Textbook finesse:
Usually the word finesse refers to skill and subtlety, whether completely honest or not. Technically in cards it is a matter of playing a lower card when a higher card is held hoping that an intervening card will not be played. All I know is that my best friend from grammar school, Billy, was a master at it. He could do it twice in a row and I swear I have seen him do it three times in a row. I don’t think I have ever done it.
In the game of bridge you are partners with the person sitting opposite and vying with those to left and right. Bill’s technique involved guessing where a high card was and then playing a lower card after the high card had not been played. If that is muddled, so is my thinking. Although I never learned how to do it, I did through long and bitter, actually quite fun, experience, get a sense of it happening. Basically the feeling is that in order to finesse a point, you introduce your argument after the opportunity to counter it has already passed.
While I was at the Orlando meeting of the American Society of Reproductive Medicine in 2011 I asked about a standard textbook on infertility and was referred to the relevant section of Clinical Gynecologic Endocrinology and Infertility, Marc A. Fritz and Leon Sperof, Lippincott, Williams and Wilkins, Philadelphia, 2011.
Technically speaking, infertility is divided between pre-zygotic and post-zygotic infertility. As I sometimes say, that baffles me a bit since generations cycle and what may be pre for one generation may be post for another, but there it is. That’s the first distinction. And I can say right off the bat that when you create a computer program to model infertility you must be quite specific about which type you are interested in. It does make a difference.
And my own efforts strongly suggest that both mechanisms are in effect in humans. Go back to the notes I put together for the Orlando meeting and you will see that for mice and humans teeming without restriction, the population rises, falls, rises again and then crashes. To me that means there must be two mechanisms; the dynamics would be very hard to account for otherwise. And the notion that two parallel systems evolve seems rather far fetched. It seems intuitively that two mechanisms would be different, and pre- and post-zygotic would fill that bill.
Eagerly did I gaze into the introduction to the section for the words, “There is no pre-zygotic infertility in humans.” The words are not there. Instead there are chapters on female factors in infertility and a chapter on male factors, but that finesses the question. Had the statement been made, I would have had the opportunity to say, “Au contraire, I have evidence to show that there is pre-zygotic infertility in humans.” And evidence I do have, which I shall get into shape to present you with some day.
But I cannot object to a statement that has not been made. Simply dividing the chapters leaves no place where the statement would be required.
It kind of reminds me of the fact that the NIH is where the government spends your money on genetics and the CDC is where the government spends your money on infertility; and the two institutions do not talk to each other. Hence there is no field of the genetics of infertility.
I should give them their due of course. It seems that pre-zygotic infertility saturates out rather quickly. By the time you are out to 10th cousin, it doesn’t matter how distant the relationship is. Horses and donkeys have been different species for a very long time, yet their mutual primary infertility is not all that low. So it is reasonable to think that among humans primary infertility is no issue – reasonable, but from my own evidence not true.
There were some interesting points in the textbook. Right off the bat they say that contrary to popular belief, there is no increase in infertility. Then they turn right around and talk about the falling number of babies. Indeed there are many causes of infertility that they can point out among those who come to a doctor asking for help with infertility. But even there they find a substantial proportion of couples for whom no cause can be suggested.
There is a condition called “endometriosis.” Women who have it are very likely to be infertile. And the abnormal tissue has epigenetic changes. Since it seems to me that infertility and epigenetic changes go together I tried to figure out a way to hook them into endometriosis, the cause of which is also mysterious, but I can come up with nothing.
At the meeting it became clear that the reason that there is no world epidemic of low sperm counts is that the UN keeps changing the definition of low sperm count to keep most of us in the normal range. The counts are lower but the low end of normal keeps getting lower too. This is quite different from things like hypertension, diabetes and high cholesterol where they change the numbers so as to put more people outside the normal range. Funny old world. Anyway, I took away nothing new about sperm counts.
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