Say it ain’t so, Sir David

wetbaby

I’m sorry to report that Sir David Attenborough done screwed up. He is using his mellifluous voice and awesome reputation to promote the Wet Ape Theory. The show features all the usual suspects: recordings of Elaine Morgan insisting that her story is reasonable, Marc Verhaegen’s pseudoscientific hairsplitting, cartoon versions of evolution by Robert Ardrey and Desmond Morris, and that incessant nonsense of ignoring the whole organism and the existing evidence to argue that, well, this one little piece of our physiology could have evolved in the ocean, therefore we should claim that the whole beast was aquatic, because that is the only way they can now imagine it evolved.

The classic example is Alister Hardy’s initial hypothesis to explain why humans are hairless and have a layer of subcutaneous fat. What other animals have such a combination? Why, whales! They live in the ocean, and have lost most of their hair for better streamlining, and built up fat for insulation, therefore…humans lost their hair to better cut through the water, and evolved subcutaneous fat for heat retention. This is a bad hypothesis, because it ignores so much.

  • We don’t have any other streamlining adaptations, and are actually rather clumsy in the water.

  • Only aquatic mammals that live full time in the water show these adaptations; mammals that live part time in the water tend to have lots of hair.

  • Our “blubber” does a poor job of protecting us from that big heat sink, the ocean. We also lack the circulatory adaptations that make it useful in that function: countercurrent exchangers, arteriovenous anastomoses, that sort of thing.

  • Marine mammals have very little visceral fat; we’ve got loads of it. OK, I’ve got lots. Most of our fat is not distributed in a way to improve insulation.

And most annoyingly, the wet ape proponents simply pretend alternative explanations don’t exist. Hairlessness or reduced body hair, for instance, has evolved independently in several groups: cetaceans, naked mole rats, domesticated pigs, elephants, hippos, etc. So there are different strategies or environmental conditions that can lead to these features, and you can’t simply say all hairless mammals had to have gone through a dolphin-like evolutionary stage, because there are no other situations that can favor hairlessness.

But of course wet ape fanatics do — I’ve seen them seriously suggest that elephants had to have also gone through an aquatic phase.

Attenborough, I’m sorry to say, also takes this blinkered attitude. He closes episode 1 (there are two, I couldn’t bear to listen to the second) of his “waterside ape” series with what he proposes to be a “test” of the aquatic ape theory, which is no such thing. He claims to have new evidence: that there is a known feature of human infants which he predicts would be found in newborn cetaceans, and if confirmed, would both demonstrate the predictive power of the wet ape theory and provide an additional point of confirmation.

That feature is vernix, which is only known in humans. Vernix is the slimy, greasy coat that covers newborn humans, which he wants to claim is an aquatic adaptation, and therefore should be also found in other aquatic mammals. He is able to triumphantly announce that something similar has recently been reported in cetaceans.

But, again, the connection to an aquatic life has not been demonstrated. I don’t even see how vernix helps a mammal thrive in the water; it’s a fetal feature that is lost with the first bath, or is shed within a few days of birth. Vernix has many hypothesized functions for humans:

Vernix caseosa is a white, creamy, naturally occurring biofilm covering the skin of the fetus during the last trimester of pregnancy. Vernix coating on the neonatal skin protects the newborn skin and facilitates extra-uterine adaptation of skin in the first postnatal week if not washed away after birth. It consists of water-containing corneocytes embedded in a lipid matrix. The strategic location of the vernix on the fetal skin surface suggests participation in multiple overlapping functions required at birth, such as barrier to water loss, temperature regulation [the paper later shows a lack of support for this function –pzm], and innate immunity. Vernix seems to perform various integral roles during transition of the fetus from intra-uterine to extra-uterine life. It has also found various interesting diagnostic and prognostic implications in this arena. Thus, it continues to be an intriguing topic of interest among the medical fraternity to understand its detailed biology and function in the fetus and also to put its naturally endowed characteristics to use in the adult population.

Most of those multiple overlapping functions have nothing to do with adaptations for swimming — they are important for a mammal with no insulating layer of hair that is basically born prematurely with relatively few defenses. It is a logical error to imply that sharing a feature with many functions, like vernix, means that two species had to have had a similar ecological history. It makes no sense at all. I am very disappointed that David Attenborough has fallen for such crank nonsense.

I am not being peculiarly fussy, either. Very few people in the evolutionary/anthropological community think the Aquatic Ape is a credible hypothesis. Jim Moore has a very thorough compendium of rebuttals to the hodge-podge of contradictory details that make up the Aquatic Ape Theory; it’s a constant struggle to combat proponents who vomit up all kinds of odd scientific factlets that they claim are supportive of their cherished, much-loved, stupid theory. John Hawks explains why the AAT is pseudoscience. The Guardian has already posted a rejection of Attenborough’s “wishful thinking”. Alice Roberts quickly wrote an excellent response to Attenborough.

The original idea, and certainly Elaine Morgan’s elaboration of it, became an umbrella hypothesis or a “Theory of Everything”; both far too extravagant and too simple an explanation. It attempts to provide a single rationale for a huge range of adaptations – which we know arose at different times in the course of human evolution. Traits such as habitual bipedalism, big brains and language didn’t all appear at once – instead, their emergence is spread over millions of years. It’s nonsense to lump them all together as if they require a single explanation.

Despite the evidence stacked up against the theory, it is strangely tenacious. It has become very elastic, and its proponents will seize hold of any mentions of water, fish or shellfish in human evolution, and any archaeological sites found near coasts, rivers and lakes as supporting evidence. But we must always build our hypotheses on, and test them against, the hard evidence: the fossils, comparative anatomy and physiology, and genetics. In that test, the aquatic ape has failed – again and again.

It is a great shame the BBC recently indulged this implausible theory as it distracts from the emerging story of human evolution that is both more complex and more interesting. Because at the end of the day science is about evidence, not wishful thinking.

Unfortunately, I’m sure this bad idea will emerge again and again. There’s something appealing to the human psyche about one simple explanation of everything, even if that explanation is completely wrong.

Where junk science comes from

Did you know that intelligence is produced by genes that are located on the X chromosome? I didn’t. In fact, I know of a lot of evidence that directly contradicts that absurd idea. So where did that strange claim come from?

Start here. A local television news station in Sacramento reports on Study: Children get their intelligence from their mom. They make a remarkable claim.

Since women carry two X chromosomes — that’s where intelligence genes are located — several studies have found kids are twice as likely to inherit their intelligence from their mom.

Yes, your dad may give you some intelligence genes, but the study says they won’t have an affect on your brain. The genes will only work if they come from your mom because they will go directly to the cerebral cortex. Genes from the father’s side go to the limbic system.

But none of that is true! “Intelligence genes”, whatever they are, are not discrete entities located on just the X chromosome, and it doesn’t make much sense to claim that kids are twice as likely to inherit intelligence from their mothers. Every boy has one X chromosome that they inherited from Mom, and every girl has one X from Mom, and one X from Dad. And what are these “several studies” that did this work? They don’t say.

That second paragraph is pure gibberish. Maternal genes “go” to the cortex, while paternal genes “go” to the limbic system? This makes no sense. You have to watch the report to believe it, though: to evaluate this claim, the reporter calls up his mom to ask her if he got his brains from her, and then goes to a toddler tumbling class to ask random moms if they agree. Science!

You might be wondering, what study actually makes that original claim? They actually have a link to that, but more about that in a moment.

Let’s look in on that hive of blithering mendacity, gossip, and side-boob shots, the Huffington Post. They report on the same “study”, saying Intelligence Gene: Science Proves Moms Are Responsible For Kids’ Smarts. Don’t you just love that phrase, “science proves”, especially when it’s immediately followed by some bogus nonsense?

The genes that carry intelligence are located on the X chromosomes. And since women carry two, it’s more likely that children get their brain power from their mom as opposed to pops.

But while some dads may brush this off, it’s actually extremely unlikely that their intellect has any impact on their kiddos.

“If that same gene is inherited from the father, it is deactivated,” the study reported.

There’s that mysterious the study again. What study? I’ve never seen a study that shows that intelligence is confined to the X chromosome, and such a claim would be bizarre and unlikely anyway. They also give a link, though, and it’s the same source used in the television news story.

Here it is: Did you know that intelligence is inherited from mothers? It’s not a study. It’s a blog post. It contains quite a few references to the scientific literature, but it seems to have muddled up their contents quite a bit. None of them say what the author claims.

For instance, the blog post says “Mother’s genes go directly to the cerebral cortex, those of the father to the limbic system” (so that’s where the news got it…), and cites a couple of imprinting studies done in mice. One of them is even titled “Completion of mouse embryogenesis requires both the maternal and paternal genomes.” If you aren’t up on imprinting, it’s the observation that normal development sometimes requires complementary patterns of gene expression on maternal and paternal chromosomes — that is, on the chromosome you got from Dad, gene A might be turned on while gene B is turned off, while on the chromosome you got from Mom, gene A is off and gene B is on, and that complementation means you’ve still got one active copy of each of A and B.

What about the claim that intelligence genes are on the X chromosome? The author cites a 1972 paper that isn’t a study of any kind, but instead merely proposes the hypothesis that “major genes relating to intelligence are located on the X-chromosome”, largely based on the observation that males have a greater frequency of mental retardation and learning disorders than females. The author also cites another paper that was a review of the database of genetic disorders in OMIM that found that 10% of the genes associated with mental disabilities are linked to the X chromosome.

Both of those facts are true: boys are more likely to suffer mental disabilities, and known genes correlated with those problems are found on the X chromosome. This does not, however, imply the existence of “intelligence genes”, nor does it map intelligence to the X chromosome. What it tells you is that boys are hemizygous for the X chromosome, and that recessive alleles that can cause developmental disorders are more likely to be exposed and phenotypically expressed if a) they’re on the X, and b) they are inherited by a boy. Brains are also particularly sensitive to developmental problems, so generic deficiencies are often going to have cognitive consequences.

Another problem is that the OMIM database is not a complete account of every possible gene and its effect. Some genes are easier to isolate phenotypically…like, if you’ve got a lot of individuals running around who are reliably known to be expressing a deleterious allele in the absence of a complementary wild type allele. Like, you know, some boys. The reason the “intelligence genes” are underrepresented in autosomal chromosomes (that is, non-sex-chromosomes) isn’t because they’re not there, but because they aren’t as obviously expressed or as easily detected. What they’re actually reporting is a bias in the literature: the X chromosome, because of its unusual genetic properties, is more brightly “lit up” than the somewhat more difficult autosomes.

So, basically, the article is all wrong, but coming to a simple, sweeping, fallacious conclusion is more attractive to mass media than a complex, multifactorial, correct conclusion. Who knew?

One more thing. You know how they say you shouldn’t read the comments? I read the comments.

They’re a mess. There are lengthy digressions where people pick over the grammar and spelling of the author, who is not a native English speaker, and people who defend it because the content is so interesting (it isn’t. It’s wrong). But it’s still silly, because it’s written in competent if slightly flawed English, and is perfectly clear. It’s just perfectly wrong.

There are lots of anecdotes about smart moms and dumb moms. These are totally irrelevant to the facts, but that actually is kind of interesting, to see how people are really interested in relating science to their personal lives, even when the science is wrong.

But the worst comments, the very worst, are the ones that take issue with the science. Why? Because those commenters don’t understand the science either, and they take an article that has already mangled the information and mutilate it further. The usual suspects, MRA-types, are outraged, because it has a whiff of feminism.

Highly unlikely. IQ is a product of genetic diversity and since XY is by definition more diverse than XX, intelligence is inherited from the contributor of the Y gene. Men outnumber women by a factor of 6:1 at IQs of 140 and above for this reason. Men, on average, are smarter than women because they have a greater diversity of genetic material to draw upon (fewer redundant systems).

If the original article was merely wrong, that comment is stupidity squared. None of that is true. It is factually false and it is built on a collection of presuppositions and theories that are false.

And then there’s this, which starts off well, pointing out that intelligence is complex and not simply reducible to genes, but then it goes off weirdly into Christian gender roles.

IQ is influenced by many factors – perhaps only half of those actually even being genetic. Clearly our Creator designed males and females to inherit particular types of intelligence. Therefore, the X chromosomes provide the feminine aspects and the Y the male characteristics of mental acuity. We are biologically intended to be balanced and complimentary to each other. There is no disputing this obvious fact.

None of that is true, either!

Let us review.

  • Intelligence is not a product of single genes. A gene does not produce intelligence, an array of genes directly affect brain development, even more genes play necessary supporting roles in brain function, and all gene effects are filtered through and regulated by the environment.

  • Intelligence is not a trait localized to the X chromosome. It is a distributed property of many genes on many chromosomes, and of the environment.

  • Masculinity and femininity are cultural properties. They are not genetic. It is a category error to try to find a genetic basis for skirts vs pants, or manly acuity vs feminine submissiveness.

  • Having a Y chromosome does not increase the genetic diversity of your genome (it’s a desert with a paucity of genes!), nor does “genetic diversity” automatically increase your intelligence.

  • Some humans are idiots.

  • Don’t trust TV news or the Huffington Post or random blogs. You should also be critical of papers published in scientific journals.

I despair of humanity sometimes.

This same “study” is also cited in Good Housekeeping. The disease is spreading.

It’s also in the Wall Street Journal, but cites different sources.

Also, AOL.

And Cosmopolitan.

<curls up, dies>

Please keep Malcolm Roberts, Australia

The last flaming nutter to emerge out of Queensland, Ken Ham, emigrated to the US and is busily exploiting the rubes here, so you get to keep Roberts. We don’t want him. His latest bit of raging stupidity is a speech in which he said:

It is basic. The sun warms the earth’s surface. The surface, by contact, warms the moving, circulating atmosphere. That means the atmosphere cools the surface. How then can the atmosphere warm it? It cannot. That is why their computer models are wrong.

That…that…is shockingly idiotic. I have one question: was Roberts naked when he said that? After all, using his logic, clothes are not a heat source. The only sources of heat are your own body, and external sources like the sun, or a nearby radiator. Therefore, that means that clothes can only cool your body. How can they warm it?

It’s good to know. Winter is coming to Minnesota; last night the temperature dropped below 4°C, and I actually felt a little chilly. I made the mistake of putting on a light jacket, and when I went to bed, snuggling up under the blankets. As the cold season arrives, I think all the climate change deniers ought to follow Malcolm Roberts’ basic logic and strip themselves starkers when we hit -20°C and go play golf. It’s usually sunny and clear when it gets that cold, so they’ll be able to absorb all the energy of the sun unimpeded.

There’s a much more thorough debunking of all of Malcolm Roberts’ lies here.

Twenty questions, twenty answers

Sciencedebate.org sent all the presidential candidates a list of 20 questions about science policy, and most of them have sent in their answers. Gary Johnson didn’t bother. Jill Stein did, but I admit, I didn’t bother reading her answers; I have no intention of voting for her, so I don’t really care, although she did seem to take the questions seriously and had some lengthy answers. I skimmed Trump’s answers (it was easy; they’re short) mainly as a point of comparison with Clinton’s.

Hillary Clinton gives substantial answers to every questions. Sometimes they aren’t very specific, but even there she hints at positive attitudes. For instance, the question on scientific integrity isn’t very good — of course every candidate supports scientific integrity, or at least says so! — and Clinton doesn’t hit on any specific points, but does say she supports “public access to research results and other scientific information”, which is a good thing. But on the question of immigration, she immediately proposes specific bills to assist qualified people in the tech sector. On climate change, she’s going to set ambitious goals.

Generally, my impression was that she (and her staff) made a serious stab at explaining her policy, with enough details that it’s clear she really has plans. This is what I want from a serious candidate.

Trump, on the other hand, had nothing. He’d too frequently wave his hands (his tiny, tiny hands) at “market solutions” providing the answer to everything. He dismissed serious issues: his reply to the question about climate change begins, There is still much that needs to be investigated in the field of “climate change.” Yes, he actually put it in scare quotes. Fuck him.

OK, I decided I wasn’t being fair to Stein, who put almost as much effort into her answers as Clinton did — I can definitely say she’d be a better candidate than Trump. So I looked at some of her longer answers. She lost me with her strategy for protecting biodiversity: Label GMOs, and put a moratorium on new GMOs and pesticides until they are proven safe.. Nope. Sorry. Does she even realize that GMOs are a fantastic tool for reducing reliance on pesticides?

Eyeballs are funny things

This optical illusion is making the rounds. There are twelve black dots located at some of the vertices. Can you seem them all?< ?p>

opticalillusion

You can’t see them all at once, at least: focus on one, and all the others disappear. This is not at all surprising — the central area of maximum resolution in your eye is very tiny, and your peripheral vision simply isn’t very good.

What did intrigue me, though, is that if I focus on a central intersection I can see two dots at once, one to either side of the intersection I’m looking at. However, I can’t simultaneously see two dots on the vertical plane.

I think this means I’d be particularly susceptible to drop bear attacks.

Old Earth creationists are just as ridiculous as Young Earth creationists

The oldest evidence for microbial life has been found in Greenland, with fossilized 3.7 billion year old stromatolites (layered bacterial colonies) found in the rocks. Here’s what they look like:

stroms

And here’s the abstract of the paper:

Biological activity is a major factor in Earth’s chemical cycles, including facilitating CO2 sequestration and providing climate feedbacks. Thus a key question in Earth’s evolution is when did life arise and impact hydrosphere–atmosphere–lithosphere chemical cycles? Until now, evidence for the oldest life on Earth focused on debated stable isotopic signatures of 3,800–3,700 million year (Myr)-old metamorphosed sedimentary rocks and minerals from the Isua supracrustal belt (ISB), southwest Greenland. Here we report evidence for ancient life from a newly exposed outcrop of 3,700-Myr-old metacarbonate rocks in the ISB that contain 1–4-cm-high stromatolites—macroscopically layered structures produced by microbial communities. The ISB stromatolites grew in a shallow marine environment, as indicated by seawater-like rare-earth element plus yttrium trace element signatures of the metacarbonates, and by interlayered detrital sedimentary rocks with cross-lamination and storm-wave generated breccias. The ISB stromatolites predate by 220 Myr the previous most convincing and generally accepted multidisciplinary evidence for oldest life remains in the 3,480-Myr-old Dresser Formation of the Pilbara Craton, Australia. The presence of the ISB stromatolites demonstrates the establishment of shallow marine carbonate production with biotic CO2 sequestration by 3,700 million years ago (Ma), near the start of Earth’s sedimentary record. A sophistication of life by 3,700 Ma is in accord with genetic molecular clock studies placing life’s origin in the Hadean eon (>4,000 Ma).

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