Happy Darwin Day!

February 12, 2012 • 5:45 am

203 years ago today, Charles Darwin was born in a manger in Shrewsbury, England, the son of a wealthy doctor and an heiress from the Wedgwood china firm.   Although he’s most famous for On the Origin of Species—and let’s recall the full title, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life—Darwin wrote about a dozen other books, covering subjects as diverse as earthworms, orchids, climbing plants, sexual selection, and, of course, the evolution of humans and our emotions.

The man was a polymath, and did all this despite a debilitating illness whose nature is still unidentified.  It didn’t hurt, though, that he was independently wealthy, for his wife Emma was also a Wedgwood heiress (she was his first cousin, a union that was and is legal in the UK but is considered incest in some American states.)

Darwin at 51, the year after he published The Origin

I reread The Origin about once a year (only the first edition, which gives the full flavor of its revolutionary ideas), and still consider it the best science book ever written. My ranking is not based on its prose, which in some places is lovely (Voyage of the Beagle is better), but on its lucidity and, above all, its marvelous synthesis of diverse and previously unexplained observations about nature into a coherent hypothesis of evolution, as well as the proposal of a novel mechanism (natural selection) to explain adaptive evolution. It’s a work of sheer genius.  Here’s my dog-eared copy, which is about to give up the ghost:

And some of the notes I’ve made over the years, showing how Darwin anticipated modern evolutionary ideas, including punctuated equilibrium and kin selection:

I’ve always been surprised at how few biologists—even evolutionary biologists—have read The Origin, but I’m sympathetic, for it’s not a light read and some find the Victorian prose off-putting. I used to require it for my undergraduate class, but the students objected so vehemently that it’s no longer on the syllabus (mea culpa).

So here’s my question for readers, and answer it honestly:

Have you read The Origin in its entirety? If not, why not? If so, did it have a big impact on you?

By way of tribute, let’s revisit the famous last paragraph, which by now is so familiar that it’s almost trite.  But it’s still lovely and full of interesting bits, including the comparison of the law of gravity with an implicit “law” of natural selection, the idea of the “higher animals” as the most exalted production of nature, the suggestion that the first organism had life “breathed into it” (scholars have, of course, debated whether this was a suggestion about God), and the only use of the word “evolve” in the entire book!

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

Of course Darwin wasn’t always correct (he got the mechanism of inheritance wrong, for instance): he was a man, not a god. And evolutionary theory has moved on far beyond Darwin. But he got it right where it counted, and what I see as the five parts of Darwin’s evolutionary theory, all appearing in The Origin, remain parts of modern evolutionary biology, sometimes called “neo-Darwinism”:

  • The idea of evolution itself: the transformation of populations
  • The idea that evolution was gradual rather than instantaneous, involving the replacement of types in populations through differential reproduction rather than through change of the individuals themselves
  • The idea that all species have common ancestors, however dissimilar they are
  • The idea of a branching tree of life, whereby one original species gave rise to all of life’s diversity today (this is simply the flip side of common ancestry)
  • The idea that adaptive evolution is the result of a blind, and mindless process: natural selection, which accounts for the appearance of “design” that was previously imputed to the wisdom of God.

And since this website is about atheism and science, let’s remember that natural selection was the greatest God-killing idea of all time.  As Richard Dawkins has said, and rightly so, Darwin (and especially natural selection) made it intellectually respectable to be an atheist.

FREEBIE UPDATE:  Alert reader Chris notes that the U.S. National Academy of Sciences is offering free downloads of some of its evolution books for Darwin Day. This offer, here, is apparently only valid for today.


HuffPo Science section engages in dishonest quote mining

February 11, 2012 • 9:58 am

The HuffPo Science section can’t seem to keep its mitts off religion. Why on earth do they keep dragging God into that section?

The latest theistic incursion is a “slide show” called “Science and religion quotes: what the world’s greatest scientists say about God.”  There are 21 quotes, each accompanied by a photo of the scientist, and, to be fair, there’s a mixture of atheist and pro-religion statements.  A few of them, however, seem unfair to me, since the scientists at issue were clearly atheistic or agnostic in other, unquoted statements.

Carl Sagan:

“Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light-years and in the passage of ages, when we grasp the intricacy, beauty, and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual…The notion that science and spirituality are somehow mutually exclusive does a disservice to both.”

Okay, but this isn’t about God or religion, it’s about awe before the universe. By interpolating it in a post dealing with what scientists say about religion and God, HuffPo is Pulling An Ecklund, a neologism that I coyned to mean “a maneuver to bolster religion by including secular ‘spirituality’ within its ambit.” And of course it’s well known that Sagan was an atheist.  Here’s another quote, from Broca’s Brain, that they could have used (see quote #26 on the link, about an end-of-the-world prediction by religion):

“But religions are tough. Either they make no contentions which are subject to disproof or they quickly redesign doctrine after disproof. The fact that religions can be so shamelessly dishonest, so contemptuous of the intelligence of their adherents, and still flourish does not speak very well for the tough- mindedness of the believers. But it does indicate, if a demonstration was needed, that near the core of the religious experience is something remarkably resistant to rational inquiry.”

Albert Einstein:

“Everyone who is seriously involved in the pursuit of science becomes convinced that a spirit is manifest in the laws of the universe – a spirit vastly superior to that of man, and one in the face of which we with our modest powers must feel humble. In this way the pursuit of science leads to a religious feeling of a special sort, which is indeed quite different from the religiosity of someone more naive.”

Once more the old man is co-opted in the cause of God.  Einstein clearly didn’t believe in a personal God, and said so many times.  He called himself an agnostic, but I think he was, like David Attenborough, just a nonbeliever who didn’t like the term “atheist.”  They could, for instance, have used this quote from Einstein:

“The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish. No interpretation no matter how subtle can (for me) change this. These subtilised interpretations are highly manifold according to their nature and have almost nothing to do with the original text.”

or this one, in reply to an atheist who was worried about news reports that Einstein was conventionally religious:

“It was, of course, a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.”

But the worst one is this:

Charles Darwin:

“The impossibility of conceiving that this grand and wondrous universe, with our conscious selves, arose through chance, seems to me the chief argument for 
the existence of God.”

If you know anything about Darwin, you’ll smell this quote as fishy.  It reeks of being ripped out of context, just as creationists misuse Darwin’s quote about the absurdity of assuming that the eye could have evolved. Darwin was a nonbeliever: an agnostic at best, perhaps even an atheist.  So let’s look at this quote in context. According to the Darwin Correspondence Project, it’s from a letter written by Darwin to N. D. Doedes on April 2, 1873.  Here’s the whole letter, with the entire discussion in bold (the part quoted in HuffPo is underlined)

Dear Sir

I am much obliged for the photograph of yourself and friend.I am sure that you will excuse my writing at length, when I tell you that I have long been much out of health, and am now staying away from my home for rest. It is impossible to answer your question briefly; and I am not sure that I could do so, even if I wrote at some length. But I may say that the impossibility of conceiving that this grand and wondrous universe, with our conscious selves, arose through chance, seems to me the chief argument for the existence of God; but whether this is an argument of real value, I have never been able to decide. I am aware that if we admit a first cause, the mind still craves to know whence it came and how it arose. Nor can I overlook the difficulty from the immense amount of suffering through the world. I am, also, induced to defer to a certain extent to the judgment of the many able men who have fully believed in God; but here again I see how poor an argument this is. The safest conclusion seems to be that the whole subject is beyond the scope of man’s intellect; but man can do his duty.

With my best wishes for your success in life, I remain, dear Sir, | Yours faithfully | Ch. Darwin.

Note how not only the introduction to the quote is omitted, but, crucially, the quote given by HuffPo ends in a period, but Darwin goes on to question the very argument for God’s existence!  The semicolon and part after it is simply omitted.  And note how he brings in the existence of suffering as a counterbalance to God’s existence. This is classical Darwin, trying to avoid overt atheism without signing on to the idea of a personal God, or even a benevolent one.  When pressed, Darwin always punted and averred that it’s beyond our powers to judge. He was, like Attenborough, not fond of confrontation, especially about the idea of God.  His wife was religious, of course, and he also worried about religious opposition to his great ideas of evolution and natural selection.

HuffPo has simply done what creationists do: mined a Darwin quote to make it seem as if he believed in God.  It’s ridiculous, and whoever put those quotes together should be admonished. I’ll inform the editor of the science section, but I doubt that they’ll make any changes.

Accommodationism Weekend

February 11, 2012 • 6:48 am

Charles Darwin was born on February 12, 1809—all of you should know by now that that is also the day on which Abraham Lincoln was born—and biologists always mark Darwin’s birthday, often with a “Darwin Day” featuring evolution-related lectures.

One of the celebrations is “Evolution Weekend,” created by Michael Zimmerman, who has a Ph.D. in ecology. Zimmerman founded the Clergy Letter Project, a project designed to get the faithful to accept evolution by urging pastors to write letters asserting that evolution is compatible with church doctrine.  (I’m not sure how successful this has been, since there are no data about conversions. And formal church doctrine doesn’t always dictate scientific belief: although the Catholic Church formally accepts a form of theistic evolution in which human souls were created by God, 27% of American Catholics still think that modern species were created de novo by God and have remained unchanged ever since.  Statistics for mainline, non-evangelical Protestants are virtually identical.)

During “Evolution Weekend,” the faithful are supposed to discuss evolution and clasp Darwin to their bosom. That’s a good idea in principle, but Zimmerman tarnishes it by making false claims about faith and gratuitously dissing us nasty atheists.  Here, for example, is a statement from the 2012 Evolution Weekend page:

Evolution Weekend is an opportunity for serious discussion and reflection on the relationship between religion and science. An ongoing goal has been to elevate the quality of the discussion on this critical topic, and to show that religion and science are not adversaries. Rather, they look at the natural world from quite different perspectives and ask, and answer, different questions.

Religious people from many diverse faith traditions and locations around the world understand that evolution is quite simply sound science; and for them, it does not in any way threaten, demean, or diminish their faith in God. In fact, for many, the wonders of science often enhance and deepen their awe and gratitude towards God.

This is a paradigm of accommodationism, and of course a theological statement as well.  Zimmer neglects, as he must, the palpable fact that religion and science are adversaries, both in their methodology and their conclusions.  Only 16% of Americans, for example, accept evolution the way we scientists see it: as a blind, materialistic process without any divinely-imposed goal or purpose. As I’ve stressed elebenty gazillion times before, the American rejection of evolution stems almost entirely from America’s religiosity. Few creationists are secularists.

And, of course, the wonders of science must enhance and deepen one’s awe and gratitude towards God if you start out a believer, for what choice do you have? When evolution makes hash of your beliefs, you either dump them or confect rationalizations of how God of course would have used evolution as his means of creation.  Every scientific advance must redound to God’s glory, even those, like evolution, that are absolutely at odds with both scripture and people’s beliefs.

Finally, I love Zimmerman’s ludicrous statement that both science and faith “look at the natural world from quite different perspectives and ask, and answer, different questions.”  The first part is correct—the perspectives are not only different, and at odds—but the second part is garbage.  Religion asks questions like “What is the nature of God?” and “What is his plan for our lives?”, but they never answer them. Such answers are impossible for three reasons: God doesn’t exist, there’s no way to find out the answer to those questions except for the unreliable method of revelation, and those revelations have given different answers to different faiths (and to different people within a faith).  Religion doesn’t answer any questions.  If Zimmerman thinks otherwise, let him come over here and tell us what questions it’s answered.

But I digress.  Zimmerman is touting this year’s Evolution Weekend with a piece at PuffHo (where else?): “Evolution weekend: protecting both religion and science.”  Already from the title you know it’s dire: why does religion have to be protected? Here’s Zimmerman’s agenda for Evolution Weekend:

1. To protect mainstream religion from those who are attempting to define religious belief so narrowly that millions of deeply pious individuals are excluded;
2. To demonstrate that religion and science need not be at odds with each other and to show that a vast majority of religious individuals have both understanding of and respect for the principles of modern science; and
3. To create an opportunity for people to think critically and articulate carefully about these important topics. In short, they are looking to elevate the quality of the debate by pushing aside the veil of ignorance that so many purposefully have used to confuse the issue.

What, exactly, is “mainstream religion”?  Catholicism? Evanglical Protestantism? “Mainline Protestanism”? It doesn’t matter: a substantial percentage of adherents to all of those faiths reject evolution on religious grounds.  Goal number 1 is, of course, a call to protect religion from those shrill and nasty atheists who question all religious belief, no matter how “liberal.”

Point number 2 is correct: religion and science need not be at odds with each other, but only if your religion is not theistic.  That leaves deism as the one compatible form of faith.  Most religions, of course, aren’t deistic, and so are inherently at odds with science.

I also doubt Zimmerman’s claim that “a vast majority of religious individuals have both understanding of and respect for the principles of modern science”: where did he get those data?  They’re certainly not true for evolution: the vast majority of all Americans (and an even higher proportion of the faithful) either reject evolution or think that God guided the process of evolution. Religious Americans may aver that they respect science, but they certainly don’t understand it: only 59% of American adults know that dinosaurs and humans weren’t contemporaries, and only 53% of us know how long it takes for the Earth to go around the Sun (!!!).

And, as we’ve seen before from the work of Michael Sherkat, scientific illiteracy is positively correlated with religion: believers show significantly less understanding of science than do nonbelievers, and this is independent of gender, race, education, and where one lives.  (Those tests of literacy, by the way, excluded questions about evolution.)

So Zimmerman is dissimulating for Jesus.  And although he decries the fundamentalists for failing to embrace evolution, he attacks the atheists even more:

Some of the attacks on participants in Evolution Weekend 2012 will also undoubtedly come from “new atheists” who like to lump all religious individuals in with fanatical fundamentalists. In their eyes, anyone who expresses religious sentiments to even the slightest degree is no different from a Biblical literalist. These new atheists will attack the clergy who are participating in Evolution Weekend even though those very same clergy should be their biggest allies when it comes to combating the assault on science taking place in our public schools. But these new atheists can’t see past their own biases and recognize that only a combined effort will protect science.

Oh dear, oh dear, oh dear.  Most New Atheists do not lump all religious individuals in with fanatical fundamentalists: that’s just a lie on Zimmerman’s part. How many of us think that a Quaker is the same thing as an Islamic radical, or a Unitarian Universalist the same thing as a Catholic bishop who claims that condoms don’t prevent AIDS?  We don’t lump all religions together in terms of the harm they cause society. Some are worse than others.  But we do lump them together in one respect: they all believe in a celestial father for which there is no evidence.

And I’m certainly not attacking the clergy who preach Darwinism from their pulpits. More power to them.  I have little faith that they’ll achieve much (I still think that Richard Dawkins has brought far more of the faithful to evolution than any preacher), but they’re welcome to try; and if I had been invited to a church to talk about evolution, I would.  I just wouldn’t tell anyone that religion and science are friends, or compatible.

The whole disingenuous tenor of enterprises like Evolution Weekend is summed up in a statement that Zimmerman makes near the end of his piece:

The clergy members participating in Evolution Weekend and the thousands upon thousands who have signed one of The Clergy Letters supporting the teaching of evolutionary theory in public school science classes demonstrate conclusively that the entire evolution/creation dispute is not a real debate. Rather it is a contrived controversy being promoted by those advocating a single religious world view.

“Not a real debate”?  Give me a break!  It is a real debate, and one that has serious consequences for people’s worldviews. It matters to people whether there was a real Adam and Eve, or whether that’s just a fiction. It matters to people whether evolution is a blind, materialistic, and purposeless process (and, by the way, does Zimmerman advocate pastors preaching that scientifically correct view from their pulpits?), or whether God steered it toward the production of Homo sapiens. It is not “a contrived controversy”—words meant to imply that a few people cooked it up in a smoke-filled room.  It is a debate about reason and evidence, and one of vital importance to our society. And it is a debate that passionately engages many Americans.

It is this kind of stuff—this pervasive accommodationism, this disingenuous pretense that science and faith are friends, this idea that the science-religion debates are merely “contrivances”—that takes the luster off of Darwin Weekend.  By all means tell the faithful that evolution is true, but let’s not pretend that that was God’s way of creating, or that humans are a special, God-grown branch on the tree of life.  The 40% of Americans who reject evolution outright, and the 38% who think that evolution occurred but was guided by God, neither understand nor respect science, and are not my allies. My allies are those who teach evolution as it is understood by scientists.

It baffles me when I’m asked to make common cause with those who think that the “goal” of evolution was our own species, and that God inserted a soul in our ancestry somewhere along the line from Australopithecus to H. sapiens.  Forget it.

Friday squee

February 10, 2012 • 2:42 pm

Why the deuce not? Here’s a wolf cub playing with a grizzly bear cub at the Woodland Zoo in Seattle.  The pair remain fast friends after several years. As the YouTube notes say,

Lil’ Bear and Tala playing in the Gift Shop of the Woodland Zoo. Note: In the middle of the clip there are pictures of these guys as they are 6 years later. Also note that in the clip I keep referring to the bear as a “boy”, it’s actually a girl.

The blind reviewing the bland

February 10, 2012 • 11:47 am

Yes, it’s the inimitable Terry Eagleton, erstwhile critic of The God Delusion, who now fixes his sights on the milder “religious atheist” Alain “I can haz cathedral” de Botton. Eagleton, for whom I have very little use, does have his uses, as in his scathing review of de Botton’s book Religion for Atheists in the January 12 Guardian.  I haven’t read that book, but Eagleton suggests that it’s more than just a guide for how atheists can appropriate the trappings of religion.  It also seems to be a manual of “belief in belief.” As Eagleton says,

There is something deeply disingenuous about this whole tradition. “I don’t believe myself, but it is politically prudent that you should” is the slogan of thinkers supposedly devoted to the integrity of the intellect. . . .

God may be dead, but Alain de Botton‘s Religion for Atheists is a sign that the tradition from Voltaire to Arnold lives on. The book assumes that religious beliefs are a lot of nonsense, but that they remain indispensible to civilised existence. One wonders how this impeccably liberal author would react to being told that free speech and civil rights were all bunkum, but that they had their social uses and so shouldn’t be knocked. Perhaps he might have the faintest sense of being patronised.

LOL!  Well said, even if it is by Eagleton.  Smart believers do know when they’re being patronized. The mystery is why there are smart believers in the first place. Eagleton continues the evisceration:

. . . What the book does, in short, is hijack other people’s beliefs, empty them of content and redeploy them in the name of moral order, social consensus and aesthetic pleasure. It is an astonishingly impudent enterprise. It is also strikingly unoriginal. Liberal-capitalist societies, being by their nature divided, contentious places, are forever in search of a judicious dose of communitarianism to pin themselves together, and a secularised religion has long been one bogus solution on offer. The late Christopher Hitchens, who some people think is now discovering that his broadside God Is Not Great was slightly off the mark, would have scorned any such project. He did not consider that religion was a convenient fiction. He thought it was disgusting. Now there’s something believers can get their teeth into …

Umm. . . the gratuitious slap at Hitchens, of course, implies that Hitch got it wrong and is now roasting in hell (alternatively, with God’s grace he might be imbibing with the angels). I wonder if Eagleton, who appears to be a Christian but is loath to admit it explicitly, shares that view.

But there is a parallel here between Eagleton and me: both of us dislike “believers in belief” for their hypocrisy and lack of intellectual honesty.  On those counts give me an honest fundamentalist over an accommodationist, just as Eagleton would prefer an honest atheist like Hitchens to a milquetoast accommodationist like de Botton.

Why do zebras have stripes?

February 10, 2012 • 9:38 am

Well, I can’t give a definitive answer to that question, but I can start by telling you that zebras are not white with black stripes, but black with white stripes. The ground color in embryos is black, and the white stripes appear later in development in areas where the deposition of melanin pigment is inhibited.

But of course you’re wondering why they have stripes at all.  Various hypotheses have been suggested, the most famous being camouflage, confusion of predators, or even thermoregulation.  None of these have been experimentally supported, for it’s hard to test them. (The camouflage story, though, doesn’t hold up since it depends on zebras hiding in tall grass, but they live on the savanna where tall grass is almost nonexistent.)

There is, however, a new hypothesis that has garnered some experimental support: it’s presented and tested in a new paper in the Journal of Experimental Biology by Ádám Egri et al. This is a rather long and complicated paper, and perhaps I’d best refer you to the BBC report of the findings, which contains a quote from our own Matthew Cobb.

In short, experiments on Hungarian horse farms using model horses and other targets for flies suggest that the striped pattern reduces the kind of polarized light that attracts blood-sucking tabanid flies (“horseflies”). Those flies are attracted to horizontally polarized light, presumably because that’s a sign of water, and water is where female tabanids lay their eggs.  Model horses and pans of fly-attracting oil painted with a dark color are very attractive to flies; white models less so.  Surprisingly, striped models attracted the fewest flies, and the stripe width that was the most deterrent was that actually present on the heads and legs of all three existing species of zebras.

The authors theorize that the adaptive significance of the stripes is to deter tabanids in Africa, because fly bites can reduce grazing, and hence survival and fertility.

It’s a reasonable theory, but has a few problems.  First, there’s some special pleading about the width of stripes: as I said, the most deterrent widths are those found on the zebra’s heads and legs, not on their backs, where the stripes are wider (see below). To explain this, the authors argue that the heads are important for survival because they contain vital sensory organs, and the legs are critical because they “are indispensable to escape from predators.” (The authors also claim the blood vessels are closest to the skin in these places.) But that doesn’t explain why the stripes aren’t the same fly-deterring width all over the body.

Here’s a Grant’s Zebra  (Equus quagga boehmii, a subspecies of the Plains zebra).  Note that the stripes are narrowest on the head and legs:

Matthew Cobb, quoted in the BBC piece, raises another problem:

Prof Matthew Cobb, an evolutionary biologist from the University of Manchester pointed out that the experiment was “rigorous and fascinating” but did not exclude the other hypotheses about the origin of zebras’ stripes.

“Above all, for this explanation to be true, the authors would have to show that tabanid fly bites are a major selection pressure on zebras, but not on horses and donkeys found elsewhere in the world… none of which are stripy,” he told BBC Nature.

Indeed!  To add to that, there’s another fly that could be a serious pest on zebras in Africa: the tsetse fly, although the authors claim that tsetses don’t bite zebras as often as they do other mammals. But zebras are susceptible to the trypanosome parasite that causes human sleeping sickness (and makes horses chronically ill), and the authors didn’t test whether stripes deterred tsetse flies. (The experiments were, after all, done in Hungary where the tsetse doesn’t live.)

I find the authors’ hypothesis intriguing and the data somewhat convincing, but there could be other reasons for stripes that we just don’t understand.  And, as Matthew noted above, we also need to explain why most species of equids lost their stripes, because it’s pretty clear that the ancestral equid was striped. (Darwin noted this in The Origin when he pointed to the existence of occasional stripes in domesticated horses as evidence for the occasional re-expression of an ancestral trait). Do unstriped equids not encounter horseflies? Or was a stripey pattern too conspicuous to predators?

And someone needs to investigate this problem in felids.

____________

Egri, A. M. B., G/ Kriska, R. Farkas, M. Gyurkovszky, S. Åkesson and, and G. Horváth. 2012. Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes. J. Experimental Biol. 215:736-745.