Sugar and spice and everything nice, too

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I couldn’t resist. Shakespeare’s Sister has a satirical post on the female reproductive tract as a source of gay rays, and evolgen chimes in, noting the similarity of her diagram to the nematode vulva (it’s true—if mammalian vulvas are radiating gayness, nematodes are even more common; Ben Shapiro is probably crawling with hermaphroditic nematodes, all oozing sexual ambiguity all over him). So I had to repost my summary of the evolution of the mammalian vagina, and I want you to look at the diagram of Hox gene expression in the female reproductive tract. It’s like a rainbow! Admittedly, there are no disco balls, pink triangles, or floating Melissa Etheridge CDs, but this is research that has only just begun—as we get more details, we’ll have to sprinkle more symbols in there, and I think Shake’s ideas are excellent suggestions.

Once again, liberal leftist irony stands at the forefront of modern scientific research.

(Oh, and if any guys are feeling left out, I do have an article on penis evolution. All the pictures are in black and white, without any hint of a rainbow.)

Anencephaly and right-wing moralizers

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There’s an important phenomenon in development called neurulation. This is a process that starts with a flat sheet of ectodermal cells, folds them into a tube, and creates our dorsal nervous system. Here’s a simple cross-section of the process in a salamander, but in general outline we humans do pretty much the same thing. Cells move up and inward, and then zipper together along the length of the animal to produce a closed tube.

It’s a seemingly simple event with a great deal of underlying complexity. It requires coordinated changes in the shape of ectodermal cells to drive the changes in tissue shape, and invisible in simple diagrams to the right are all the inductive interactions going on that trigger the differentiation of the tube into a nervous system.

[Read more…]

She’s gone and done it now

The daughter has put up a post with her thoughts on abortion—I swear I have not given her any instruction or even talked about the subject with her, but somehow she has developed roughly the same opinion on it that I have…which means, of course, that the kooks will whine at her. I can’t even imagine what her former peers at high school will say, but it might be explosively fun. There’s a little bit of Mell in that girl.

(Speaking of Mell, you all know that this is the last day of one of my favorite webcomics, Narbonicon, right?)

Genetics of virgin birth in the Komodo dragon

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I’ve just read the article on the parthenogenetic Komodo dragons in Nature, and it’s very cool. They’ve analyzed the genetics of the eggs that have failed to develop (the remainder are expected to hatch in January) and determined that they were definitely produced without the aid of a male.

We analysed the parentage of the eggs and offspring by genetic fingerprinting. In the clutches of both females, we found that all offspring produced in the absence of males were parthenogens: the overall combined clutch genotype reconstructed that of their mother exactly. Although all offspring were homozygous at all loci, they were not identical clones. Parthenogenesis was therefore confirmed by exclusion (clutches had different alleles from potential fathers) and by the fact that the probability of obtaining a clutch of homozygous individuals after sexual reproduction was very low (P<<0.0001). Sungai’s resumption of sexual reproduction confirmed that parthenogenesis was not a fixed reproductive trait (that is, it is facultative) and that asexual reproduction is likely to occur only when necessary.

That line about “all offspring were homozygous at all loci, they were not identical clones” might need a little more explanation. Mama Dragon is heterozygous at some loci, but the meiotic mechanism that produces a diploid egg means that one cleavage (most likely the second meiotic cleavage) was suppressed, so both homologous chromosomes in the resultant ovum were derived from the same replicated DNA strand. They are not clones of the mother, because they are all homozygous while she was heterozygous; they are not identical, because which of each of the paired homologous chromosomes was passed on to an individual is random.

(I’m a little confused by the statement that they offspring are homozygous at all loci, though; that would imply that there was no crossing over at all in meiosis I, which doesn’t sound right. There ought to be reduced heterozygosity but not complete homozygosity, unless reptiles are weirder than I thought.)

The other useful snippet of information is that sex determination in these reptiles is of the WW/WZ type, where the females are the heterogametic sex. Since all of the progeny of parthenogenesis are homozygous, they are all of the homogametic genotype, and therefore male.

Parthenogenesis can also bias the sex ratio: in Varanus species, females have dissimilar chromosomes (Z and W), whereas the combination ZZ produces males10, so the parthenogenetic mechanism can produce only homozygous (ZZ or WW) individuals and therefore no females.

This has theological implications, obviously. We can now understand how a female could give rise to a male by parthenogenesis: Mary Mother of God must have been a heterogametic reptoid. David Icke will be so pleased.


Watts PC, Buley KR, Sanderson S, Boardman W, Ciofi C, Gibson R (2006) Parthenogenesis in Komodo dragons. Nature 444:1021-1022.

But what if I like dandelions?

Maybe we should sic Edward Tufte on ’em—Feministing found some amazing posters that purport to explain everything with the power of overwrought metaphor and cluttered, confusing cartoons. It just draws your eye in with the awesomeness of its arbitrariness.

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So contraception is the source of single-parent families and infanticide? The stalk of divorce leads to the flower of abortion? The leaves of adultery and pre-marital sex use sunlight and carbon dioxide to make the sugar of sexual chaos that is stored in the root of coitus interruptus? Watch out, kids, if you blow on the puffball of euthansia, you’ll spread the seeds of a thousand new sex weeds! Now go in the house and wash the lust and hedonism off your hands.

It just doesn’t make sense.

I realized, though, that anybody can slap random labels on a random diagram to send meaningless messages out. Even me. So here you go, a fun and informative diagram that will help you understand all kinds of curious relationships in the world around you.

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Please, use this information wisely and be sure to let it guide your life…to a brighter, healthier future, rich with the well-earned fruits of ying tong iddle I po.

The full-throated howl of the uncompromising advocate

I’m going to rudely hijack one political issue to make a point about another. I think you’ll quickly figure out what it is.

NARAL has been undermining their own relevance by failing to support pro-choice positions in a misguided attempt to court moderates—basically, as Ezra Klein points out, they’re failing to recognize their role in the political ecosphere. They’re an advocacy group for a specific range of policies, not a politician who has to balance constituencies—they are supposed to be spokespeople for one particular constituency.

…one thing groups like NARAL have a tendency to do is accept vaguely acceptable-sounding or politically popular bills in an effort to remain in the center, believing their group’s moderate credentials — see also their early endorsement of Lincoln Chafee — somehow important. The alternative strategy — practiced by the NRA, among others — would be to wage all-out war on even these minor encroachments, thus fighting to shift the center left.

This strategy of trying to join the center rather than move it is a damaging one. If NARAL were totally dogmatic and absolutist, that would make life much easier on Democrats who could occasionally show their “centrism” by voting against NARAL-opposed legislation that actually doesn’t much matter. Instead, however, to demonstrate independence on choice, Democrats end up supporting much more onerous and repulsive legislation, because just aping NARAL’s priorities line doesn’t win them any points in the media. Elected politicians, after all, often have to remain “in the center.” Independent interest groups, on the other hand, can spend their time trying to redefine what “the center” is. NARAL — and others on the left — should do more to exploit that freedom.

Digby also reiterates this very important point.

I do not think NARAL understands its function anymore. It is not a politician from a conservative district who won with only a few percentage points and needs to pander. It is not a political party that needs to gloss over differences to come to consensus. It is an advocacy organization. Its job is to hold the line and then move the debate their way.

If this is true for NARAL, how much more appropriate is it for the independent voices we look for on blogs? The job of the blogger is not to triangulate and strain to express some hypothetical view of some nebulous ‘moderate’—it’s to state his or her opinion, unmellowed by that fawning desire to appeal to a majority. Our readers are presumably sampling multiple online sources, and what we have to expect is that they will make up their own minds on the basis of those many inputs, and the real arrogance is to pretend that we can read those minds and aspire to represent a majority. We can’t and we don’t. We are nothing but the enabled and accessible voices for nations of one.

I am strongly pro-choice, so much so that my views probably make many other pro-choice people uncomfortable…and that should be OK. I am not trying to stand for a consensus, I am staking out my position.

This is also true for my views on other aspects of the political argument, on science and evolution, and on religion vs. atheism. I simply do not understand why apologists for religion, for instance, think they need to carp at me and tell me to be less radical, to moderate my stance and to quit alienating those hypothetical fence-sitters that they are trying to woo. That’s not my job. My goal is to shift the debate towards my position (without expecting that everyone will adopt my specific views), and I can’t accomplish that by letting the rope go slack and drifting towards someone else’s position.

So, loud and proud, baby. Fight for your ideas, not those that someone else tells you are examples of what the majority wants to hear. Majorities are made of individuals, and the only way we’ll ever get an honest consensus is if everyone is singing out frankly for their own beliefs.

Is this part of the official Cephalopodmas celebration?

Oh! Respectful Insolence uncovers more woo-woo nonsense, a scheme called Global Orgasm that urges everyone to get it on on one particular day.

The intent is that the participants concentrate any thoughts during and after orgasm on peace. The combination of high-energy orgasmic energy combined with mindful intention may have a much greater effect than previous mass meditations and prayers.

The goal is to add so much concentrated and high-energy positive input into the energy field of the Earth that it will reduce the current dangerous levels of aggression and violence throughout the world.

Exactly what is this “high-energy orgasmic energy” that will be injected into the earth’s “energy field”? How does it compare to, for instance, UV from the sun? I think that if you actually measured it, at best what you’d get is a negligible amount of extra heat. It will have exactly the same effect as mass meditations and prayers, i.e., none. Or perhaps we’ll now be told that science can have nothing to say about this business?

Haven’t these people ever heard of mass spawning? I think the prayers of a few copulating people are going to be totally swamped out by the pleas of corals, algae, echinoderms, etc., and if this stuff actually worked, the earth would be 99% ocean and humans would be extinct…and who wants to encourage a practice that urges you to have sex only once a year?

Worst of all, though, these people are usurping my holiday, Cephalopodmas. That’s right, all this woo-woo New Age nonsense is scheduled for 22 December. I say we need to steal it back: go ahead and have sex on Cephalopodmas, but out of appreciation for biodiversity, do something effective and use birth control.

Bad science? It’s OK—just put him in charge of women’s health

Clearly, Bush is not going to drift quietly into oblivion. Majikthise and Feministing report that his administration is appointing a certifiable kook to run the federal program that oversees family planning and reproductive health. His qualifications seem to be that he’s fanatical about abstinence, to the point of making stuff up.

At the Annual Abstinence Leadership Conference in Kansas, Keroack defended abstinence (in an aptly titled talk, “If I Only Had a Brain”) by claiming that sex causes people to go through oxytocin withdrawal which in turn prevents people from bonding in relationships. Seriously.

[Keroack] explained that oxytocin is released during positive social interaction, massage, hugs, “trust” encounters, and sexual intercourse. “It promotes bonding by reducing fear and anxiety in social settings, increasing trust and trustworthiness, reducing stress and pain, and decreasing social aggression,” he said.

But apparently if you’ve had sex with too many people you use up all that oxytocin: “People who have misused their sexual faculty and become bonded to multiple persons will diminish the power of oxytocin to maintain a permanent bond with an individual.” Hear that? Too many sexual partners and you’ll never love again!

I know that oxytocin is thought to have a strong role in bonding, is triggered for secretion in many situations—sex, labor, lactation, etc.—but these claims that you can have permanent depletion of oxytocin levels by too much sex? Never heard of that. I hit the physiology texts in my office; no support. I tried the online databases, and hoo-boy is there a lot of stuff on oxytocin; but nothing I could find to support those claims. Keroack doesn’t seem to have published anything on this subject in the peer-reviewed literature, either—the only source cited for it is something called “A Special Report from the Abstinence Medical Council”. Strangely, the only instances Google turns up of this “Abstinence Medical Council” is as the publisher of this report, and as a part of the Abstinence Clearinghouse, run by Leslee Unruh, unqualified hack (and also organizer of creepy “purity balls”). I think I’m right to suspect the source is ginned-up propaganda for a quack organization.

So there isn’t any evidence for his claims. Is it logical? Oxytocin has complicated and sometimes conflicting effects, so it would be awfully hard to pin down any clear consequences of multiple partners on pair bonding without lots of data, but on the face of it, no, none of what he says makes much sense.

Emotional pain causes our bodies to produce an elevated level of endorphins which in turn lowers the level of oxytocin. Therefore, relationship failure leads to pain which leads to elevated endorphins which leads to lower oxytocin the result of which is a lower ability to bond. Many in this increased state of emotional pain and lower oxytocin seek sex as a substitute for love which inevitably leads to another failed relationship, and so, the cycle continues.

But sex increases oxytocin levels! If he’s postulating that lower oxytocin levels are causal in relationship problems (I’m going with the flow, OK? I don’t buy into the simple chemical explanation of complex relationships myself), then it seems to me that lots of mindless sex would be the corrective prescription.

But then he’s postulating some kind of mysterious depletion or desensitization if you get too much oxytocin. That doesn’t make much sense either, because women are going to get their biggest surges of oxytocin when 1) they go into labor, and 2) they lactate. If ODing on oxytocin diminishes one’s ability to form a permanent bond, then shouldn’t childbirth be a major cause of divorce? There are also oxytocin surges in both men and women during orgasm. Does he also counsel married couples to avoid too much sex? How much is too much? How would he know?

Yeah, he’s waving his hands about interactions between endorphins and oxytocin, but seriously: he’s got no evidence for what he’s claiming, and it doesn’t make sense to claim that brain chemistry on that level senses whether you’ve had sex 10 times with one person or one time each with ten people. He’s making it up as he goes along.

This guy is simply not credible. It looks to me like the Bush administration is trying to throw a sop to the religious right after the defeat of the South Dakota abortion ban by appointing a reliable ideologue with connections to the insane Unruh anti-abortion/abstinence machine to a position where he can interfere with women’s reproductive health. Let’s hope the Democrats will show some spine and squelch this continued nonsense of using fake science to support bad policy.