Paleo-walkabout

The classic account of the origins of Native Americans is that during the last Ice Age, the seas were lower, and what is now the floor of the Bering Sea was a broad, flat valley.  This allowed people to cross from Siberia into Alaska, and when the weather warmed and the seas rose, this cut off the "land bridge" and left the migrants North Americans for good.

Some cool new research out of the University of Copenhagen has shown that this story is a vast oversimplification, and that what actually happened is considerably more complex than a one-way hike from west to east.

In a paper in Nature called "The Population History of Northeastern Siberia Since the Pleistocene," by lead author Martin Sikora and no less than 53 co-authors, we find out that there wasn't just a single wave of migrants, and there was considerable back-and-forth, even after the seas flooded in and cut Alaska off from Siberia.  Sikora's team analyzed the DNA extracted from teeth from 34 different burials, from Finland all the way across to northeastern Siberia, and compared this to genetic material from Native American populations in northwestern North America.

What Sikora found is that there were several surges of migration across the "Bering Land Bridge," starting over thirty thousand years ago.  Each new wave of travelers mixed and mated with the preceding group of settlers -- and then some of them went back the other direction, settling in northeastern Siberia (where many of their descendants still live).  The authors write:

Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood.  Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago.  We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of ‘Ancient North Siberians’ who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to ‘Ancient Palaeo-Siberians’ who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name ‘Neo-Siberians’, and from whom many contemporary Siberians are descended.  Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.

This study adds to some earlier work, published late last year, that found that the movement of those migrants once they got to North America was equally complex, going in (at least) three waves as they colonized the continent southward and eastward, with the second wave carrying people all the way to Tierra del Fuego.  This blows a neat hole into the idea that "Native American" is some kind of monolithic race of people all of whom are closely related -- which anyone who knows about the very disparate groups of Native American languages would find completely unbelievable anyhow.

[Image licensed under the Creative Commons 맛좋은망고, Langs N.Amer, CC BY-SA 4.0]

So as usual, reality turns out to be both more complicated and more interesting than the accounts you usually hear.  The walkabout taken by the ancestors of the indigenous inhabitants of the Americas was like most patterns of human movement; messy, unpredictable, with new groups mixing with old and the blended groups backcrossing and mixing with the ones who were left behind.  But this is what makes population genetics fascinating, isn't it?  It gives us a lens through which to view our own origins, and causes us to question the definition of terms like "race" that a lot of us think we understand -- but which, on analysis, turn out not to mean anything even vaguely scientific.

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Aptly enough, considering Monday's post about deciphering scripts, this week's Skeptophilia book recommendation is Steven Pinker's brilliant The Stuff of Thought.  Here, experimental psychologist Pinker looks at what our use of language tells us about our behavior and neural wiring -- what, in fact, our choice of words has to do with human nature as a whole.

Along the way, he throws out some fascinating examples -- my favorite of which is his section on the syntax of swearing.  I have to admit, the question, "Just what does the 'fuck' in 'fuck you' actually mean?" is something I've never thought about before, although it probably should have given that I'm guilty of using the f-word a lot more than is generally considered acceptable.

So if you're interested in language, the human mind, or both, this is a must-read.  Although I'll warn you -- if you're like me, it'll leave you thinking, "Why did I just say that?" several times a day.

Science shorts

After the last three days' depressing posts, I thought it was once again time to retreat to my happy place, which is: cool new scientific research.  So, for your reading entertainment, here are some early-summer shorts.

[Image licensed under the Creative Commons marcore! from Hong Kong, China, Board shorts 4, CC BY 2.0]

No, not those kind of shorts.  The scientific variety.

First, we have some research that appeared last week in the Journal of Applied Research in Memory and Cognition, done by Julia Soares and Benjamin Storm of the University of California.  In their paper, entitled, "Forget in a Flash: A Further Investigation of the Photo-Taking Impairment Effect," what Soares and Storm found that for reasons still unknown, taking a photo of something impairs your ability to remember it -- even if you know that you won't have access to the photo later.

The authors write:

A photo-taking-impairment effect has been observed such that participants are less likely to remember objects they photograph than objects they only observe.  According to the offloading hypothesis, taking photos allows people to offload organic memory onto the camera's prosthetic memory, which they can rely upon to “remember” for them.  We tested this hypothesis by manipulating whether participants perceived photo-taking as capable of serving as a form of offloading.  In [our] experiments, participants exhibited a significant photo-taking-impairment effect even though they did not expect to have access to the photos.  In fact, the effect was just as large as when participants believed they would have access to the photos.  These results suggest that offloading may not be the sole, or even primary, mechanism for the photo-taking-impairment effect.

The authors were interviewed by Alex Fradera for the Research Digest of the British Psychological Society, and there's a possible explanation for the phenomenon, although it's still speculative.  Fradera writes:

Soares and Storm have a speculative second interpretation.  They suggest that the effort involved in taking a photo – getting the framing right, ensuring the lens is in focus – leads to the sense that you’ve done a good job of encoding the object itself, even though you have been focusing more on peripheral features.  So you’re not mentally slacking-off because you think the camera has it covered – but because you think you already have.  It may be relevant that people who take photographs at events report afterwards feeling more immersed in the experience, which would tally more with this explanation than the disengagement-due-to-fiddling idea.  In any case this is further evidence that those of us who approach exciting life events through the lenses of our electronic devices may be distancing ourselves from fuller participation.

From the Department of Geophysics at the University of Texas comes a study of the most famous (although not, by a long shot, the largest) mass extinction event -- the Cretaceous-Tertiary Extinction of 65 million years ago, which took out the dinosaurs, with the exception of the ancestors of today's birds.  The accepted explanation of the event is a collision by a massive meteorite near what is now the Yucatán Peninsula, forming the Chicxulub Crater.

A long-unanswered question about mass extinctions such as this one is how fast life rebounded.  The problem is that the difference between a thousand, ten thousand, and a hundred thousand years in the geological record isn't that great, so the error rate for any estimates were bound to be high.  But now, geophysicists Chris Lowery, Gail Christeson, Sean Gulick, and Cornelia Rasmussen, working with Timothy Bralower, a micropaleontologist at Pennsylvania State University, have found evidence that narrows that window down -- and surprisingly, shows that life recovered pretty quickly.

The key was finding a sediment core that contained 76 centimeters of brown limestone that came from the years immediately following the impact.  It contained debris from the event, including crystals of "shocked quartz" (quartz crystals showing signs of sudden, extreme temperatures and pressures).  And what the researchers found was that a little as a few thousand years, the ecosystem was beginning to rebound.

"You can see layering in this core, while in others, they’re generally mixed, meaning that the record of fossils and materials is all churned up, and you can’t resolve tiny time intervals," Bralower said.  "We have a fossil record here where we’re able to resolve daily, weekly, monthly, yearly changes."

Speaking of catastrophes, a fascinating piece of research from Stanford University anthropologists Tian Chen Zeng, Alan Aw, and Marcus Feldman gives us a possible explanation for a peculiar calamity that the human race experienced only seven thousand years ago.  By analyzing the genetic diversity among human Y-chromosomal DNA (inherited only father-to-son) and comparing it to the diversity in mitochondrial DNA (inherited only mother-to-child), they found something decidedly odd; the data suggested a serious genetic bottleneck -- but one that affected only males.

The difference was huge.  Zeng et al. showed that the disparity would only make sense if there was a point about seven thousand years ago when there was one male with surviving descendants for every seventeen females.

Feldman writes, in a press release to EurekAlert!:

After the onset of farming and herding around 12,000 years ago, societies grew increasingly organized around extended kinship groups, many of them patrilineal clans - a cultural fact with potentially significant biological consequences. The key is how clan members are related to each other.  While women may have married into a clan, men in such clans are all related through male ancestors and therefore tend to have the same Y chromosomes.  From the point of view of those chromosomes at least, it's almost as if everyone in a clan has the same father. 

That only applies within one clan, however, and there could still be considerable variation between clans.  To explain why even between-clan variation might have declined during the bottleneck, the researchers hypothesized that wars, if they repeatedly wiped out entire clans over time, would also wipe out a good many male lineages and their unique Y chromosomes in the process.

So as weird as it sounds, if you go back a few thousand years, we all have far fewer unique male ancestors than unique female ancestors.


Last, I would be remiss if I didn't make at least a brief mention of research that appeared in the Journal of Clinical Endocrinology and Metabolism last week.  Authored by Audrey J. Gaskins, Rajeshwari Sundaram, Germaine M. Buck Louis, and Jorge E. Chavarro, the paper was entitled "Seafood Intake, Sexual Activity, and Time to Pregnancy," and amongst its conclusion was that the quantity of seafood eaten correlates positively with the number of times per month people have sex.

The researchers speculate that the reason may be the higher quantity of long-chain omega-3 fatty acids, common in seafood, has an effect on the reproductive hormones, increasing sex drive.  It does, however, make me wonder how anyone thought of correlating these, but my puzzlement is probably indicative of why I never went into research.

In any case, I thought it was interesting.  And makes me glad I brought leftover scampi for lunch.  Hope springs eternal, you know?

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This week's recommended book is one that blew me away when I first read it, upon the urging of a student.  By groundbreaking neuroscientist David Eagleman, Incognito is a brilliant and often astonishing analysis of how our brains work.  In clear, lucid prose, Eagleman probes the innermost workings of our nervous systems -- and you'll learn not only how sophisticated it is, but how easy it can be to fool.

Cherry-picking DNA

It is a frequent source of perplexity for me when people read about scientific research, and because of their own biases (1) claim that it says something it clearly doesn't say, or else (2) deny it completely.  After all, as eminent astrophysicist Neil DeGrasse Tyson put it, "The good thing about science is that it's true whether or not you believe in it."

I ran into a particularly good (or appalling, depending on how you look at it) example of this yesterday over at Science Online, the news outlet for the American Association for the Advancement of Science, in article by Michael Price, entitled, "‘It’s a Toxic Place:’ How the Online World of White Nationalists Distorts Population Genetics."  Price interviewed Jedidiah Carlson, a graduate student in bioinformatics at the University of Michigan - Ann Arbor, about how the recent explosion in personal DNA analysis had been hijacked by white supremacists.

Carlson discovered the problem when he was looking online for a 2008 paper in Nature that analyzed hundreds of thousands of point mutations in people of various ethnic groups, and found that the paper had been linked in the notorious neo-Nazi site Stormfront.  Shocked but curious, he clicked the link, and found himself in a darker realm of genetic research -- using DNA evidence to support the bogus ideas that (1) races are little water-tight compartments except for cases of deliberate "race mixing," and (2) that people of western and northern European descent are superior to everyone else on the planet.

Norman Rockwell, The Golden Rule (1961)

Carlson started searching through Stormfront and other white supremacist sites, and found that this is an increasingly common phenomenon.  "People will grab figures from scientific papers and edit them in several different ways to make them look like they support the white nationalist ideology," Carlson said.  "For instance, in [the] 2008 Science paper, researchers published a figure with a plot inferring regional ancestry of dozens of different populations around the world.  Based on the genetic compositions of hundreds of individuals, the figure divided the populations into clusters that revealed patterns in their ancestral population structure.  So [people on the forums] take this plot and add some subtle text like 'The genetic reality of race,' with no context showing what the scientists were actually looking at, and ignoring the fact that there’s a continuum among the individuals.  Then they turn these images into memes and try to make them go viral."

They don't just cherry-pick data; they cherry-pick entire studies -- as long as there's some conceivable way to twist them around to support their ideology.  "They’re interested in anything that would reinforce traditional, discrete racial categories. Intelligence is probably the number one topic that they gravitate toward," Carlson said.  "And anything pertaining to history of human migrations, or things that play into traditional classifications of racial phenotypes like facial morphology or skin color.  There was a paper on lactose tolerance in Europeans and that turned into this weird viral YouTube trend where white nationalists were chugging bottles of milk, presumably to flaunt their European heritage."

I don't know about you, but that strikes me as a weird thing to be proud of.  "Look how well I digest milk" is not something you often hear people say.  I mean, my Louisiana heritage is probably why I love Cajun cuisine, wherein the Four Major Food Groups are onions, garlic, hot peppers, and grease,  but I have no desire to video myself eating a bowl of gumbo, and doing the Fists In The Air Of Victory afterwards.

Carlson himself has become something of a target, after his observations about the use of genetic research by white supremacists was the subject of an interview in The Atlantic.  It was a shock to him, however, to find how virulently they responded to his central claim, which was that the supremacists were warping the conclusions of the research to support their bigoted worldview, and ignoring any evidence to the contrary.  "When they finally saw it, the first few comments were actually rather celebratory, as they saw the article as evidence that the 'liberal, biased, Jew-controlled media' are nervous about the growth of white nationalism.  About me, there were comments like, 'He says he’s a grad student, but he’s probably never even seen a principal component analysis plot,' which is ironic because that’s about half of my dissertation.  And it was pretty alarming seeing my name on the site.  After that, I took a break from doing this work for a while for my own mental health."

His alarm is understandable.  These people are unstable, prone to violence, and usually well-armed.  It's not stopping Carlson, however, although he does acknowledge that fighting this kind of bias is an uphill battle at best.  "I don’t think engaging them directly will work," he says.  "In an argument between a logical person and illogical person, the logical person is always going to lose because the illogical person isn’t playing by the same rules.  The misappropriations and misinterpretations run so deep that you’ll just get shouted down and personally attacked, and you’re not going to change anyone’s mind.  But I think there’s growing recognition that we as scientists bear some responsibility for guiding the public interpretation of our work."

Of course, that's not easy.  You put the data out there, analyze it as rigorously as you can, state your conclusion as clearly as you can, and hope for the best.  The science deniers of the world will always find a way to get around it, either by claiming the data is faulty, the analysis is in error, the scientist(s) who did the research were paid shills and are trying to fool everyone for their own nefarious purposes, or (if none of these work) simply by ignoring the study entirely.  We've seen it over and over with climate change deniers and young-Earth creationists, both fundamentally anti-scientific views of the universe.  The same is true here; the white supremacists have their conclusion already figured out -- that they're better than everyone else based on their ancestry and skin color -- and the research needs either to fit that model, or it's rejected as "liberal, biased, [and] Jew-controlled."

The funny postscript to all of this is that when I did 23 & Me a few months ago, purely out of curiosity, I was honestly disappointed that my DNA didn't have any particular surprises.  My ancestry is primarily French, Scottish, Dutch, German, and English, and my DNA said that my ancestry is... French, Scottish, Dutch, German, and English.  I'd have been delighted if there'd been a random West African or Southeast Asian in there somewhere, as unlikely as that seems given my appearance.  Race is primarily a social, not a genetic, construct, as research by groundbreaking population geneticist Luigi Luca Cavalli-Sforza showed decades ago.  We're all mixtures, and if you go back far enough, we're all related.

So if you like to see races as neat little compartments with hard-and-fast boundaries, that's up to you.  But the bottom line is that you're wrong.  The view supported by science -- that the boundaries between ethnic groups are fluid, and almost all of us have diverse ancestry -- is true, as Tyson said, whether or not you believe it.

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This week's book recommendation is a brilliant overview of cognitive biases and logical fallacies, Rolf Dobelli's The Art of Thinking Clearly.  If you're interested in critical thinking, it's a must-read; and even folks well-versed in the ins and outs of skepticism will learn something from Dobelli's crystal-clear prose.

When the volcano blows

Nobel Prize-winning physicist Richard Feynman once said, "I would rather have questions that cannot be answered than answers that cannot be questioned."

The strength of science is in its ability to self-correct, but this does engender a problem; it may well be that some of the questions we're asking will never be satisfactorily answered.  There are sometimes when we must admit ignorance, and hold our determination to have everything figured out in abeyance -- possibly indefinitely.

That may be the situation we're in with regards to an interesting question surrounding the largest volcanic eruption in modern times, the eruption of Toba in the Indonesian archipelago.  This eruption dwarfed Mount Saint Helens, the 1883 eruption of Krakatoa, and even the catastrophic eruption of Tambora (also in Indonesia) in 1815, that threw so much in the way of debris up into the atmosphere that it caused the "Year Without a Summer," in which Quebec City got a foot of snow -- in mid-July.

The Toba eruption, 74,000 years ago, was bigger than all of the above; by some estimates, it threw a hundred times more in the way of pulverized rock into the air than Tambora did.  It is certain that it caused not only localized devastation, but worldwide climate change.  And the conventional wisdom is that it nearly wiped out the human species -- that we were driven into a genetic bottleneck, in which only a few survivors became the ancestors of everyone currently alive today.

The Toba caldera [image courtesy of the Wikimedia Commons]

Michael Rampino and Stanley Ambrose, of New York University, were amongst the first proponents of the Toba bottleneck theory.  In their paper "Volcanic Winter in the Garden of Eden: The Toba Supereruption and the Late Pleistocene Human Population Crash," published in 2000 in the Papers of the Geological Society of America, they write:

Genetic studies indicate that sometime prior to ca. 60,000 yr ago humans suffered a severe population bottleneck (possibly only 3,000-10,000 individuals), followed eventually by rapid population increase, technological innovations, and migrations.  The climatic effects of the paroxysmal Toba eruption could have caused the bottleneck, and the event might have been a catalyst for the technological innovations and migrations that followed.  The present results as to the predicted environmental and ecological effects of the eruption lend support to a possible connection between the Toba event and the human population bottleneck, and suggest that similar bottlenecks among other organisms might be expected at about the same time. 

However, it appears that the question is far from settled.  A paper by Eugene Smith et al. that came out last week in Nature, "Humans Thrived in South Africa Through the Toba Eruption about 74,000 Years Ago," completely counters the conventional wisdom -- and suggests that if the bottleneck did occur, it may not have been the fault of the volcano:

Approximately 74 thousand years ago (ka), the Toba caldera erupted in Sumatra.  Since the magnitude of this eruption was first established, its effects on climate, environment and humans have been debated.  Here we describe the discovery of microscopic glass shards characteristic of the Youngest Toba Tuff—ashfall from the Toba eruption—in two archaeological sites on the south coast of South Africa, a region in which there is evidence for early human behavioural complexity.  An independently derived dating model supports a date of approximately 74 ka for the sediments containing the Youngest Toba Tuff glass shards.  By defining the input of shards at both sites, which are located nine kilometres apart, we are able to establish a close temporal correlation between them.  Our high-resolution excavation and sampling technique enable exact comparisons between the input of Youngest Toba Tuff glass shards and the evidence for human occupation.  Humans in this region thrived through the Toba event and the ensuing full glacial conditions, perhaps as a combined result of the uniquely rich resource base of the region and fully evolved modern human adaptation.

The reason I bring this up -- besides the fact that I'm interested in human population genetics, and it's cool -- is that this may be a question that we simply don't have the data to answer.  It's possible that the "thriving" population that Smith et al. found was a localized group of lucky people, and elsewhere, humanity got clobbered.  On the other hand, it could be that the Rampino and Ambrose paper was simply wrong -- that the population genetics studies, which are not without their a priori assumptions, overestimated the extent of the Toba bottleneck (or the whatever-caused-it bottleneck).

But -- and this is the most critical point -- you keep looking.  If there's no definitive solution, you are forced to admit it, but the research doesn't stop there.  Ignorance is the beginning, not the end, of the scientific process.

So we may never know exactly how close humanity came to extinction 74,000 years ago.  The important thing is that we've asked the question -- and that science gives us a means to evaluate the evidence, and determine if a particular answer is supported.  And what we learn along the way will open up further avenues for exploration, enough to keep the scientific world occupied for a long, long time.

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Religious mutants

A couple of days ago, a reader of Skeptophilia sent me a link along with an email, the gist of which was, "Ha ha, how are you gonna argue your way out of this one, Mr. Smarty-Pants Atheist?"

The link was to a recent article in Newsweek entitled, "Religious People Live Healthier, Longer Lives -- While Atheists Collect Mutant Genes."  Notwithstanding the mental image this created -- of us atheists having stamp-collection-like binders of mutant genes on bookshelves in our studies -- the whole premise sounded idiotic.  The article quotes study co-author Edward Dutton as saying:

Maybe the positive relationship between religiousness and health is not causal—it's not that being religious makes you less stressed so less ill.  Rather, religious people are a genetically normal remnant population from preindustrial times, and the rest of us are mutants who'd have died as children back then...  [The Industrial Revolution caused us to develop] better and better medical care, easier access to healthy food and better living conditions.  Child mortality collapsed down to a tiny level and more and more people with more and more mutant genes have survived into adulthood and had children...  Religiousness makes you more pro-social, and you become more religious when you're stressed.  Religious people would have been sexually selected for because their pro-social, moral, unstressed nature would be attractive.

Well, my background is in evolutionary genetics, so I thought, "Here's a claim I'm qualified to evaluate."

Let's look first at his contention that religious people are healthier.  Turns out that there's some weak correlation there, but only if you look at First-World countries.  In the United States, for example, comparing religious people and non-religious people of similar socioeconomic status, there's a small improvement in health and longevity in the religious people over the non-religious ones.  (It very much remains to be seen that there's any kind of causal relationship there, however.)  But if you look at the human race as a whole -- comparing largely non-religious countries (Sweden, Finland, Iceland) with largely religious ones (Bangladesh, Malaysia, Egypt) gives you exactly the opposite pattern.  There's as much evidence that ill people in questionable living conditions seek out religion as solace as there is that religion itself makes you healthier.

[image courtesy of the Wikimedia Commons]

The last part of the claim, that religion is due to some kind of sexual selection, moves us into even muddier waters.  If this claim is true, people would be eliminating potential mates on the basis of being non-religious, something I see no evidence of whatsoever.  Also, there's the problem of people like me -- the child of a dad who was a Pascal's-wager kind of guy and a mom who was more or less the Cajun Mother Teresa.  So I almost certainly inherited "religiosity genes" (whatever those are).  My first wife, and the mother of my children, was an agnostic who didn't really care about the question of god one way or the other, and at the time our two sons were born, I was still trying like hell to find a reason to believe, a battle I gave up when my youngest son was about five.

So how do you classify me, on the Religious Mutant Gene scale?

Anyhow, as befits a good skeptic, I decided to go to the source, and went to the paper by Dutton et al. in the journal Evolutionary Psychological Science that makes the original claim.  The paper has the rather histrionic title, "The Mutant Says in His Heart, 'There Is No God': the Rejection of Collective Religiosity Centred Around the Worship of Moral Gods Is Associated with High Mutational Load," and although the entire paper is behind a paywall, the abstract reads as follows:

Industrialisation leads to relaxed selection and thus the accumulation of fitness-damaging genetic mutations.  We argue that religion is a selected trait that would be highly sensitive to mutational load.  We further argue that a specific form of religiousness was selected for in complex societies up until industrialisation based around the collective worship of moral gods.  With the relaxation of selection, we predict the degeneration of this form of religion and diverse deviations from it.  These deviations, however, would correlate with the same indicators because they would all be underpinned by mutational load.  We test this hypothesis using two very different deviations: atheism and paranormal belief.  We examine associations between these deviations and four indicators of mutational load: (1) poor general health, (2) autism, (3) fluctuating asymmetry, and (4) left-handedness.  A systematic literature review combined with primary research on handedness demonstrates that atheism and/or paranormal belief is associated with all of these indicators of high mutational load.

Mutational load is a real thing -- it's the number of lethal (or at least significantly deleterious) genes we carry around, the effects of which we are usually protected from by our diploidy (we've got two copies of every gene, and if one doesn't work, chances are the other one does).  But there is no indication that high mutational load is connected with autism (jury's still out on what exactly causes autism) or left-handedness, and "poor general health" is such a mushy term that if you select your data set carefully enough you could probably correlate it with anything you like, up to and including astrological sign.  (There is some indication that left-handedness correlates with some medical conditions, such as migraine, autoimmune disorders, and learning disability; but the heritability of left-handedness even when both parents are left-handed is only 29% anyhow, and what exactly causes it is still unknown.)

But then I did what (again) all skeptics should do, namely take a look at the paper's sources.  I noticed two things right away -- first, that the sources from highly-respected journals like Nature were only tangentially connected to Dutton et al.'s claim (such as an article on the heritability of longevity in Nature Genetics), and second, that the authors are really good at citing their own work.   No fewer than ten of the sources were authored or co-authored by Dutton or the other two authors of the Evolutionary Psychological Science paper, Curtis Dunkel and Guy Madison.

Then I scrolled a little further, and found these listed as sources:

• Copping, J. (2013). Who you gonna call? Belief in ghosts is rising. Telegraph, http://www.telegraph.co.uk/news/newstopics/howaboutthat/10310018/Who-you-gonna-call-Belief-in-ghosts-is-rising.html
• Daily Mail Reporter. (2011). The ghost map: Yorkshire tops spook league with a third of adults claiming to have seen a spectre. MailOnline, http://www.dailymail.co.uk/news/article-1362452/The-ghost-map-Yorkshire-tops-spook-league-adults-claiming-seen-spectre.html
• Greenfield, P. (2017). Christians should pray for Prince George to be gay, says minister. Guardian, https://www.theguardian.com/uk-news/2017/dec/01/christians-should-pray-from-prince-george-to-be-gay-says-c-of-e-minister
• Kelley, M. (2011). Correlates of paranormal beliefs I: schizotypy. Journal of Paranormal Psychology, 75, 301–325.
• Malloy, N. (8 February 2017). Christian girls are beautiful and here’s why. Jesus Tribune. http://jesustribune.com/christian-girls-are-beautiful
• Yahoo Answers. (2008). Why are Mormon girls so hot? https://answers.yahoo.com/question/index?qid=20080713143021AAdArue
• Yelp. (2010). OMG … Why are Christian women extremely [physically] attractive? https://www.yelp.com/topic/los-angeles-omg-why-are-christian-women-extremely-physically-attractive

So you're writing a serious paper in a (presumably) serious journal, and you want us to accept your claim, and you cite Yelp, Yahoo Answers, The Telegraph, The Guardian, The Daily Mail Fail, and -- for fuck's sake -- The Jesus Tribune?

What this makes me wonder -- besides the obvious question of how Dutton et al. pull this stuff out of their asses without cracking up -- is about the reliability of the journal Evolutionary Psychological Science itself.  I wasn't able to find any meta-analysis of EPS's reliability online; that sort of self-policing by academia is sorely lacking.  But this paper has all the hallmarks of a pay-to-play publication in a journal that honestly doesn't give a flying fuck about the study's quality.  It's hard to imagine any study that cites The Jesus Tribune making it into Science, for example.

So predictably, I'm unimpressed.  Nothing in my understanding of population genetics lends the slimmest credence to this claim.  It's unsurprising that Newsweek picked up the story, although one would hope that even popular media publications would be a little more careful what they print.  In any case, we atheists don't have to worry about our being poorly-fit unhealthy left-handed autistic mutants.  We're no more likely to be any of the above than the rest of the general population is.  Although, I have to say that while we're talking fiction, if mutations could work like they do in The X-Men, I'd be all for 'em.  I want a mutation that gives me wings.  Big, feathery hawk wings arising from my shoulders.  It'd make fitting into a shirt difficult, but that's a price I'm willing to pay.

All in the family

Racists have cast about for years for some sort of scientific basis for their horrible worldview.  Evidence that their race is the superior one in intelligence, physical strength, or vigor, or simply support for their contention that interracial marriages are bad in a biological sense.

Of course, the problem for people who turn to science is that science often provides answers whether you end up liking them or not.  And inquiries into a biological basis for race have shown that any real genetic variations between different ethnic groups are tenuous at best.  Luigi Luca Cavalli-Sforza, one of the leading specialists in human population genetics, says:

Human races are still extremely unstable entities in the bands of modern taxonomists…  As one goes down the scale of the taxonomic hierarchy toward the lower and lower partitions, the boundaries between clusters become even less clear.  There is great genetic variation in all populations, even in small ones. 

From a scientific point of view, the concept of race has failed to obtain any consensus… the major stereotypes, all based on skin color, hair color and form, and facial traits, reflect superficial differences that are not confirmed by deeper analysis with more reliable genetic traits and whose origin dates from recent evolution mostly under the effect of climate and perhaps sexual selection.

Now, let me make it clear that this doesn't mean that there are no differences between racial groups.  It's just that those differences are primarily social and cultural, not biological, which neatly kicks the legs out from underneath some of the racists' primary arguments.

[image courtesy of the Wikimedia Commons]

And it's been known for years that lumping together all dark-skinned Africans as "black" is ignoring the fact that there's more genetic variability on the African continent than there is in the entire rest of the world put together.  The Zulu and the !Kung people of southern Africa, for example, are more distantly related to each other than a typical white American is...

... to a person from Japan.

And just last month, Iain Mathieson of Harvard University punched another hole in racist genetics when he released his research team's findings that the genes for white skin are only about 8,000 years old.

According to Mathieson et al.:

(M)odern humans who came out of Africa to originally settle Europe about 40,000 years are presumed to have had dark skin, which is advantageous in sunny latitudes.  And the new data confirm that about 8500 years ago, early hunter-gatherers in Spain, Luxembourg, and Hungary also had darker skin:  They lacked versions of two genes—SLC24A5 and SLC45A2—that lead to depigmentation and, therefore, pale skin in Europeans today... 

Then, the first farmers from the Near East arrived in Europe; they carried both genes for light skin. As they interbred with the indigenous hunter-gatherers, one of their light-skin genes swept through Europe, so that central and southern Europeans also began to have lighter skin.  The other gene variant, SLC45A2, was at low levels until about 5800 years ago when it swept up to high frequency.

The reason the two light-skin genes took hold in northern latitudes is thought to be vitamin D synthesis -- while having dark skin is an advantage in equatorial regions, from the standpoint of protection from ultraviolet skin damage, dark skin inhibits endogenous vitamin D production in areas with low incident sunlight.  So once the mutations occurred, they spread rapidly, but only in regions at high latitude.  This explains why even distantly-related equatorial groups have dark skin (such as the Bantu and the Australian Aborigines), and even distantly-related high-latitude group have light skin (such as the Swedes and the Inuit).

And apparently the gene for blue eyes is of equally recent vintage.  The earliest genetic evidence for the gene HERC2/OCA2, which causes blue eyes, is in southern Sweden from about 7,700 years ago.  The gene's provenance might date back to 10,000 years ago, but certainly not much before that.

So all of us descend from dark-skinned, brown-eyed people.  Sorry, white supremacists.

Of course, given that there is good evidence that around 70,000 years ago, an eruption of the Toba Volcano in Indonesia caused climate shifts that killed nearly all of our ancestors -- best estimates are that there were only 10,000 humans left on Earth after the bottleneck occurred -- we're all cousins anyway.  After that event, those 10,000-odd survivors can be put into two groups; the ones who left no descendants at all, and the ones who are the ancestors of everyone on Earth.

It'd be nice if we could count on people using science to inform their behavior, but we don't have a very good track record in that regard, do we?  I mean, think about it; we're still pushing the fossil fuel industry as the world warms up and the climate destabilizes around us.  So unfortunately, even when we have direct and incontrovertible evidence that what we're doing isn't reasonable, we usually continue doing it.

And I guess the argument that the genes for white skin are 8,000 years old is going to gain no traction whatsoever with the people who believe that the Earth is 6,000 years old.

But still, it'd be nice, wouldn't it?  Just as the first photographs of the Earth taken from the Moon changed a lot of folks' perspective on our place in the universe, it'd be wonderful if research like this could alter us from "those people... they're not like us" to "we're all one family, and we're all in this together."

Skin deep

We were talking in my AP Biology class yesterday about the potential for skin damage from exposure to ultraviolet light.  Later in the day,  a student sent me a YouTube video called "How the Sun Sees You" that uses a UV-sensitive camera to see the sun damage on people's skin (and also illustrates that sunscreen does work, given that it looks an opaque black when filmed in the ultraviolet region of the spectrum).

All of which is well and good, but then I scrolled down to the comments section, which I know I should never do, and I found the following.  Spelling and grammar are as written, so I don't use up my "sic" allotment all in one go:

First off everyone has to stop believing that Melanin a.k.a. Carbon protects us from u.v. rays.  Carbon in the skin actually absorbs ultraviolet rays in a process that is now being called Ultrafast Internal Conversion.  Not one person has mentioned this..  The Elemental Compound for C Carbon is 666.  6 Electrons 6 Neutrons 6 Protons.  The origins of the 666.  The Catholics call It "the mark of beast" which is code for "mark of the our destroyers"  We all know that Carbon is the building blocks of life.  Carbon defines life therefore us Moors who are incorrectly referred to as "Black People" are the building blocks for Human life and biology.  This is true because no one else on the planet possesses the levels of Carbon in the body and brain quite like The Moors. (remember a moor is a black man or women)  In other words, us "Black people" are and forever will be The genetic template for the Human being.  Black ppl we are Human In it's truest form.  Of course there are plenty lies circulating the damn truth.  All non black people are merely human hybrids.  All races were genetically engineered from the supreme Human.  Clones much?  DARK POWER!!

So naturally I thought, "Well, that's a viewpoint I've never run into before."  (I also thought, "I hope this person is on medication" and "this is what it looks like when someone fails high school biology.")  But I did some research, and I found out that this is not the claim of a lone wacko.  This is the claim of a large number of wackos.  There's a whole school of thought (although I hesitate to use either word in this context) that revolves around the contention that people of African descent are superior because they have lots more carbon in them.

Take, for example, the page "Carbon & Melanin Secret of Secrets" over at the amazingly wacky site Godlike Productions.  In it, we find a wall of text that can be summarized as follows:

• Carbon is some seriously mystical stuff.  Besides the 6-6-6 thing mentioned above, it has four bonds that are shaped like a swastika.
• It also has something to do with the Buddhist "om," the Christian cross, and the Greek letters alpha and omega.
• Melanin is dark.  So is carbon.  Therefore melanin is carbon.
• Melanin is the "key to life" and is the "organizing molecule for living systems."
• Melanin is an ordinary conductor, a semiconductor, and a superconductor.  Don't ask me how it can be all three at the same time.
• Satan and Saturn are the same thing.
• Because the symbol for carbon is C, and the symbol for cytosine (one of the nitrogenous bases in DNA) is C, they're the same thing.  It couldn't be because in English, both of them have names that start with "c."
• Some other weird stuff about DMT and alchemy and prophecies that frankly I couldn't read because my eyes were spinning.

I read this whole thing with an expression like this:

What bothers me most about all of this is not that crazy people are making shit up.  That's what crazy people do, after all.  What bothers me is that apparently this claim has gotten some traction amongst people who want justification for believing that dark-skinned humans are intrinsically better than light-skinned humans, and who cannot even be bothered to take a look at the Wikipedia page for melanin, wherein we find that melanin isn't carbon.  It contains carbon, but after all, so does chalk, which last I looked was white.

The ironic thing is that when you talk to actual anthropologists and geneticists, most of 'em will tell you that the biological basis for race is tenuous at best.  Race is a cultural phenomenon, not a genetic one.  If you want your mind blown on this topic, consider the following quote from Alan Goodman:

Richard Lewontin did an amazing piece of work which he published in 1972, in a famous article called "The Apportionment of Human Variation." Literally what he tried to do was see how much genetic variation showed up at three different levels. 

One level was the variation that showed up among or between purported races. And the conventional idea is that quite a bit of variation would show up at that level. And then he also explored two other levels at the same time. How much variation occurred within a race, but between or among sub-groups within that purported race. 

So, for instance, in Europe, how much variation would there be between the Germans, the Finns and the Spanish? Or how much variation could we call local variation, occurring within an ethnicity such as the Navaho or Hopi or the Chatua? 

And the amazing result was that, on average, about 85% of the variation occurred within any given group. The vast majority of that variation was found at a local level. In fact, groups like the Finns are not homogeneous - they actually contain, I guess one could literally say, 85% of the genetic diversity of the world. 

Secondly, of that remaining 15%, about half of that, seven and a half percent or so, was found to be still within the continent, but just between local populations; between the Germans and the Finns and the Spanish. So, now we're over 90%, something like 93% of variation actually occurs within any given continental group. And only about 6-7% of that variation occurs between "races," leaving one to say that race actually explains very little of human variation...

But, for the most part, you know that the basic human plan is really the basic human plan, and is found almost anywhere in the world. Most variation is found locally within any group. Why don't we believe that? Because we happen to ascribe great significance to skin color, and a few other physical cues... And, in fact, though, these may happen to be a few of the things that do widely vary from place to place. But, that's not true under the skin. Rather, quite another story is told by looking at genes under the skin.

Which should really inform us about how we treat people who don't look like us, shouldn't it?  We're all human.  We have a vast overlap in our genetics, even if you choose two people who look very different from each other.  And at our cores, most of us want the same things -- food, shelter, love, security, compassion.  When we start claiming that people of different ethnicities deserve different levels of privilege, we're engaging in a mindset that is not only destructive, it's counterfactual.

And that applies to all racists equally, whether they're neo-nazis or cranks who claim that anyone without much melanin in their skin is an evil hybrid clone.

Race, ethnicity, Einstein, and King Tut

Today we have two stories that are mostly interesting in juxtaposition.

First, we have an article by Jo Marchant over at Medium entitled, "Tutankhamun's Blood," wherein we hear about the work done by Yehia Gad to sequence the young pharaoh's DNA -- and how it set off a war over what race/ethnic group gets to claim him.  First, there was concern that the test would show a connection between the Egyptian king and... *cue dramatic music* the Jews:

The editor of Archaeology magazine, Mark Rose, reported in 2002 that [proposed DNA testing] was cancelled “due to concern that the results might strengthen an association between the family of Tutankhamun and the Biblical Moses.” An Egyptologist with close links to the antiquities service, speaking to me on condition of anonymity, agreed: “There was a fear it would be said that the pharaohs were Jewish.”

Specifically, if the results showed that Tutankhamun shared DNA with Jewish groups, there was concern that this could be used by Israel to argue that Egypt was part of the Promised Land.

This might seem an outlandish notion, but given the context of the Middle Eastern history, it is understandable...  For many Egyptians, the idea that their most famous kings could share some common heritage with their enemies is a hard one to cope with.

Yet the possibility that Tutankhamun could share some DNA with ancient Jewish tribes is not far-fetched, says Salima Ikram, an Egyptologist and mummy specialist at the American University in Cairo. After all, the royal family might well have shared genes with others who originated in the same part of the world. “It is quite possible that you might find Semitic strains of DNA in the pharaohs,” she says. “Christians, Jews, Muslims—they all came from a similar gene pool originally.”

Yehia Gad finally was allowed to do the DNA testing, under the direction of an Egyptian antiquities expert, the archaeologist Zahi Hawass, and the results turned out to be controversial, but for a different reason:

A Swiss genealogy company named IGENEA issued a press release based on a blurry screen-grab from the Discovery documentary. It claimed that the colored peaks on the computer screen proved that Tutankhamun belonged to an ancestral line, or haplogroup, called R1b1a2, that is rare in modern Egypt but common in western Europeans...  This immediately led to assertions by neo-Nazi groups that King Tutankhamun had been “white,” including YouTube videos with titles such as King Tutankhamun’s Aryan DNA Results, while others angrily condemned the entire claim as a racist hoax. It played, once again, into the long-running battle over the king’s racial origins. While some worried about a Jewish connection, the argument over whether the king was black or white has inflamed fanatics worldwide. Far-right groups have used blood group data to claim that the ancient Egyptians were in fact Nordic, while others have been desperate to define the pharaohs as black African. A 1970s show of Tutankhamun’s treasures triggered demonstrations arguing that his African heritage was being denied, while the blockbusting 2005 tour was hit by protests in Los Angeles, when demonstrators argued that the reconstruction of the king’s face built from CT scan data was not sufficiently “black.”

If that's not ridiculous enough, just yesterday we had a story from Haaretz about an apparently insane Iranian cleric who claims that Albert Einstein was actually a Shi'a Muslim:

The report cites a video by Ayatolla Mahadavi Kani, described as the head of the Assembly of Experts in the Islamic Republic of Iran, who says that there are documents proving the Jewish scientist embraced Shiite Islam and was an avid follower of Ja'far Al-Sadiq, an eighth-century Shi'i imam.

In the video, Kani quotes Einstein as saying that when he heard about the ascension of the prophet Mohammed, "a process which was faster than the speed of light," he realized "this is the very same relativity movement that Einstein had understood."

The ayatollah adds: "Einstein said, 'when I heard about the narratives of the prophet Mohamad and that of the Ahle-Beit [prophet's household] I realized they had understood these things way before us.'"

What I find wryly amusing about all of this he's-mine-no-he's-mine tug-of-war over famous historical figures is how it ignores the reality of what race and ethnic identification actually are.  There is some biological basis for race, which is how we can generate cladograms for ethnic groups like the one pictured below:

Note what is, for some people, the most surprising thing about this tree; two very dark-skinned individuals, one a Native Australian and the other a Bantu from Zimbabwe, are far more distantly related to each other than an Englishman is related to a guy from Japan -- even though both the Bantu and the Australian are routinely lumped together as "Black," and the Englishman and the Japanese consider themselves different races.

Professor Emeritus Luigi Luca Cavalli-Sforza, the acclaimed and much-cited population geneticist at Stanford, writes, "Human races are still extremely unstable entities in the bands of modern taxonomists…  As one goes down the scale of the taxonomic hierarchy toward the lower and lower partitions, the boundaries between clusters become even less clear…  There is great genetic variation in all populations, even in small ones.  From a scientific point of view, the concept of race has failed to obtain any consensus…the major stereotypes, all based on skin color, hair color and form, and facial traits, reflect superficial differences that are not confirmed by deeper analysis with more reliable genetic traits and whose origin dates from recent evolution mostly under the effect of climate and perhaps sexual selection."

That's not to say that there's nothing to race at all.  Self-perception, privilege, culture, religion, and language are all strongly connected to, and influenced by, race and ethnicity.  But the genetic connection is tenuous at best, which is why I always find it funny when someone tells me that (s)he is "1/32 Native American," and then decides to adopt a Native name, wear Native-style jewelry and clothing, and so on.  By the time your ancestry has that small a proportion from any ethnic group, you are hardly Native American in any cultural sense, so doing all that sort of stuff -- and yes, I know more than one person who does -- is little more than an affectation.

But it's also not to say that I'm not proud of my roots.  My family is predominantly French and Scottish, with some Dutch, German, English, Irish, and Native American thrown in for good measure (and the latter, I'm afraid, isn't much more than 1/32 of my heritage).  Ethnically, I'm a southern Louisianian, and if you don't think that's an ethnic and cultural group, you should spend some time in Lafayette, Louisiana.  But I am, at the same time, fully aware of how fluid a concept ethnic identification is.  I've lost most of my Cajun accent in the three decades I've lived in YankeeLand, and my children -- who share about the same proportion of Cajun blood I do, since their mother was also half south-Louisiana-French by ancestry -- were raised in upstate New York and therefore aren't ethnically Cajun at all.

And all of this is why the wrangling over whether King Tut was "actually" European (or Black, or Semitic, or whatever) and whether Albert Einstein was "actually" a Muslim, is ridiculous.  We are all mixtures of genetics and culture; and each of those brings along with it physical and cultural baggage.  It's wonderful when someone embraces his or her ethnicity for the positive features (the perspective on the world, the music, the language, the food) and jettisons the negative aspects (the divisive us-vs.-them mentality, the notions of superiority and inferiority, the assumption of privilege).  An understanding of what ethnicity and race are, and are not, is a critical step in growing into a world where we value each other's shared humanity more than we worry about what labels we choose to place on ourselves.