German Joys

What Made the Black Death so Deadly

Maggie Koerth-Baker reports the pretty amazing fact that if you happened to get infected with Yersinia pestis -- the bacterium that caused the Black Plague -- today, you would have a 97% chance of surviving even without modern medical care. So why did it kill between 30-50% of Europeans in the 14th century? To find out, scientsts have been looking for ancient plague DNA:

 

In 2011, a team led by McMaster University paleogeneticist Hendrik Poinar became the first to reconstruct a full genome for Black Death era Yersinia pestis.

This was not a full and complete genome drawn from a single bacterium inhabiting the body of a single victim. Instead, the genome was patched together from bits and pieces of DNA in remains taken from London's East Smithfield cemetery. The small chunks were lined up to create a whole, similar to the way you make a panoramic photo by combining a series of different shots. Hendrik Poinar calls it a "draft" of the genome, rather than a smooth, polished work of biology.

The draft tells us a couple of things. First, the Y. pestis of the Black Death era is related to modern Y. pestis. In fact, it's probably the ancestor of all the strains of Y. pestis that exist today. Second — and this is the weird part — there is really not much difference between the old Y. pestis and the new. It boils down to about 100 genetic changes, few of which seem to have given the bacteria enough of an evolutionary advantage that they spread widely through the population.

Genetically, Y. pestis has barely changed. Its infection profile in the real world, though, has changed massively. That suggests that at least some of those small alterations in the genome must have been extremely important. But which ones? And why? To answer those questions, you could reverse-engineer the evolution of Y. pestis in the lab. "We'd have an opportunity to test those changes, one at a time, and find out," Poinar said. "... If we could do it in a form or fashion that wouldn't terrify people."

So, who's going to join me in volunteering to be infected with ancient plague for Science? After all, with modern medical care, there's probably at least an 80% chance of survival. I like those odds!

Condorcet v. The Circle-Squaring Cranks

While cloistering myself in the Natural Sciences Library to finish an article, I happened upon a book called Squaring the Circle, which is a minute historical exploration of that famous scientific problem, written in 1911 in impeccably dry English scientific prose by one E.W. Hobson, Sc.D, LL.D., F.R.S., Sadleirian Professor or Pure Mathematics, and Fellow of Christ's College, in the University of Cambridge. This biography of Hobson observes that he was '[b]rought up in rigidly Low Church surroundings ...' but 'developed strong views of rationalism, becoming ... an avowed radical and agnostic'. On pages 3 and 4, he notes that attempts to solve this famously insoluble problem* have occupied uncounted cranks over the centuries:

The solutions propounded by the circle squarer exhibit every grade of skill, varying from the most futile attempts, in which the writers shew an utter lack of power to reason correctly, up to approximate solutions the construction of which required much ingenuity on the part of their inventor. In some cases it requires an effort of sustained attention to find out the precise point in the demonstration at which the error occurs, or in which an approximate determination is made to do duty for a theoretically exact one. The psychology of the scientific crank is a subject with which the officials of every Scientific Society have some practical acquaintance. Every Scientific Society still receives from time to time communications from the circle squarer and the trisector of angles, who often make amusing attempts to disguise the real character of their essays. The solutions propounded by such persons usually involve some misunderstanding as to the nature of the conditions under which the problems are to be solved, and ignore the difference between an approximate construction and the solution of the ideal problem.

It is a common occurrence that such a person sends his solution to the authorities of a foreign University or Scientific Society, accompanied by a statement that the men of Science of the writer's own country have entered into a conspiracy to suppress his· work, owing to jealousy, and that he hopes to receive fairer treatment abroad. The statement is not infrequently accompanied with directions as to the forwarding of any prize of which the writer may be found worthy by the University or Scientific Society addressed, and usually indicates no lack of confidence that the bestowal of such a prize has been amply deserved as the fit reward for the final solution of a problem which has baffled the efforts of a great multitude of predecessors in all ages.... It is interesting to remark that, in the year 1775, the Paris Academy found it necessary to protect its officials against the waste of time and energy involved in examining the efforts of circle squarers. It passed a resolution, which appears in the Minutes of the Academy, that no more solutions were to be examined of the problems of the duplication of the cube, the trisection of the angle, the quadrature of the circle, and that the same resolution should apply to machines for exhibiting perpetual motion. An account of the reasons which led to the adoption of this resolution, drawn up by Condorcet, who was then the perpetual Secretary of the Academy, is appended. It is interesting to remark the strength of the conviction of Mathematicians that the solution of the problem is impossible, more than a century before an irrefutable proof of the correctness of that conviction was discovered.

Apparently the problem is insoluble because pi is a transcendental number, a fact which was proven in 1882. After this introduction, Professor Hobson proceeds, over hundreds of inadvertently Kafkaesque pages, to minutely detail every single failed attempt to solve this problem. One of the more exotic ones gave rise to this diagram:

Quantum Biology

This BBC report on quantum biology is about the most fascinating thing I've heard on the radio in ages.

Crime on the Decline Germany, Probably Because There's Less Lead Around

I've been following with fascination the debate in the U.S. about the relationship between crime rates and early childhood lead exposure. One of my favorite bloggers, Kevin Drum, recently wrote a fantastic piece for Mother Jones arguing that America saw dropping crimes rates in the 1990s in part because the U.S. banned leaded gasoline in the 1970s, saving an entire generation of children from exposure to lead, a fiercely potent neurotoxin which permanently lowers intelligence and disrupts impulse control in children. Read it here. Drum reports on reactions to the article and takes on critics here.

And now for Europe:

Here's the latest crime news from the Guardian:

There has been a surprise 8% drop in crime across England and Wales, according to official figures, suggesting the long-term decline in crime since the mid-1990s has resumed.

As near as I can tell, crime declines are always a surprise to the folks who look for answers solely in social trends. But Britain's continuing decline isn't a surprise to everyone. Europe adopted unleaded gasoline in the mid-80s, and EU countries all showed drops in lead emissions in subsequent years. In Britain, lead emissions began to decline about a decade later than the United States, but they made up some of that gap via a much steeper drop. So, to the extent that the crime decline is a function of less lead exposure among children, they're about five years or so behind us. This means they probably still have a few years of crime decline ahead of them.

So, you might be wondering, if Germany began seriously reducing lead emissions in the the mid-1980s, what impact might that have had on teenage criminality in the late 1990s, when children born in the mid-1980s became adolescents? Here's the relevant graph for Germany, from this source (g, .pdf):

The top line shows total criminality, the middle line criminality among German adolescents, and the bottom line among immigrants. Interesting, isn't it? The much smaller decrease you see among non-German offenders could well be explained by the fact that some percentage of them probably did not grow up in Germany.

Of course, the standard caveats apply that correlation is not causation, other factors are at work (especially the crime increase following reunification), etc.. But if you want to be convinced that lead exposure is a powerful (though, of course, not the only) explanatory factor, read Drum's piece -- and, more importantly, the studies it links to.

If this theory holds, it has to be one of the best pieces of news in a long time: because of a wise policy choice made decades ago, we will enjoy less crime -- and less of all the social ills and expense it causes -- for years to come. Kind of restores your faith in humanity, doesn't it?

Your Genes Determine Your Personality

I just sent off a saliva sample to 23andme to learn more about my genetic profile, and while I wait for the results, I've been continuing to look into the fascinating new discoveries about the influence of genes on personality traits. Over at Razib Khan's invaluable Gene Expression we find this table of heritability of particular personality traits (0.0 = no genetic influence; 1.0 = 100% determined by genes):

For comparison, your height is about 90% determined by your genetic makeup. By age 18, your genes determnine about 80% of your intelligence (it's hard to accurately test young children for intelligence, so the correlation increases as the test becomes more reliable and 'noise' decreases). Your genes also play a strong, if not determinative, role in your political orientation and personality structure. Of course, the headline of the post is misleading, I just gingered it up a bit to attract the attention of blank-slaters. As Khan aptly puts it: 'Biology may not be destiny, but it is definitely probability'.

One long-term trend we're seeing is the gradually increasing acceptance of findings such as these. There are still a few holdouts who, like global-warming skeptics, reject the findings out of hand, but their numbers are dwindling. I, for one, find it utterly fascinating. When I get my test results, I'll post anything interesting about them.

Cold Winters, Smart People

When people ask me (sometimes suspiciously, often incredulously) why I enjoy living in Germany, I tell them one of the reasons is that people here are just a little bit smarter than most other places I've lived.

This, as you might imagine, does little to allay the suspicion.Yet that's what I see every day: the bell curve just seems to be a bit farther to the right here in Northern Europe. There are many clues: the level of debate in televisions and radio talk shows is noticeably more sophisticated than in the U.S., where the average member of Congress now speaks with the vocabulary and grammatical sophistication of a 15-year-old, which is understandable, since they're trying to communicate with average Americans, whose English abilities are even worse than this. Northern European societies have also engaged in forms of sophisticated collective action -- mainly the creation of welfare states -- requiring judicious balancing of interests, sacrifice of present gain for future security, and a great deal of long-term thinking. Germans also behave quite sensibly -- they have all sorts of insurance, and live within their means. The more primitive kinds of religion (involving heavy superstition, unquestioning deference to authority, yet very little commitment to actual changes in daily conduct) are either unknown here or dying out. In the U.S., by contrast:

But, you ask, are these just idle musings, or are they backed by Science? Before you can ask whether certain areas of the world are cognitively blessed, you have to factor out a million potentially confounding factors, including level of development, composition of the population, etc. So this recent study (pdf) looked at haplogroups, genetic categories differentiating human populations which go back thousands of years and are considered particularly reliable indicators. The authors reviewed various theories of cognitive ability, including the so-called 'cold winters' theory, which posits that population groups which moved early into areas of the earth with long, cold winters developed higher cognitive abilities owing to the need to think ahead and plan for the future. There are other theories, but the authors sum them up as follows:

All these theories could be summarized under the general assumption that environmental challenges, both natural and social, which could be mastered by intelligence, will increase genotypic intelligence in the long run because phenotypically more intelligent members of the population historically had more surviving offspring. The requirements for this are that intelligence is at least modestly heritable, that there has been sufficient time in terms of generations for the frequencies of intelligence genes to have changed, and that increases in intelligence are non-prohibitive in terms of limitations imposed by brain metabolism, infant cranial size, and susceptibility to physical and mental diseases.

So the authors selected out a series of haplogroups that would be predicted to be associated with higher cognitive ability and tried to determine a correlation between countries in which those haplogroups were well-represented and intelligence. Here's the result:

So, societies in which more people came from Haplogroup A tended to be smarter. Germany is located somewhere in that cloud in the top center. It's not all genes, of course, the authors note that national IQ is heavily confounded with a country's level of development, meaning that a country's HDI ranking is still the best predictor of cognitive ability. Adequate nutrition, a functioning educational system, and a reasonably stable political order are hugely important. (We'll leave the obvious chicken-and-egg question to one side). But haplogroups, the authors conclude, 'also appear to be significant predictors of cognitive ability.' So, it turns out that cold winters may help explain why Northern European societies are so doggone stable and enlightened.

Homeopathy and the Transatlantic Culture Wars

Dr. Edzard Ernst, who says he was once sympathetic to homeopathy, describes his growing disillusionment:

Two main axioms constitute the core principles of homeopathy. The "like cures like" principle holds that, if a substance causes a symptom (e.g. onion makes my nose run), then that substance can cure a disease that is characterised by a runny nose (e.g. hayfever or a common cold). The second principle assumes that the serial dilution process used for homeopathic remedies renders them not less but more potent (hence homeopaths call this process "potentiation").

Both of these axioms fly in the face of science. If they were true, much of what we learned in physics and chemistry would be wrong. If anyone shows the concepts of homeopathy to be correct, he or she becomes a serious contender for one or two Nobel prizes. Homeopaths often say that we simply have not yet discovered how homeopathy works. The truth is that we know there is no conceivable scientific explanation that could possibly explain it.

Yet as a clinician almost 30 years ago, I was impressed with the results achieved by homeopathy. Many of my patients seemed to improve dramatically after receiving homeopathic treatment. How was this possible?

In order to understand this apparent contradiction, we have to take a step back and consider the complexities of the therapeutic response. Whenever a patient or a group of patients receive a medical treatment and subsequently experience improvements, we automatically assume that the improvement was caused by the intervention. This logical fallacy can be very misleading and has hindered progress in medicine for hundreds of years. Of course, it could be the treatment – but there are many other possibilities as well.

For instance, the condition could have improved on its own. Or the encounter between the therapist and the patient could have been therapeutic without any meaningful contribution from the treatment itself. Or the patient could have had high expectations in the treatment that prompted a powerful placebo response. Or the patient self-administered some other treatments concomitantly that caused the improvements. In other words, it is not the effect of the remedy per se, but the non-specific effect of the context in which it is given that benefits the patient.

...

About 200 clinical studies of homeopathic remedies are available to date. With that sort of number, one cannot be surprised that the results are not entirely uniform. It would be easy to cherry pick and select those findings that one happens to like (and some homeopaths do exactly that). Yet, if we want to know the truth, we need to consider the totality of this evidence and weigh it according to its scientific rigour. This approach is called a systematic review. Over a dozen systematic reviews of homeopathy have been published. Almost uniformly, they come to the conclusion that homeopathic remedies are not different from placebo.

So what's wrong with giving patients placebos?

• Placebo effects are notoriously unreliable; the patient who benefits today might not do so tomorrow. Placebo effects also tend to be small and short-lived.
• Knowingly giving a placebo to patients would be unethical in most instances. Either clinicians tell the truth (i.e. "this is a placebo"), in which case the effect is likely to disappear, or they do not, in which case they are liars.
• Giving a placebo to a patient with a serious condition that would be otherwise treatable does seriously endanger the health of that patient.

Back in the bad old days or cresting European anti-Americanism, from 2003-2006 or so, I was drawn into many tedious conversations about the supposed failings of the United States. For those times when I was unable to avoid these futile 'debates', I created a private catalog of comparable failings of German society. I still have that list somewhere, perhaps I should post it for old times' sake.

This almost always wrong-footed my conversation partner, proving the old adage that the best defense is a good offense. If I were feeling particularly didactic, I would try to conclude dialectically by observing that my goal wasn't something fatuous like proving one society generally 'better' than another, but to point out that an exclusive focus on the negative aspects of a foreign culture leads to unnecessary misunderstanding and resentments, blah blah blah.

One of the Europeans' favorite debating points was the hostility to science of 'the Americans': '40% of them don't believe in evolution, and lots of them also don't believe in global warming! What sort of religious craziness is driving this rejection of science?' My first return volley was, of course, homeopathy, a billion-dollar industry in Germany based on the crackpot theories of a nineteenth-century quack. Two-thirds (g) of Germans believe in it. As often as not, my conversation partner was a believer in homeopathy, and suddenly found himself in the unenviable position of critiquing American for its lack of faith in 'science' while simultaneously defending a theory of illness that's less scientific than the theory of humors.

I have to admit, it was sort of fun...

Now is the Time on Sprockets When We Experience Communicative Socialisation

The very German-looking Philip Oltermann (the glasses!) asks whether Germans just don't get social media because they, er, don't get communication in general:

When news magazine Focus announced this week that Germans were finally cottoning on to Twitter – the site reaching a record 3.5 million users – it was met with the digital equivalent of a shrug. One blogger suggested that Germans just don't know how to deal with social media:

"What they fundamentally do not see and get is the obvious, namely that Social Media is about communication. Communication/conversation is a dark hole in German culture. For Germans, talking first and foremost means conveying information. Conversation as a bonding agent in any form of interpersonal encounter is literally a non-starter in Germany. (If you've ever been to an awkward German office party where people have no problem with facing one another without saying a word for, oooh half an hour, you'll know what I mean.)"

Most Germans will recognise at least a grain of truth in that. Even back in the late 19th century, the sociologist Friedrich Tönnies wrote in despair about the German inability to get its head around the concept of an open and interactive Gesellschaft or society – tight-knit, closed-off Gemeinschaften or communities was apparently all they could do. Few young Germans still keep up the Stammtisch tradition, though small talk can still be a struggle. I recently attended a German conference in which the last item on the programme was billed as Kommunikatives Beisammensein, "communicative socialisation". Or, as people might call it in Britain, "going to the pub".

The rest of the article tries to add some caveats to the stereotype, in my view not very convincingly. Germans are just plain much more reticent and cautious about sharing information than Anglo-Saxons. Again, as with all national traits, this is a matter of averages and bell curves. The chart below, which I stole from some website, shows light orange as the standard normal distribution of 'communicativeness' (or 'chattiness') among Anglo-Saxons on the right, and among Germans on the left, in darker orange.

No, really, this is exactly what the chart shows! This is Science, people! In any event, if makes my point: although you can always find some German who's chattier than an American, the modal German is much more taciturn than the modal American. I think the Brits would fit just about in the middle, but I'm no expert there.

The Controversial Austrian Statesman's Mistress Had No Lady Parts

That is the contention of a new book about her by Prof. Thomas Lundmark, The Untold Story of Eva Braun: Her Life Beyond Hitler:

Thanks to the author’s 15 years of intensive research, we now know that Eva Braun was the product of a broken home, that her father was an alcoholic, and that she suffered from depression and Mayer-Rokitansky Syndrome or "MRKH," the congenital absence of a functioning vagina and uterus, a condition which affects one in every 4,000-5,000 women. Now, 65 years after Eva’s death, this book finally sets the record straight on Eva Braun.

FrogLev 2000

Andre Geim won the Nobel Prize in physics this year, for his work with graphene. Ten years ago, Geim won an IgNobel for using magnets to levitate a frog: