sex

Photo of a red-eared slider turtle by Nightryder84. Dr. Thane Wibbels (University of Alabama at Birmingham) is interested in studying how temperature affects the sex of red-eared slider turtle embryos. For humans, the answer is simple: sex chromosomes. You know, the combination of XX means girl and XY means boy. Turtles are not that simple. Temperature is a factor in determining whether the embryo will be male or female. If the eggs are incubated at 78.8 degrees F, the hatchlings will all be male. If they are incubated at 87.8 degrees, they will all be female. As I'm sure you've guessed,…

A recent study published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology presents evidence that altering the sex of just the fat body in heads of fruit flies (Drosophila) causes them to have stress responses similar to the opposite sex. Males and females vary in their response to stress. It turns out that this difference is not unique to mammals as male and female fruit flies also show similar variations. In fruit flies this is thought to be due to differences in the neuronal circuits between the sexes, which may also explain some of the variability…

<I wrote this several years ago as a joke piece for a foster parent group I was on, and I've decided to publish it in case any of you enjoy it.  One of the harsher realities of having 9 kids is that it does cut into your private time, but even more, the psychological heft of foster parenting messes up relationships.  At the same time you desperately need time for one another and restore yourself, you also spend a lot of it obsessing about court dates and outcomes and therapies and meeting your children's needs.  It can be tough to find both mental and physical space for one another - and…

We interrupt this transmission for a puerile message from Medieval Bergen. It was found carved with runes on a stick at the Hanseatic docks. ion silkifuþ a mek en guþormr fuþcllæikir ræist mik en : ion fuþkula ræþr m(e)k (N B434) “John Silkencunt owns me and Guttorm Cuntlicker carved me and John Cuntball reads me” Philologists are not certain as to whether fuþkula, “cuntball”, means clitoris, or a well-padded mons veneris, or “cunt cavern”. All the three mentioned men are historical figures known from other sources, but apparently they are usually referred to there as John Silk, Guttorm…

Certain experiences during my mid-teens a quarter of a century ago left me with this strong Pavlovian reaction to a ladies' perfume called White Linen. It's not very popular any more, and not at all among young women. So imagine my moment of confusion when without warning a whiff of White Linen hits me at George Best airport, making me automatically prick up my ears -- and I find that the wearer is a stout 65ish grandmotherly lady in a floral print dress.

In Current Archaeology #284 (November), Rob Collins has an insightful piece on an intriguing little metal-detector find documented through the Portable Antiquities Scheme. It's a cast copper-alloy erotic miniature sculptural group, apt to excite both a person's scholarly and prurient interest. At first glance, frankly, it just looks like a threesome. Once you've untangled the participants though, you find a man and a woman back to back (as on Yvonne Gilbert's sleeve image for Frankie Goes To Hollywood's 1983 single ”Relax”), emphatically not getting it on together for anatomical reasons, and…

On ERV, Abbie Smith reports on the phenomenal success of the HPV vaccine in Australia.  The vaccine, designed to protect against several types of sexually-transmitted papillomavirus, was first administered to Aussie girls in 2007.  Since then, total prevalence of the virus among young women has dropped from 11.5% to less than 1%—and to 0% among girls who actually got the vaccine.  These girls are also protecting their partners and reducing overall circulation of HPV; infections among young men, who were not even vaccinated, dropped from 12.1 to 2.2 percent. Abbie calls this a "blatant,…

Chances are you already have a strong opinion on this subject.  There's a great deal of noise, mostly but not wholly on the American right about the dangers of fertility decline.  Jonathan Last's book  _What To Expect When No One is Expecting_ and Ross Douthat's recent lament about American women's TFR (total fertility rate - the reason men aren't mentioned is that men don't count in fertility calculations) is down to 1.87 children.  Both writers predict fairly dire outcomes - economic stagnation a la Japan, a benefits crisis as insufficient new workers arrive.  Moreover, for Douthat and…

One of the things that bugs me most in pop-sci and woo-woo science is the obsession with "boosting" the immune system. The immune system is in a constant balancing act - tip it too far one way and even normally harmless bacteria become life-threatening. But tilt it too far in the other direction, and you can end up with things like allergies and autoimmunity. And some pathogens have learned to take advantage of your normal immune responses, meaning that "boosting" your immune system can sometimes do more harm than good. A good case-in-point is a recent paper published in PLoS Pathogens: IL-7…

A lot of readers have emailed to ask why I'm writing a book about sex.  Have I given up writing about energy and environmental issues?  Have I dumped big issues for small ones  - instead of writing about how we should live in this new world, offering suggestions for the best sustainable dildo?  Am I selling out? To those questions I would answer "1. No.  2. Mostly not and 3. I think you have to get paid a LOT more than I get for a book contract to be accused of selling out."  Meanwhile I'm taking my larger framework from the simple idea that sex is the starting point of a lot of our larger…

I know something's amiss when my google news alert returns headlines like these: Why women who lust after Brad Pitt may just fancy his immune system It's His Immune System That You Actually Want to Sleep With The key to male sexiness: A powerful immune system? and my personal favorite Antibodies, Not Hard Bodies: The Real Reason Women Drool Over Brad Pitt These snazy headlines are all pointing to a recent paper in Nature Communications. The paper's methodology is pretty simple: They took 74 Latvian men and immunized them against Hepatitis B. Later, they measured the participants' blood for…

I promise, this will be my last semen post for a while. I've talked about allergy to semen. I've talked about allergens in semen. And I've talked about autoimmunity to semen. All of these are problems, leading to discomfort or infertility. But what if those problems could be leveraged for our benefit? [Source: These drawings were made by Antonie von Leeuwenhoek - the first man to view sperm cells under a microscope] Using the immune system as a contraceptive is not a new idea. In 1899, Karl Landsteiner and Elie Metchnikoff (both of whom would later win Nobel Prizes) independently…

At the risk of seeming like a one-trick pony, and piggybacking on my recent appearance on the Savage Lovecast, I thought I would close the loop on immune reactions to semen. I've already written about allergens being transmitted in semen, and about women having allergies to seminal plasma itself. In the latter case, I say women having allergies not only because the only examples I found were in women, but also because by definition men cannot have allergic reactions to semen. In response to a comment on that post I wrote: If a man did get an immune response, it would probably be called "…

In case anyone landed here after listening to this week's Savage Lovecast, I wanted to point you in the right direction. Please be gentle - that was my first time being interviewed for anything like that, so I was a bit of a nervous wreck. For the uninitiated - a couple of weeks ago on his podcast, Dan Savage fielded a question from a woman that thought a chunk of mushroom managed to make it through her boyfriend's digestive tract untouched and end up in his ejaculate. Dan rightly dismissed this notion, saying that things don't go "from guts to nuts." This is certainly true for solid pieces…

Today is the 100th Anniversary of International Women's Day, founded to celebrate the achievements of women. Founded in Europe to advocate for greater participation of women in the public sphere, International Women's Day focuses heavily on those public sphere accomplishments of women - as political leaders, in education, in activism. Those are important and powerful things, the more important because most of us still have visceral memory of women's past. Consider this Guardian interview with women talking about what has changed in their lifetimes. At the same time that we speak about the…

LOOK at the photograph on the right. Does it show the face of a man or a woman? There's no right answer - the photo has been manipulated to look sexually ambiguous and can be perceived as either. But according to a recent study published in the journal Psychological Science, the sense of touch can influence how you perceive and categorize the face. Last year a team of European psychologists found that bodily movements alter the recollection of emotional memories, and an American group showed that the sense of touch influences social judgements and decisions. The new study adds to the growing…

There's a great scene in the book _Cheaper By the Dozen_ (which had almost nothing to do with the recent movie Steve Martin was in, although there's a fairly good old one) in which Lillian Moller Gilbraith, mother of 12 (11 surviving) is offered by a joking friend as the ideal host for a Planned Parenthood organizational meeting. The PP representative, who has been told that Gilbraith is a model organizer, a professional woman and a leader in her community - but not that she has 11 kids. "Within 15 Miles of Organizational Headquarters!" announces the representative of Planned Parenthood in…

So I was browsing the internet for info on G-protein coupled receptors and ended up finding some interesting facts about sperm. It turns out sperm don't just swim blindly, hoping to randomly bump into eggs. Instead, like bacteria, sperm can sense their chemical environment and adjust their swimming accordingly. Sperm have a sense of smell. The (g-protein coupled) olfactory receptors in our noses that activate our sense of smell were discovered in 1991, an amazing discovery that earned the 2004 Nobel prize for physiology or medicine. The receptors sit on the surface of the cells up high in our…

I've expounded on the principle of crank magnetism. Basically, crank magnetism is the tendency of cranks not to mind the crankery of other cranks, even if the two forms of crankery are mutually exclusive. But it's more than that. It's the tendency of a single crank to be attracted to several forms of crankery. We've seen it in creationists who are also attracted to "alternative medicine," in anti-vaccine loons who are also attracted to alternative medicine and various conspiracy theories, including "9/11 Truth." I've seen it in Holocaust deniers who are also attracted to both "alternative"…

"The males often prefer eating to mating." Apparently, giant panda dudes (Ailuropoda melanoleuca) in captivity would rather sit around and munch on bamboo than get it on with the females. And this is a problem at the Chengdu Panda Breeding and Research Centre, where scientists are urging the pandas to breed, for conservation purposes. What's the answer to this important problem? Panda porn, of course! Pandas are known to be isolated creatures and poor breeders, and in captivity the problem may be exacerbated. Zhihe and his team have tried a number of measures to try to cure the male panda of…