sexual desires for some other good (doing without); chastity is choosing to exercise sober (not joyless), moral and conscious limits on ones sexual desires both outside and inside of marriage so that one does not love (or treat) others as objects - and monogamy going to cost us? In societal stability? In genuine self-esteem through, of all things, virtue? In life expectancy because of a decrease in STDs? In learning that we, as a society, can't remain emotionally three years old our entire life grabbing men and women off the shelf like the toys or sugary treats we reached for as children? What are these supposed costs for chastity?

You have got to be smoking bonobo dung or some other crap that alters your sense of reality. Central to being human is the ability to make choices, to exercise ones will. This is just a badly wrapped excuse for those who choose to pretend they have no will and a stern "scientific" warning to those of us who refuse to do so. Can't you come up with anything true? Or real? Or actually useful? I suppose not - it's the effect of whatever you've been smoking.