C-sections haven’t been shown to change human evolution

Everyone and their mother is sending me this story today: C-sections May Be Changing the Course of Evolution.

Rates of caesarean section are increasing in countries like the U.S. and the U.K. and a new study suggests that more and more women need the surgery because of their narrow pelvis size — a trait that evolution would, in theory, have weeded out.

For the paper, published in the journal Proceedings of the National Academy of Sciences, researchers used data from the World Health Organization and other large birth studies and determined that cases where the baby is too big for the birth canal — a.k.a. obstructed birth — have increased from about 30 per 1,000 in the 1960 to 36 per 1,000 today.

I say the paper doesn’t show a causal relationship.

Has the rise in C-sections affected human evolution? This scientist predicts yes.

Human ingenuity increasingly allows us to fight back against “natural selection” and, in effect, influence the path of our own evolution.

Take Cesarean sections, the procedure in which babies are born via surgical incision rather than through the mother’s birth canal. Some form of the procedure has been around for hundreds of years, but only in the past few decades has it become commonplace.

In the US, C-sections now account for 30 percent of all births, according to the Centers for Disease Control and Prevention. But back in 1970, that figure was around 5 percent. So while C-sections have only been widely available to mothers for just a couple of generations, already scientists are speculating that the procedure is affecting human evolution.

This scientist says probably not.

The paper itself argues for obstetric selection in humans.

Compared with other primates, human childbirth is difficult because the fetus is large relative to the maternal pelvic canal. It is a long-standing evolutionary puzzle why the pelvis has not evolved to be wider, thus reducing the risk of obstructed labor. We present a mathematical model that explains the high rates of fetopelvic disproportion by the discrepancy between a wide symmetric phenotype distribution and an asymmetric, “cliff-edged” fitness function. Only weak selection for a large newborn, a narrow pelvis, or both is necessary to account for the high incidence of fetopelvic disproportion. Because the regular use of Caesarean sections has reduced maternal mortality, the model predicts an evolutionary response of fetal or maternal dimensions, increasing the rates of fetopelvic disproportion.

Nah, not buying it.

Actually, they do do what they say: they present a mathematical model of how a disparity between head size and pelvic canal size could hypothetically lead to a selection effect, given a particular frequency of disproportion. They don’t actually measure or observe anything, though. They pull together a number of factors, like the heritability of pelvic and head size, and estimates of the frequency of serious birthing difficulties, etc., all of which show a wide range of reported values, and then put together an abstract series of calculations to show that hey, this could potentially have an effect. That’s it. Don’t panic. We’re not looking at an imminent future of bulbous-headed babies and pencil-hipped women because we’ve removed an important constraint on selection.

Without criticizing their calculations, I have to point out that their assumptions (which to their credit they do note) are faulty. You can’t assume from the frequency of Caesarian sections that there is an equivalent frequency of pelvic diameter – fetal head size disparity. C-sections are an extremely indirect measure of that parameter, one that is prone to all kinds of irrelevant noise…I mean, cultural influences.

Here, for instance, is the frequency of c-sections by country.


Do you think Turkey and Mexico have huge numbers of giant-skulled babies straining to burst out of their slender-boned mommas? Or that in Sweden and the Netherlands they have more pin-headed babies that slip lightly from their mothers’ gargantuan hips?

Or maybe, just maybe, some significant number of c-sections are unnecessary surgeries, and the differences represent nothing but different biases in medical practice? (However, if your doctor advises that you need one, don’t let this fact dissuade you. You might be one of the people who really, really needs a c-section.)

The World Health Organization has reported that in many countries, c-sections are done at an excessive rate, and that above a certain level, c-sections do not reduce negative effects.

Several studies have shown an inverse association between CS rates and maternal and infant mortality at population level in low income countries where large sectors of the population lack access to basic obstetric care. On the other hand, CS rates above a certain limit have not shown additional benefit for the mother or the baby, and some studies have even shown that high CS rates could be linked to negative consequences in maternal and child heath.

Bearing in mind that in 1985 the World Health Organization (WHO) stated: “There is no justification for any region to have CS rates higher than 10-15%”, we set out to update previous published estimates of CS rates worldwide, and calculate the additional number of CS that would be necessary in those countries with low national rates as well as the number of CS in excess in countries in which CS is overused.

This means that c-section frequency is a really bad proxy for a selection pressure. Note also that the United States’ c-section rate is well above the reasonable frequency. That 25% increase in the rate here probably does not represent any significant change in the degree of selection going on.

The math is nice, but it’s poorly rooted in any real biological phenomenon. Although it turns out that making predictions about evolving babies is a good way to get oodles of press.

One nice thing about being a target of hate

I sometimes find myself in very good company.

Jessica Valenti, Lindy West, and…me? Gosh, thanks. I’m flattered.

Also, while it’s not really personal, the Daily Stormer wants to murder people like me. They’ve provided a helpful list for Trump’s right-wing death squads to kill, including:

  1. Lying journalists (where “lying” is defined as opposing Right-Wing Death Squads, I guess)
  2. Political opponents
  3. Human rights activists
  4. Legal immigrants
  5. Liberal university professors (that’s me!)
  6. Filthy sluts (basically, any woman who has sex)
  7. Artists and musicians

Strangely, this list isn’t tagged as “satire”. Instead, it’s got this odd note at the end.

Editor’s note: This is in no way a call for violence or murder. This is a policy position paper in the form of a listicle. The Daily Stormer is opposed to violence, and simply supports the practical implementation of innovative policies which will lead to a great America.

Oh. They’re opposed to violence, it’s just that as a matter of policy they want me executed by roving squads of extra-judicial politically-motivated assassins. Got it. That makes it all better.

But hey, it’s gratifying be classed as an enemy of the oppressive state along with artists and human rights activists and women and all those other decent people. I’ll take it. I wouldn’t want to be a member of a class that had the approval of the Daily Stormer, after all.

Critical thinking is more important now than ever

I just read this masterful summary of “#pizzagate”. It’s appalling. There are people all over the country who think that, because 4chan said so, a slice of pizza is a symbol of pedophilia, and they’ve been harrassing a pizzeria for harboring a child sex ring, in the complete absence of any credible evidence, and in spite of all evidence and reason to the contrary.

What was finally real was Edgar Welch, driving from North Carolina to Washington to rescue sexually abused children he believed were hidden in mysterious tunnels beneath a neighborhood pizza joint.

What was real was Welch — a father, former firefighter and sometime movie actor who was drawn to dark mysteries he found on the Internet — terrifying customers and workers with his assault rifle as he searched Comet Ping Pong, police said. He found no hidden children, no secret chambers, no evidence of a child sex ring run by the failed Democratic candidate for president of the United States, or by her campaign chief, or by the owner of the pizza place.

What was false were the rumors he had read, stories that crisscrossed the globe about a charming little pizza place that features ping-pong tables in its back room.

The story of Pizzagate is about what is fake and what is real. It’s a tale of a scandal that never was, and of a fear that has spread through channels that did not even exist until recently.

Pizzagate — the belief that code words and satanic symbols point to a sordid underground along an ordinary retail strip in the nation’s capital — is possible only because science has produced the most powerful tools ever invented to find and disseminate information.

It reminds me of the McMartin ritual abuse case: it was another set of outrageous stories that people willingly believed. Small children were induced to claim that they’d been sexually molested while at their day care; and then they also told investigators there were secret tunnels under the school, that they’d been taken on round-trips on hot air balloons, that they witnessed animals being sacrificed, that babies were killed and burned, that they saw witches flying on broomsticks. It was absurd. Under the banner of “protect the children!”, though, people accepted these ever-escalating and increasingly outrageous claims, and never considered the possibility that children are extremely suggestible and eager to please.

And now we get the same thing. In this case, though, it is intentionally fueled by malicious trolls on the chans, by conspiracy theorists like Alex Jones, and by masturbatory social media like reddit. We should appreciate that those are not trustworthy sources. They have a history of bad faith argument and ulterior motives. When an accusation is made by a victim, of course you should believe it and investigate it, open to the possibility that it will be found wrong but also that it may be a window into a serious problem…but when the accusation is made by ethically bankrupt professional instigators like 4/8chan, InfoWars, or a random reddit subforum, you should first consider the source, which should lead you to dismiss it as vicious noise.

If users of those media are distressed by the blanket rejection of their pronouncements, the responsibility is theirs to enforce the integrity of their forum and build up some credibility. That won’t happen. A haphazard collection of obsessed users united only by their antipathy to some arbitrary entity and willing to say anything to do harm aren’t going to suddenly find some scruples.

You can now say “Merry Christmas”?

I had no idea of the extent of Obama’s tyranny. Did you know he forbade you from saying “Merry Christmas”? Corey Lewandowski says so, so it must be true.

That’s exactly how Republicans get elected: by telling people lies about their situation, and getting them to believe them. Then, once elected they have to do nothing but declare their own lies false.

Why is Lewandowski still on television? Fox News, I can understand…but shouldn’t a respectable news organization assess the quality of their contributors, and refuse to consider giving air time to people who are demonstrably untrustworthy and dishonest?

oh no michael shermer no

I am simultaneously surprised and not surprised. Michael Shermer tweeted this:

Inez Milholland was a prominent suffragist, so it’s good to acknowledge her. But…

  • He’s using her to promote an article by Christina Hoff Sommers, who is about as much of a feminist as I am a Republican.

  • This article is about how it is inappropriate and weak for feminists to be dismayed about the election of Donald Trump. Don’t worry, girls, the patriarchy doesn’t exist!

  • The article ends by accusing modern feminists of being hyperbolic and harping.

  • You know what’s just not right? To use one feminist to berate a different feminist. We can see right through you guys: your beef is with feminism, period.

  • Insulting modern feminists with slurs like fainting couchers is directly analogous to the insults given to the suffragettes of Milholland’s time.

  • Somehow the only good feminists in some people’s minds are the feminists who died a hundred years ago.

  • It’s telling that the “good feminist” is the beautiful white woman on a white horse wearing white robes. Dead symbols are so much easier to deal with than fractious, real, complicated people.

  • The 1913 march is also known for it’s blatant segregation of black women who wanted to join in — they were sent to the back of the line. Unlike the old feminists he likes, “fainting couchers” now are intersectional.

  • Over 100 women in that march were hospitalized for injuries they received from harassing men. But Shermer accepts Sommers’ claim that there is no patriarchy, women aren’t in any way oppressed?

Just to add arsenic icing to his poison cupcake, his next tweet praises Ben Shapiro. He later declares that he disagrees with Shapiro that transgender men and women are mentally ill, but never walks back the fact that this Shapiro fellow he’s praising is also homophobic, anti-feminist, anti-Muslim, anti-abortion, and doesn’t accept global climate change. But he’s sharp! Just the kind of guy a skeptic would like!

Susan Mazur vs. Carl Zimmer? Really?

There was a Royal Society meeting that I mentioned rather disparagingly — it was on extending the neo-Darwinian evolutionary synthesis, as presented by people who didn’t understand the neo-Darwinian evolutionary synthesis. I wasn’t there, but Carl Zimmer was, and he gave a fair summary of the criticisms of the presentations. Zimmer has always been a first-rate science journalist, and I wish we had a few hundred clones of the guy.

Susan Mazur is someone I’ve described as a journalistic flibbertigibbet who never met a crackpot critic of evolution that she couldn’t fluff up with sensationalist hyperbole. She loved Stuart Pivar’s work. She hyped the Altenberg 16 meeting. She doesn’t seem to understand any biology at all, and is not interested in learning any — she seems more concerned with getting the approval of ‘controversial’ flakes, in the forlorn hope of being the first to report on radical breakthroughs.

Mazur also reported on the Royal Society meeting. Or at least, as Larry Moran explains, she reported extensively on the presence of Carl Zimmer at the meetings. You want to see white-hot professional jealousy screamingly displayed, go read her post. It’s embarrassing. Would you believe she wrote a whole book, Royal Society: The Public Evolution Summit, about the meeting before the meeting? Now she’s bitter that she can’t get her stories about the Paradigm Shift she predicted would take place published, and she’s particularly bitter that mainstream, consensus critics of her imaginary revolution presented at the meeting. How dare they ruin her innovative auto-da-fé?

Somewhat surprisingly, she’s particularly irate with all the Templeton-funded scientists who presented there.

Ten of the 26 presenters were part of the John Templeton Foundation-funded Extended Synthesis project. Templeton is known for its pairing of science and religion. And as the talks proceeded, it appeared to some in the room that the JTF-funded scientists had both compromised their work and retarded science by accepting the foundation’s easy money.

That sounds like something I’d say, except that her complaint is that those scientists, by accepting the mediocre science of modern evolutionary theory, were acting contrary to its [Templeton’s] “spiritual” mission.. I know, we’re in the bizarro world.

Mazur only found a few things she like about the meeting, and of course they were the weirdest, farthest-out proponents of the wrongest ideas: James Shapiro and Denis Noble.

James Shapiro, the other bright spot of the RS meeting, highlighted themes from his book, Evolution: A View from the 21st Century, regarding symbiosis and hybridization and waded into the water on viruses, talking about their role in formation of the eye and the placenta. I addressed a question to Jim Shapiro about stem-loop RNAs (viruses), which Shapiro said he was “challenged by.”

The other notable conference news was Denis Noble citing the embryo geometry paper of Stuart Pivar, who was seated in the room between wife Larimore and co-author David Edelman and elegantly dressed in a black velvet jacket for the occasion. Pivar has faced fierce criticism in the past regarding his evolutionary perspective, particularly from the PZ Myers pack, and so welcomed Denis Noble’s recent invitation to publish in Progress in Biophysics and Molecular Biology, one of the journals Noble co-edits. Noble is also listed on the “advisory panel” for Pivar’s new web page: urform.org.

With so much exciting evolutionary science now openly accessible online, it is disappointing and most peculiar, that this meeting about supposedly “new trends” squandered an important opportunity to deliver that to the public and instead served largely to reinforce standard thinking on evolution.

Well hello, pack! You got a shout-out!

You know, if Carl Zimmer were writing this kind of summary, he’d explain what stem-loop viruses are, maybe actually say what challenging question he asked, and he’d note something other than Pivar’s choice of a jacket. This is exactly why Mazur is such a horrible writer about biology.

But just for an example of really bad journalism, read Mazur’s 2000 word hate-rant against Carl Zimmer. Be like Carl. Don’t be like Susan.

My week of pain has begun

Students get to suffer through final exams next week. This week piles of work come due and get handed to me, and I am committing to getting them all graded as they come in. I’ve got different classes handing in stuff on Tuesday, Wednesday, and Thursday, so that means every day has a fresh bolus of essays and lab reports pouring in, and if I don’t get them done that day, I fall farther and farther behind.

We’re also doing phone interviews for our current cell biology search. Eight candidates. One hour each. Do the math.

In the midst of all this, I still have classes to teach.

At least next week looks like paradise in comparison: I’m only giving one final exam on Thursday, and it’s optional, so the whole class won’t be taking it.

Unfortunately, what I’ve got scheduled for next week is to start prepping for spring term classes, since I’m teaching a brand new course in ecological developmental biology. I’ll also have to start raising fly stocks for genetics. And getting my lab in shape for a new project we’re starting.

You are not entitled to your opinion

I once had an indignant student tell me that what I was teaching in class about evolution was “just my opinion” and that they had a different opinion, and therefore they were justified in rejecting a major chunk of the class subject matter. I think I just gave them the standard line — you are allowed to believe what you want, but in this class, you have to demonstrate an understanding of the science, even if you disagree with it — but over the years, I’ve evolved towards a somewhat harder stance. You don’t get to declare whatever you dislike to be an opinion. You don’t get to regard your opinions as somehow sacrosanct. I am going to give you the information that shows your opinion is wrong, and the purpose of my teaching is to get you to change your opinions to something more productive and correct, and more in line with reality. Those kinds of opinions should not survive an encounter with the facts.

So I’m already in agreement with this philosophical position that “No, you’re not entitled to your opinion”. There are different kinds of opinions, and this is a very useful explanation.

Plato distinguished between opinion or common belief (doxa) and certain knowledge, and that’s still a workable distinction today: unlike “1+1=2” or “there are no square circles,” an opinion has a degree of subjectivity and uncertainty to it. But “opinion” ranges from tastes or preferences, through views about questions that concern most people such as prudence or politics, to views grounded in technical expertise, such as legal or scientific opinions.

You can’t really argue about the first kind of opinion. I’d be silly to insist that you’re wrong to think strawberry ice cream is better than chocolate. The problem is that sometimes we implicitly seem to take opinions of the second and even the third sort to be unarguable in the way questions of taste are. Perhaps that’s one reason (no doubt there are others) why enthusiastic amateurs think they’re entitled to disagree with climate scientists and immunologists and have their views “respected.”

I have to agree. The statements “I like chocolate ice cream” and “I think the earth is 6000 years old” are both opinions all right, in a shallow and colloquial sense, but they are qualitatively different. That I respect your right to have your own taste in ice cream should not imply that I also grant you the privilege to ignore our shared reality. The author, Patrick Stokes, explains all this with examples from anti-vaxxers and climate change deniers, but it’s true for lots of phenomena.

It’s the core of the Answers in Genesis claim that they are using the same facts, but different views (they prefer to use the word “worldviews” over “opinions”, but it’s the same thing). They think they’re entitled to their own opinions and interpretations of reality, and that they can look at a Cretaceous fossil and declare that, in their opinion, that dinosaur died in the Great Flood in 2304BC…they certainly have the right to say that, but they go further and demand that you respect that opinion as equally valid to that of a scientist.

We also see it in politics. Look at this claim by Scottie Nell Hughes:

“On one hand, I hear half the media saying that these are lies. But on the other half, there are many people that go ‘No it’s true,’” Hughes said. “And so one thing that has been interesting this entire campaign season to watch, is that people who say ‘facts are facts,’— they’re not really facts.”

“Everybody has a way—It’s kind of like looking at ratings, or looking at a glass of half-full water. Everybody has a way of interpreting them to be the truth or not true. There’s no such thing, unfortunately, anymore, as facts,” she added.

I’m pretty sure Hughes would argue that the facts show that she is a mammalian humanoid, with records to show that she was born to fully human parents, but it is my opinion that she, and all the other Trump surrogates, are actually alien reptoids who hatched from eggs incubated in a dungheap. And apparently, she’d agree that her facts are useless and my interpretation is perfectly valid.

Unless, of course, we can agree that some opinions are falsifiable.