“One of the legends of St. Valentine says that he was a priest arrested by Roman Emperor Claudius II for secretly performing marriages. Claudius wanted to enlarge his army and believed that married men did not make good soldiers, rather like Halsted’s feelings about surgical residents. But Valentine’s Day is about love, and if you remember a romantic gut feeling when you met your significant other, it might have a physiological basis.

It has long been known that Drosophila raised on starch media are more likely to mate with other starch-raised flies, whereas those fed maltose have similar preferences. In a study published online in the November issue of the Proceedings of the National Academy of Sciences, investigators explored the mechanism for this preference by treating flies with antibiotics to sterilize the gut and saw the preferences disappear (Proc. Nad. Acad. Sci. U.S.A. 2010 Nov. 1).

In cultures of untreated flies, the bacterium  L. plantarum was more common in those on starch, and sure enough, when L. plantarum was returned to the sterile groups, the mating preference returned. The best explanation for this is revealed in the significant differences in their sex pheromones. These experiments also support the hologenome theory of evolution wherein the unit of natural selection is the “holobiont,” or combination of organism and its microorganisms, that determines mating preferences.

Mating gets more interesting when you have an organism that can choose between sexual and asexual reproduction, like the rotifer. Biologists say that it’s more advantageous for a rotifer to remain asexual and pass 100% of its genetic information to the next generation. But if the environment changes, rotifers must adapt quickly in order to survive and reproduce with new gene combinations that have an advantage over existing genotypes. So in this new situation, the stressed rotifers, all of which are female, begin sending messages to each other to produce males for the switch to sexual reproduction (Nature 2010 Oct. 13). You can draw your own inference about males not being needed until there’s trouble in the environment.

As far as humans are concerned, you may think you know all about sexual signals, but you’d be surprised by new findings. It’s been known since the 1990s that heterosexual women living together synchronize their menstrual cycles because of pheromones, but when a study of lesbians showed that they do not synchronize, the researchers suspected that semen played a role. In fact, they found ingredients in semen that include mood enhancers like estrone, cortisol, prolactin, oxytocin, and serotonin; a sleep enhancer, melatonin; and of course, sperm, which makes up only 1%-5%. Delivering these compounds into the richly vascularized vagina also turns out to have major salutary effects for the recipient. Female college students having unprotected sex were significantly less depressed than were those whose partners used condoms (Arch. Sex. Behav. 2002;31:289-93). Their better moods were not just a feature of promiscuity, because women using condoms were just as depressed as those practicing total abstinence. The benefits of semen contact also were seen in fewer suicide attempts and better performance on cognition tests.

So there’s a deeper bond between men and women than St. Valentine would have suspected, and now we know there’s a better gift for that day than chocolates.”

That’s it?  That’s why Dr. Greenfield had to resign?  Give me a break.  I thought the article was a great combination of  science and tongue-in-cheek humor.   Evidently poor Greenfield might also have to give up his coveted position as Pres-elect of the College as well.  According to the Retraction Watch post, “that’s under review.”

Now, if I was going to stop here you would probably say, fun read, what’s next?  But I am not going to stop here.  I am going to share the best of the comments posted in response to this article appearing on Retraction Watch.  Are you ready?

Here is from Elmar Veerman who identifies himself as a “European” to be sure we don’t think he is an uptight Red Blooded American:  ”….I have been wondering for years why so many Americans seem to think violence is fine and sex is scary.”

jmrowland agrees, adding “…maybe somebody does need to step down, but it isn’t the author of this article.”

Debbie McKenna got really worked up saying about the article, “…It is so clearly hateful toward women that it is frightening.  Men do not get it.”

A couple of hours later she added, “Would you like it if half of the population, testosterone driven, assumed that women enjoy having that snot-like spew dribbling in or on them.  You have no idea how much the large majority of women actually hate the male body, and are sickened by horn-dogs grope.”  [Horn-dogs grope????, someone please explain.]

Several women piled on telling Debbie she is a bit off base.  Cindy Shannon pointed out that if most women hate the male body and the “snot-like spew,”… then the pregnancy rate would be a whole lot lower.”

Others came to Dr. Greenfield’s defense.  ”S” saying, “I am a surgeon AND a women.  He’s a funny guy, and this was the kind of thing that NPR would feature as a Valentine themed interest piece.”

Anon1mat0 thought it might be good to use the science to develop a new drug, “….that can be made to benefit women with certain forms of depression.”  Adding, that “feminists can use it too, to avoid contact with the icky stuff.”

The comments go on for 50 pages!  In the end, I found myself pondering if Dr. Greenfield made a mistake.  The outcome certainly suggests that publishing a  clever, tongue-in-cheek article about sex in a Surgery trade publication was indeed a mistake.  He should have published it on TDWI (and now we have done that for him.)

Patricia Salber MD, MBA is a Principal in Zolo Health Solutions, and writes on The Doctor Weighs In.