Why do you conceal your ovulation Ladies?

Why do you conceal your ovulation Ladies?

Once a month a large ripe egg erupts from an ovary and makes its gentle, lazy, slow way down the down the fallopian tubes. Whether it meets its opposite gamete, a tiny overactive sperm fighting its way up the same tube or not is not the subject of these musings. What is a truly amazing thing about this happening amongst a plethora of amazing things to do with human reproduction is that the journey of the egg is done in almost complete secrecy. The women involved will most often not know when it happens, and if there is a man or men involved they will most certainly not know.

It is a remarkable fact that almost alone among females in the animal kingdom and indeed among mammals human females are one of the few animals that conceal estrous or when they are in season. Thus you will know when your female dog (Bitch) is in heat as she will be putting out odoriferous odors and urine trails, her behavior will obviously change and she will become receptive to every dog in the neighborhood. The mare down the road in the paddock will also change doing much the same thing. Dogs and stallions pick up on these cues and are irresistibly drawn to the female in question. Stallions will break down fences and travel for long distances to get to the female as will dogs.

This is the norm in the animal world and seems to make sense as the animals in question are maximizing their chances of a successful coupling at the time when there is every likelihood that sperm will meet egg. Why don’t humans do this? Seems in some ways as though life would be a lot simpler; Sex on certain days of the month with the highest potential to create offspring! Even if it was only the female who knew the days then she could choose to have or not have sex or create the opportunity to have sex with that most favorable male who would give her the best chance of survival and passing on her genes. Seems a no brainer in some ways but we have evolved through natural selection to create quite the opposite scenario. Why?

If you do not believe that we cannot tell the time of ovulation take the fact that The Catholic Church had banned the pill when it was introduced and promoted the Billings method which was a way of females telling by means of temperature measurement, mucous readings and other mysterious way to prevent conception by means of only having sex on the days when you were almost certain not to get pregnant. The Billings and the church spent and huge amounts developing and tweaking the system over many years.  Here is an excerpt from Wikipedia.

Independently in 1953, Dr. John Billings (1918–2007) discovered the relationship between cervical mucus and fertility while assisting the marriage consultant for the Melbourne Catholic Family Welfare Bureau. Some of the couples he worked with had serious reasons to postpone pregnancy, and followed the Catholic Church's teachings of only using natural methods of pregnancy avoidance. While Dr. Billings was familiar with the Calendar and Basal Body Temperature methods, he felt there was a need for something more flexible and more reliable. He embarked on a study of medical literature, and found the mid-19th- and early-20th-century references to cervical mucus and sperm survival. He instructed women using the Rhythm method to avoid intercourse also on all days, and for a few days after, they noticed vaginal discharge. This resulted in a dramatic decrease in unintended pregnancies among these couples.

Whether it works or not is a matter of argument (Suffice to say that most women Catholic or not are using other birth control methods.) The fact that it is so difficult to tell what is going on inside the woman’s body even to the women themselves is the remarkable fact.

But again I ask the question why women (not consciously) keep this matter secret?

Here are some hypotheses they may or may not be true I think there is an amalgam of reasons biology after all is not a science of certainty.

KEEP THAT MALE CLOSE?  A female needs food and protection long term not just on the days when she is fertile. One way is to keep the male guessing than she can enter into a form of long term contract in evolutionary terms. The male feeds and protects the female (And her offspring) in exchange for access rights. While this is a possible solution, it depends on mechanisms to prevent cheating on social rules sufficient to enforce the contract. Things like taboos, religious strictures (Burkha or Chaperoning are good examples)

If ancestral women broadcast a clear message when they were ovulating, à la chimpanzees, then it is likely that ancestral men would have found them sexually appetizing at those times, but pretty much only then, being inclined to look for other sexual partners when their mates were obviously not open for reproductive business. Any such male tendencies would have been facilitated by the fact that other females would be broadcasting their maximum fertility, so a male with a wandering eye wouldn’t have to worry about wasting his reproductive efforts. Male philandering would have been all too easy, at least from the perspective of the male’s identified mate, who presumably preferred that he stay home to guard the cave, bring home the mastodon meat, and help care for the kids.

Mate Guarding   Many species—including our own—engage in what biologists term “mate guarding,” whereby males in particular stay home and alert to defend “their” females’ honor—actually, their own paternity—from the threat posed by other sexually active males. But were ovulation to be clearly signaled, males would be free to abandon their mates, without fear that while gallivanting, they might be cuckolded by other males following the same strategy.

The Shell Game  In short, the Keep Him Guessing Hypothesis suggests that prehistoric women played a sexual shell game on prehistoric men in order to keep them around, 24/7, something likely to be especially useful for a mammal that gives birth to helpless young, who, moreover, take a ridiculously long time to achieve independence. If the male does not know it is his but it most probably is well maybe I better hang around.

 

Infanticide Insurance            It is common in the animal world newly ascendant males (Lions, Rats, some monkeys) kill other male’s offspring. It is part of the way that male can guarantee his genes are projected into the future. Did our ancestors also practice this? Did females develop hidden ovulation or did it developed as a counter measure through natural selection.

Keeping Control          Paternal care through of females and offspring was one of the key components of survival in the brutal world of our ancestors which leads onto monogamy.  Sexual monogamy however is not a key component of survival! In fact in evolutionary terms it seems that women would benefit from coupling with a strong runabout while co habituating with a solid stay at home. Hidden ovulation would facilitate this practice.

Keeping The Peace     Human evolutionary success has depended to a large extent on a harmonious community where everyone works together within a hierarchy of interest. Imagine if you worked at a law firm and a young reproductive female came into the office with the clear signs of estrus. The males in the office roused by her obvious signs (whatever they be) then start fighting over her for the right to copulate. What chaos would ensue, multiply this through society and you can imagine the results!  A great case for hidden ovulation.  

Consciousness    We are conscious beings with whom control and the ability to think things out and through is a distinguishing theme. Lack of control is a dangerous element for us and this includes sexual reproduction. Not for us the wild urges of the bull or the stallion. Although we cannot escape some of these elements. Hidden ovulation aids this inclination.

Competition Avoidance       Females although not as competitive as males none the less live in a competitive world. Inter female rivalry in the past may have extended to the alpha females pressuring younger or weaker rivals into submission or food deprivation. Hidden Ovulation would overcome this to some extent

Lioness Strategy          When lions are in heat they can mate up to a hundred times a day. (Amazing) Some view this as an attempt to keep the lion (male) satisfied and exhausted so he will not mate with any other female. The human female unlike most other animals has a desire for and appreciation of sex on a continual and fulltime arrangement with her partner. (Not as much as lions but then they only go for three days at a time)This guarantees his continual interest, keeps him close to raise the kids and keeps him occupied in guarding her from other males. (Gate keeping). A good counterpart for hidden ovulation.

 

Whatever the cause or most probably causes of hidden evolution it is a fascinating subject and one that we should take an interest in for the betterment of and understanding between and within the sexes.

 

PS: It is also true that ovulation is not completely hidden not on a conscious level anyway for both females and males. Both sex’s behaviors and manner change at the time of estrus. They just do not know it -mostly. But we will leave that for another time.

More Info and a great book : How Women got their curves and other just so stories.   Evolutionary Enigmas D Barash and Judith E Lipton.   Columbia University Press. York.

John Condliffe is doing research for his new book -Sons