Natural selection in humans: the EPAS1 gene at high altitudes

June 24, 2010 • 5:58 am

At the Guardian Hay Festival in Wales, I was asked a question that almost always comes up when I speak in public: Is natural selection/evolution still operating in humans? From first principles we almost have to say “yes,” for if humans experience differential pre-reproductive mortality, or differences in reproductive output (which is true), and if some of those differences are affected by genes (as they almost certainly are), then selection will be operating.  But first principles are not enough: people want hard evidence for natural selection in our species.

The classic example of selection operating on humans—selection that’s certainly going on today—is that occurring in sickle-cell anemia, where a mutation in the beta chain of hemoglobin confers (in single dose) some protection against falciparum malaria. Individuals with one copy of the mutant gene have protection, but individuals with two copies have sickle-cell disease, which is invariably fatal. This kind of selection keeps the mutant gene present in appreciable frequencies in African populations.

A while back I cited a study suggesting that selection is operating on cholesterol, blood pressure, age at first reproduction, and other traits in modern humans.  A new study in PNAS by Cynthia Beall and 27 colleagues (reference below) gives evidence for selection in humans on another hemoglobin-related trait: adaptation to high altitude.

The reason this study has so many authors is because it’s really three independent (but related) studies agglomerated into one publication.  All the studies examine the region of the genome that contains the gene EPAS1, which encodes half of a transcription factor (a protein that regulates the expression of other genes).  Among its functions, the transcription factor helps control the production of red blood cells, increasing their number under low oxygen conditions (hypoxia).  This is a short-term adaptive response to living at high altitudes, but can also cause excessive production of red blood cells, leading to chronic mountain sickness that can kill people or reduce their reproduction.  Some mutations in EPAS1 that increase its expression, for instance, are associated with increased hypertension and stroke at low altitude, symptoms similar to that of mountain sickness.

These facts suggest that people living permanently at high altitudes might undergo selection at EPAS1 to reduce the fitness consequences of excessive red blood-cell production.  The three studies suggest that this is indeed the case:

  • Genome-wide comparisons of high-altitude Chinese (Tibetan) populations with related but low-altitude Han Chinese populations show 8 DNA regions that are highly differentiated between them. All eight are in the EPAS1 region.  This suggests (but of course does not prove) natural selection differentiating this region between the populations.
  • An association study showed a relationship between EPAS1 sequence and hemoglobin concentration in Chinese Tibetans.  In all cases, the DNA sequences in higher frequency were associated with lower hemoglobin titer.
  • This association study was replicated in another sample of Chinese Tibetans, with similar results: individuals having the DNA variants in highest frequency showed the lowest hemoglobin concentration.

These are suggestive results, made stronger because differentiation in this region was predicted from knowing the function of the DNA.  But the results are not conclusive. EPAS1 helps regulate at least a hundred genes, and perhaps selection is acting not on hemoglobin concentration, but something else.  Indeed, an earlier study of Andean populations compared to lowland ones showed no sign of selection at EPAS1.  (Perhaps there is a specific Tibetan mutation for resistance to mountain sickness that is not present in the Andes.)  A more conclusive result would be to follow individuals of known genetic constitution at EPAS1 throughout their life, seeing if differential survival or reproduction is associated with specific mutations at that gene.

If the results do stand up (and I find them fairly convincing), we’d have a nice demonstration of selection acting in our species over a short period of time.  Despite our technological and medical advances, we are not immune to Darwinian natural selection so long as people continue to die before they stop reproducing, or have different numbers of offspring, and so long as this differential mortality/reproduction is associated with genetic differences between individuals.  It will be a long time, if ever, before we free ourselves from the kind of selection that acts on all other species.

________

Beall, C. M. et al.  2010.  Natural selection in EPAS1 (HIF2α) associated with low hemoglobin concentration in Tibetan highlanders.  Proc. Nat. Acad. Sci. USA 107:11459-11464

Go USA!

June 23, 2010 • 6:46 am

We will beat Algeria cuz we haz extra help!

HALFTIME:  tie 0-0.  If we tie, we’re out of the tournament.

GOOAAAAAAAALLLLLLLLLLLLLLLLL!  Helped by the kitteh, a dramatic win for USA in minute 91!

Here’s the last-minute winning goal by Landon Donovan:

Oil endagers oil-seep communities

June 22, 2010 • 9:11 am

Ironically, although the BP oil spill threatens ecological communities in and around the Gulf of Mexico, some of those communities are themselves based on natural oil and gas seeps.  As today’s New York Times reports, there may be thousands of these ecosystems in the deep sea (up to 1.5 miles down), all based on chemosynthetic bacteria feeding on methane and hydrogen sulfide associated with gas seeps.  In this sense they resemble hydrothermal vent communities, except that the temperature of the Gulf communities is lower and the bacteria feed on petrochemical products rather than dissolved minerals.

The Times article has a good slide show with photographs of some of the Gulf communities, which include molluscs, corals, and tubeworms:

Black coral in a cold-water seep:

A one-sided “dialogue”

June 22, 2010 • 6:09 am

A recent post at The Intersection has praised the one-sided dialogue on faith and science recently sponsored by The American Association for the Advancement of Science (and funded, of course, by Templeton).  Scientists, so the post says, should approach the faithful with humility, because, after all, even though the tenets of faith are wrong (the author is an atheist), it can offer consolation in time of trouble.  Because of this, we should refrain from not only trying to convert the faithful, but from criticizing their faith at all:

Still, surely the New Atheists must on some level recognize the critical importance religion plays in many people’s lives–which implies that we can hardly expect believers to discard their faith based on philosophical considerations, no matter how persuasive these may seem to many secularists or scientists.

At the AAAS event, the pastor David Anderson told an unforgettable story underscoring this point–the story of a single mother who just lost her husband, and has two poorly behaved kids, disciplinary problems who keep getting in trouble at school. Does this woman care about the latest scientific discoveries about, say, asteroids? No, explained Anderson, “because an asteroid has just hit her family.”

Science, alone, is no consolation in this context. Religion gives this single mother something she can lean on. Religion, explained Anderson, provides one with inspiration, whereas science provides information (and science fiction provides entertainment).

So how do you get into true dialogue with religious believers when you’re coming from the scientific perspective? Once again, Anderson had an answer. He said his church would certainly welcome scientists who wanted to come and visit, and talk to the attendees–and added that many churches, and many pastors, feel the same way.

But, Anderson added, that will not be the case if the scientists show up wanting to convert, or deconvert, or debunk, or whatever.  Or if they give off an air of superiority, the sense that they are smarter than everybody else. That won’t fly. It will shut down dialogue, rather than encouraging it.

It is not only in the science-religion context, of course, that humility is called for, and where superiority is counterproductive. The same is true of any dialogue, almost by definition. But again, that shouldn’t be a problem for science–is not the scientific method itself fundamentally based on a kind of humility before nature?

I think it shows far more respect for the faithful to engage their arguments honestly and openly than to pat them on the back and say, “There, there—even though I don’t share your beliefs I won’t risk upsetting you by questioning them.”  But Mooney’s post is not about any kind of constructive dialogue.  How could it be, if one side is forbidden to have its say?  The post is about why scientists should give more respect to religion.

Further, the claim that “we can hardly expect believers to discard their faith based on philosophical considerations, no matter how persuasive these may seem to many secularists or scientists,” is ridiculous, of course.  This is a deliberate distortion in service of the notion that, despite the claims of those horrid New Atheists, science and faith are compatible.

There are in fact many, many people who have discarded their faith because its tenets were either philosophically insupportable or came into direct conflict with the palpable facts about the world.  You know many of these folks, who include Dan Barker, Russell Blackford, all the preachers who, as documented by Dennett and LaScola, lost their faith, and many commenters on this website (chime in if you’re one of them).

And me.  As Jeremy Manier wrote a while back in The Chicago Tribune, I was brought up in a Jewish household believing in God, and accepted His existence without question, until, in 1967, I suddenly realized that there was no evidence for any of the claims of faith and became an instant atheist. It literally happened in a few minutes.

Yes, it may be too much to expect most religious people, steeped in faith from birth, to reject religion.  But there are the children, too.  Keep them from being brainwashed, and see how many voluntarily choose faith over atheism when they reach majority.  I would guess that if religious brainwashing of children were prohibited, atheism would increase drastically within a generation.  The vast majority of people are religious not because they chose their faith voluntarily—because it made more sense than other faiths—but simply because they were brought up that way.  It is not too harsh to call this brainwashing.

To those who say, “Religion will be with us always,” I respond, “Look at Europe.”

Speaking of converts to atheism, many of us know of Eric MacDonald from his posts on this and other websites.  He was once an Anglican priest, but now writes eloquently of the problems with religion. One of his posts, which I want to highlight here, appears in a good discussion of the Intersection post at Butterflies and Wheels:

This is bizarre! What is the matter with that man?! [Chris Mooney, author of The Intersection post]. He may be an expert at communication, but all he seems able to communicate — and he does it well — is his own lack of understanding, his resolute inability to understand what anyone else is saying.

One of the things that bothers me more than anything in the absurd assumption that is being made when people talk about the compatibility of religion and science is the sheer diversity, and, so often, perversity, of religious belief. Religions come in so many different shapes and sizes, that the claim that religion is consistent with science is almost certainly false for most religions and for most religious beliefs. If the claim is being made that practicing a kind of cumulus shaped spirituality, without any clear ontological commitments, is consistent with doing science, then, of course the answer is, yes, there is no problem. You can even do it and take an interest in collecting match boxes. But if the religious belief happens to be that someone, somewhere, has authority to speak in the name of a transcendent being for which there is no evidence, that this transcendent being speaks to and communes with, human beings, that it has made an appearance in various guises in the world, that it causes miracles to happen and bodies to rise, or brings luck and good fortune to the favoured, punishes the wicked (for any given religious definition of what that word mean ins its various religious iterations) and authorises outrageous immoralities and injustices in its name, then it is not compatible, and it fatuous to suggest otherwise. Nor is there room for dialogue with this sort of thing. Until people start to recognise that when they speak about religion they are not speaking only about the nice people in the church across the street, who seem so culturally warm and fuzzy, and probably pretty fuzzy minded too about what their beliefs imply, they are also speaking of pretty distressing forms of belief and the injustices and inhumanities that flow from then. And just repeating some slogan about the compatibility of religion and science does a great disservice, not only to science, but to the victims of so much religion.

For, religion, despite all the warm and fuzzy notions that it seems to connote for so many people, is not warm and fuzzy. It misleads and misdirects. It abuses children, not only by deforming their lives with physical and emotional and sexual abuse, but by much of the religion that is taught, which is of an incredibly destructive sort, very often indelibly so. It ruins lives and imaginations, it binds them to forms of thinking that are the product of ancient cultures, when people banded together on the side of their god against others on the side of theirs, and while it may have given them protection, it also required their submission and all the hatreds that are born of it. This is still being demanded. There is no other way to teach religion. It is a form of authoritarianism, and even those who attempt to convey a more humane, even secular form of religious thought, will be constantly undermined by people who, in faithfulness to tradition, return people to the faith once delivered to the saints, or whatever group happened to be first and therefore the model of faithfulness.

And it is really tiresome that someone like Chris Mooney, who obviously knows nothing whatsoever about religion and its claims, continues to blight the world with his assinine slurs that he vainly makes about an imagined group of people whom he calls the New Atheists, without any understanding of them either. (He seems a remarkably uninformed person.) I say we adopt the name, because it’s a good way of making a distinction between people who think that religious believers have something to contribute to the future of the world other than theocracy and injustice, and those who think that religion has had its chance, and needs now to be opposed in the name of more effective ways of knowing about and changing the world. The trouble with Chris Mooney is that he really doesn’t know about religion or atheism. And that’s why he can’t have a dialogue, but I have read so much good stuff on Jerry Coyne’s site, here on B&W and on Pharyngula and Dawkins.net, etc., that really is dialogue, and he’s not paying attention. But I suspect that, even if he was, he would not be able to understand. That’s the difference between someone who knows about framing, and those others who know how to put something in the frame.

Russell Blackford has also highlighted this post at Metamagician.  Go visit B&W for more good discussion of compatibility.

Were Adam and Eve real?

June 21, 2010 • 6:07 am

Over at the Templeton-funded BioLogos website there has been a lot of discussion about the historicity of Adam and Eve.  This is a problem because scripture claims these two were the progenitors of humanity, but genetics says otherwise.  It’s simply not true that all of humanity’s DNA traces back to a pair of individuals who lived no more than 10,000 years ago; indeed, the different bits of our DNA trace back to different ancestors who lived at different times. What’s clear is that our ancestors were in a population of humans, some of whom left Africa around 60,000 years ago, and virtually all of modern human DNA comes from that population, which itself descended from African ancestors who split off about 6 million years ago from the ancestors of modern chimps.

For some reason the biological data have caused a kerfuffle at BioLogos.  One would think that if these folks are really devoted to reconciling science and Christianity, they’d do for Adam and Eve what they did for Genesis: claim that this is just a metaphor rather than the literal truth, and the literal interpretation is theologically misguided.  Adam and Eve simply stood for our ancestors, just as Smokey the Bear stands for all wild bears. (No matter that for centuries Christians wrongly assumed what the Bible says plainly:  Adam and Eve were the two God-created ancestors of all humanity.)

But the kerfuffle goes on, because some Christians, despite the biological data, want to see Adam and Eve as real people.  The latest attempt to reconcile genetics with Genesis comes from Daniel Harrell, described at BioLogos as

the Senior Minister of Colonial Church in Edina, Minnesota. Before stepping into this role, Harrell served as associate minister at Park Street Church in Boston, Massachusetts for over twenty years. He is the author of the book Nature’s Witness: How Evolution Can Inspire Faith, and is author of the forthcoming book How To Be Perfect: One Church’s Experiment with Living the Book of Leviticus.

Introducing Harrell’s essay, “Adam and Eve: Literal or Literary?”, BioLogos states its own position:

As many of our readers know, the historicity of Adam and Eve is a critically important topic in the discussion of Christianity and human origins. Although BioLogos takes a firm stand on the fact that Adam and Eve could not have been the sole biological progenitors of all humans (see here), science does not rule out the possibility of a historical Adam and Eve, which opens this interesting discussion.

Here’s why Harrell sees the question of Adam and Eve as crucial:

If they are literary people, then that raises questions about the rest of the Biblical cast. Are Moses and Jesus fictional characters too?

Well, yes, but this is exactly what happens when you see parts of the Bible (like Genesis) as metaphorical, and other parts as literal, with no good way (except for post facto attempts to harmonize them with science) to tell which is which.

Harrell goes on:

If they are literal people, then the trove of evolutionary and DNA evidence can’t be right. It’s impossible for the human race to trace back to a single pair of parents (and this without mentioning a talking snake and God creating Adam out of the dirt and Eve from his rib). For the serious student of Scripture and science, making a choice between literal and literary is impossible too. Can’t there be a middle option?

Perhaps.

But if the talking snake is obviously metaphorical, why isn’t the talking Moses?  Anyway, Harrell offers two solutions.  The first involves apparent age:  God created Adam and Eve with DNA that made them look older than they really were:

The first is that God created them supernaturally, midstream in evolution’s flow. To create in such a way would require that God also put in place a DNA history, since human origins genetically trace back to earlier, common ancestors. Conceptually, this presents the same problems as creating the universe with apparent age. Apparent age is how some square a literal Genesis with scientific evidence. Stars that appear to be billions of years old (according to cosmological measurements) are in reality only a few thousand years old (according to literal biblical reckoning). God created the stars with age.

Now I know what you’re saying: Harrell will reject this hypothesis because it’s simply silly.  Such a proposition violates all the methodological naturalism that underpins the progress of science.  And it makes God look duplicitous, which Harrell recognizes:

The problem is that creating with age makes God seem to be tricking us into thinking things are older than they are with no clear reason for doing so.

But he doesn‘t reject this!  Harrell leaves it as an open possibility for Christian believers:

Nevertheless, given that Adam and Eve are both introduced in Genesis, presumably as adults rather than children (even if they acted like children), it could be that in their case, creating with age (and a history) would apply. While we might not necessarily understand why God would do that, he could do that (being God and all).

Yes, of course, God could do anything, including creating the light from stars in transit to Earth.  We just know that God is omnipotent and loving and forgiving, but as for why he does stuff, well, ours is not to reason why.

That is all Harrell says about this possibility.  The other option is to see Adam and Eve as real people, but only as two members of the human species specially anointed by God:

Another option might be to have Adam and Eve exist as first among Homo sapiens, specially chosen by God as representatives for a relationship with him. We often speak of Adam theologically as serving as representative of humanity in matters of original sin (his sin affects us all; Romans 5:12), so the idea of Adam as representative already exists in Christian theology. . . .

An advantage of this interpretation is that God’s natural processes marvelously work without the need for any ancestral or genetic fabrication. Also, you’d finally be able to explain where it is that Cain found his wife (answer: from the other humans walking the earth east of Eden; Genesis 4:16-17).

But why do we need to see Cain as a literal person too?

This second option, however, also requires a bit of exegetical fiddling:

However, this view would require a reinterpretation of words like “formed” and “breathed into his nostrils the breath of life” (Genesis 2:7 KJV). Can we use “formed” and “breathed” to mean created through the long and continuous history of biological evolution (as were the other living creatures in Genesis 1)? If so, then perhaps “the Lord God formed the man” could be read emphasizing the novelty and uniqueness which humans inhabit.

Similarly, the “breath of life” would not signify simply oxygenated animation (surely Genesis isn’t simply speaking in that sense), but that breath which set humans apart as inspired by God (the Hebrew word for breath here is different than the word used for oxygen-intake by living creatures as a whole).

And it requires that God (who presumably wrote the Bible) knew that He was giving a poetic description of evolution:

There are those who would object to such a reading since the Biblical author would not have had knowledge of evolutionary biology. And yet just because the author of Genesis wasn’t a scientist doesn’t mean that evolution wasn’t happening. We still describe babies’ births as “miracles” even though they’re among the most natural occurrences in nature.

But if we evolved, then we’re just like chimps, tigers, and sunflowers, right?  And that can’t be the case, because the Bible says we’re the special objects of God’s creation.  Harrell’s answer:

Whether specially created or specially selected, humans constitute an interruption in the evolutionary process. Before people showed up, evolution’s potential pathways were invisible. But once humans appear, human volition entered with it. The human capacity to choose replaced randomness with intentionality. We have developed enough mastery over our environment (Genesis 1:28) that natural selection, in the strict Darwinian sense, no longer really applies to us.

Never mind the insupportable statement that natural selection no longer applies to us—a silly assertion that is instantly refuted by the case of sickle-cell anemia in Africa.  What is ridiculous here is the tortuous lengths to which Harrell—and other writers at BioLogos—go to preserve the historicity of Adam and Eve.  If God dictated the Bible, and gave the Genesis account as simply a metaphor for evolution (presumably an idea that was beyond the ken of Middle Eastern goatherds two millennia ago), then why couldn’t he have made up Adam and Eve as a metaphor for the human branch of the evolutionary tree?

And what about Harrell’s suggested “apparent age” theory—that Adam and Eve were poofed into being with DNA that made them look as if they descended from a far older population?  Does that not violate any notion of scientific methodology and truth?  And why would God do that, anyway?  To fool modern scientists? And if we buy apparent age for Adam and Eve, why not for fossils? After all, God could have created a proportion of radiometric elements in the soil that would make nearby fossils look old even if they were really put in the earth a few thousand years ago. If you accept apparent age to save the Bible, where does it stop?

More important: isn’t BioLogos embarrassed to have this kind of stuff on its website, which purports to accept the findings of science?

BioLogos doesn’t realize that this kind of desperate apologetics makes  believers look pretty bad, at least to those who have any respect for truth.  It’s far simpler to just see Adam and Eve as metaphors, since there’s not a scintilla of evidence that they ever existed.  But of course if you start rejecting silly notions because there’s no evidence for them, most of scripture goes down the drain.

Holiday snaps: art and science in Wales

June 19, 2010 • 2:52 pm

I was invited to the Guardian Hay Literary Festival, held annually in the small town of Hay-On-Wye on the English-Welsh border.  It’s a lovely bucolic place, and, with 29 bookshops, a Mecca for bibliophiles—ergo the festival.

My own event consisted of a one-hour conversation with the British writer Rosie Boycott, but some of the best parts of the festival were all the freebies associated with speaking.  These included flights to the UK and back, free tickets to all the events (the nicest perk), a case of champagne, free car transportation anywhere I wanted to go, free food, and, of course, a nice stay in a B&B, in this case the Rhydspence Inn, a 14th-century building:

I went to as many events as I could.  A nice one was the wine lecture and tasting by Simon Hoggart, wine writer for The Spectator and political columnist for the Guardian.  Hoggart is shown below with the four wines we tried—a viognier, a Ribiera del Duero, a St. Joseph, and an albariño.  Two of these were very good, and Hoggart punctuated the tastings with wry and ascerbic observations about the wine world.  (I am still a bit appalled, though, to see how often Brits will publicly make fun of the French.  It’s a reliable way to get a laugh in old Blighty, but it’s pretty chauvinistic. I’ve seen it at academic talks, too.)


Here’s one of my literary heroes, playwright Tom Stoppard, giving an introduction to a Max Hastings, who in turn delivered a superb talk about his new book on Winston Churchill.

A day before my own talk, I was asked by festival director Peter Florence to fill in for Philip Pullman, who was ill, as part of an impromptu series of short talks for charity.  I agreed, though I was a bit freaked out by having only a few hours to write a short talk on a subject of my own choosing.  But I was even more freaked out when I saw the line-up for that event:

OMG, Tom Stoppard!  This was clearly to be the apogee of my life.  But, with my polo shirt and blue jeans, I wasn’t dressed properly.  I quickly asked my friend Steve Jones if I could borrow his jacket.  Here we are with his jacket, which was made for him by a tailor in India.  The label says, “Specially made for Prof. Steve Jones.”

At the gala, I talked for about 12 minutes on evolution, science, rationality, and atheism; it seemed to go down well.  After the talk Stoppard detained me and noted that I had been unfair to claim, as I had in my talk, that religion was the major reason why many people opposed evolution.  Another important reason, he argued, was that evolution simply could not explain some phenomena.  When I asked him which ones, he said, “Consciousness.”

Over the next day and a half we continued this conversation, with me trying to persuade The Great Man that while evolutionary biologists had not yet provided a definitive natural-selection scenario for the evolution of consciousness, scientists were busily and successfully showing that consciousness was a material phenomenon, and that this was the first step in understanding its evolution.

I’m not at all sure that TGM had a real beef with evolution (after all, Stoppard is our most science-friendly playwright), and in the end I suppose that he regarded as the big mystery not consciousness itself, but the ability of the consciousness to crank out things like Arcadia or Rosencrantz and Guildenstern are Dead.

Stephen Fry (left) at Hay.  Like Stoppard, he is TALL:

From Hay-on-Wye we repaired to Laugharne for a few quiet days on the Welsh coast.  Laugharne, a sleepy town on an estuary, is famous as the final home of poet Dylan Thomas and the place where he’s buried.

I am a huge fan of Thomas, whom I regard as one of the three best anglophone poets of the twentieth century (the others being Yeats and Eliot).  Most of you probably know at least one of his poems (“Do not go gentle into that good night” is the most famous), and may be aware that he was an alcoholic womanizer who died at 39 in New York.  He had a tempestuous relationship with his wife Caitlin; here’s the couple in a more peaceful moment:

When not travelling (Thomas made frequent poetry-reading trips to America to earn money), he spent the last four years of his life at The Boat House in Laugharne, a lovely place overlooking the estuary.  It was purchased for Thomas by a patron.

Here he wrote many of his finest works, including the wonderful “play for voices” Under Milk Wood, and the poems “Do not go gentle. . ” and “Poem on his birthday.”  (If you have not read the play, by all means do so.  Better yet, get hold of the Caedmon recording that Thomas and colleagues made in 1953.)

These pieces were composed in “the writing shed”, a very small room that was the previous occupant’s garage.  It’s been left exactly as it was when Thomas occupied it:

Interior of the writing shed:

Holy relics:  Thomas’s drawing of a boat

and his only pair of cufflinks.

Here’s the local paper’s announcement of Thomas’s burial in Laugharne (click to enlarge).  Note that it gets far less space than an announcement of the burial of two local toffs:

Thomas’s grave, in the burial ground of St. Martin’s Church, is touching: it’s a simple wooden cross, the only one among the gravestones.  Catlin was later buried beside him; her name is on the other side of the cross.  (The only other grave I’ve seen that is so poignantly austere is that of Vincent Van Gogh, buried next to his beloved brother.)

h/t: Otter

Caturday felid: The cat came back

June 19, 2010 • 8:16 am

If any cat song is a meme, this is.  I defy you to listen to it and not have it return to haunt you.  First up is a bluesy rendition by children’s singer Laurie Berkner:

The song was written by Harry S. Miller in 1893, and has mercifully been purged of its original racist overtones.  Wikipedia has a big entry on it, including the following:

The song is often used to teach children the concepts of rhythm and tempo. It is an excellent example in this regard, because of the strong and consistent beat pattern, combined with amusing and humorous lyrics. Additionally, especially the minor key versions of the song, have a compelling effect with regards to perception of tempo.

Like many children’s songs, the song has a very strong well-defined beat pattern. It consists of one weak beat, one strong beat, so it is often sung in 2/4 time.

Thus it can be (and often is) sung while walking, with, for example, strong beats when the left foot hits the ground and weak beats when the right foot hits the ground.

If the song goes viral in your brain, let us know.

The Cat Came Back is also the subject of a short, award-winning Canadian animation (nominated for an Oscar, too):

[vodpod id=ExternalVideo.950734&w=425&h=350&fv=mGatewayURL%3Dhttp%3A%2F%2Fwww.nfb.ca%2Fgwplayer%2F%26mID%3DIDOBJ260%26bufferTime%3D15%E2%8C%A9%3Den%E2%84%91%3Dhttp%3A%2F%2Fmedia1.nfb.ca%2Fmedias%2Fnfb_tube%2Fthumbs_large%2F2009%2FThe-Cat-Came-Back_big.jpg%26width%3D516%26height%3D337%26bookmarksURL%3Dhttp%3A%2F%2Fwww.nfb.ca%2Fremote%2Fget_bookmarks%2Fthe-cat-came-back%2F%26getPlaylistOnEnd%3Dtrue%26playlist_id%3DREL260%26showWarningMessages%3Dfalse%26enableJavascriptAPI%3Dtrue]

Another nice version sung by Rowlf from Sesame Street.  Check out that bedraggled puss!

NYT reviews Hitch-22

June 19, 2010 • 5:53 am

I know I said that I wouldn’t post on this book again, but I’m adding one more link to tomorrow’s New York Times review of Hitchens’s memoir.  I think the review is absolutely fair, and perhaps the best of the many I’ve read.  One plaint:  reviewer Jennifer Senior says that Hitchens “writes like a drunken angel.”  If the “drunken” refers to the man’s well known predilection for the grain and the grape, I think the word is wrong, for there’s simply no trace of drunkenness in Hitchens’s writing.  He writes like an angel, period.  But perhaps Senior simply means that drunken angels write better than sober ones.

And it turns out that much of the autobiographical pith of “Hitch-22” has appeared elsewhere, most notably in Ian Parker’s excellent 2006 profile of Hitchens in The New Yorker [note: link here], and it’s surprising how little to it that Hitchens now adds — how little, indeed, is in this book that’s generally considered the lymph and marrow of a traditional reminiscence. We hear almost nothing of Hitchens’s two marriages or three children, and he certainly never discusses falling in love. (Though he talks about his experiments on the Wilde side at university — as well as at boarding school, even if those were abruptly brought to an end by a snitch “with the unimprovable name of Peter Raper.”) We do hear about his social life and dearest friendships, and those portraits and set pieces are some of the most pleasurable in the book. This is a man who’s cut such a fat swath through the smart set that a dinner with William Styron essentially gets relegated to a footnote, as does the revelation that he learned the identity of Deep Throat long before the public did, by pestering Nora Ephron, Carl Bernstein’s ex-wife (in fact, you would not believe the number of delectable footnotes in this book; the devil, apparently, is in the asterisks). . . .

None of this means that “Hitch-22” isn’t marvelous in its own way. But it’s probably a misnomer to call it a memoir, and easier to enjoy if one thinks of it as a collection of essays instead. . .

By the time he got to Oxford, he was quite accustomed to “keeping two sets of books,” passing out leaflets at car plants by day and racing off in fancier dress to the Gridiron Club by night. When he began his work at The New Statesman, he realized that “journalism was the ideal profession for someone like myself who was drawn to the Janus-faced mode of life,” in that one had to seduce both sides to hear the whole story.

So yes, Christopher Hitchens may long to be a cogent man of reason, and he can certainly be a pitiless adversary. But he knows there are two sides to any decent match, and it’s touching, in “Hitch-22,” to see how often he’ll race to the other side of the court to return his own serve. Which may explain why, though he tries to be difficult, he’s so hard to dislike.