Evolving snake fangs

Blogging on Peer-Reviewed Research
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Ontogenetic allometry in the fang in the front-fanged Causus rhombeatus (Viperidae) displaces the fang along the upper jaw. Scale bars, 1 mm. We note the change in relative size of the upper jaw subregions: i, anterior; ii, fang; iii, posterior. d.a.o., days after oviposition.

I keep saying this to everyone: if you want to understand the origin of novel morphological features in multicellular organisms, you have to look at their development. “Everything is the way it is because of how it got that way,” as D’Arcy Thompson said, so comprehending the ontogeny of form is absolutely critical to understanding what processes were sculpted by evolution. Now here’s a lovely piece of work that uses snake embryology to come to some interesting conclusions about how venomous fangs evolved.

Basal snakes, animals like boas, lack venom and specialized fangs altogether; they have relatively simple rows of small sharp teeth. Elapid snakes, like cobras and mambas and coral snakes, are at the other extreme, with prominent fangs at the front of their jaws that act like injection needles to deliver poisons. Then there are the Viperidae, rattlesnakes and pit vipers and copperheads, that also have front fangs, but phylogenetically belong to a distinct lineage from the elapids. And finally there are other snakes like the grass snake that have enlarged fangs at the back of their jaws. It’s a bit confusing: did all of these lineages independently evolve fangs and venom glands, or are there common underpinnings to all of these arrangements?

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Uh-oh…a pro-life poll

Here’s one way to foil a pharynguloid poll invasion: limit your poll answers to those that aren’t even wrong. Try to answer the question of”When does life begin?” — your only choices are at birth, at conception, at some stage, with a god (?), and the ever-useful “I don’t know”. Conception is winning right now, when everyone knows the correct answer is approximately 4 billion years ago. There is no dead stage in the cycle of life!

The alternative answer is “after the kids all move out”, but that option isn’t listed, either.

Karl Giberson strikes back!

Perhaps you remember Karl — I ripped into an interview he did a while back. Well, “ripped into” is probably the wrong phrase — I pointed out several things I thought were quite good, and then tore up his sectarian defense of Christianity, his blind obeisance before the Christian bible, and his mangling of what other scientists have said about religion. It must have rankled — he now gripes that “Myers doesn’t seem to like me” and has slapped together a nice bit of hackwork that is the lead story on Salon. And clumsy hatchet job it is.

Here’s his opening:

PZ Myers is a true believer, a science crusader with the singled-minded enthusiasm of a televangelist. A biologist at the University of Minnesota at Morris and a columnist for Seed magazine, Myers has earned notoriety with his blog, Pharyngula, in which he reports on new developments in biology and indiscriminately excoriates those he views as hostile to science, a pantheon of straw men and women that includes theologians, journalists and churchgoers. He is Richard Dawkins without the fame or felicitous prose style.

Then he recounts the tale of the “Great Desecration”, but without any of the context, not bothering to mention the hideous history of the Catholic response to rumors of desecration, and not even mentioning Bill Donohue’s bullying tactics. Oh, and then he compares me to Jonathan Edwards, misrepresents his own interview — he only “suggested that science doesn’t know everything,” which “got [him] condemned to whatever hell Myers believes in” — and claims that atheists like me, Dawkins, Atkins, and Dennett are just practicing a new religion. Over and over again. He goes on at length with this strange claim that we are pushing science as a replacement for religion.

But let’s assume for the moment that this is possible — that science can be canonized, moralized, transcendentalized and politicized into a replacement religion, with followers, codes of conduct, celebrated texts and sacred blogs, houses of worship, “saints” of some sort and inquisitors of another sort. And let’s suppose that it’s possible for this new religion to move out of the ivory towers of academia, where it lives now, to take its place alongside the other “world” religions, attracting hundreds of millions of adherents drawn from the main streets of the world and all walks of life. What would this new religion be like once it became institutionalized? After all, if religion fills a genuine human need, something has to fill the hole created by its passing — something that appeals to billions of people.

He babbles on quite a bit about this bizarre fantasy that we’re trying to replicate the silly superstitions and rituals of his idea of religion. Sacred blogs? Saints? This is just foolishness of his own invention. Right there in the critical post I wrote, I said plainly, “Gould and Dawkins do not claim that evolution as a religion, or that it should be treated as one, and neither do I; that would be ridiculous, since if I were equating the two, that would mean I think people ought to grow out of their absurd faith in evolution.” In the desecration post, I plainly said that nothing should be sacred. Giberson read those, apparently, and then decided that I really meant the opposite.

It’s funny how he provides these botched descriptions of what I said, but doesn’t bother to actually link to it, where it’s rather obvious that his version is misleading and dishonest.

Oh, and I’m not one of the saints. Here’s my role.

And we have inquisitors like Myers to ferret out heretics and martyr them on his Web site when they appear.

Man, my criticism of his ideas must have really burned, that he would now compare me to inquisitors and his own state to martyrdom. Hint to Karl: Catholic inquisitors tied people to stakes and literally set them on fire. Writing in dissent about someone’s ideas does not really compare very well. I might add that historically, Christians murdered Jews by the thousands for imaginary desecrations; I tossed an unpalatable scrap of bad bread in a garbage can. Any comparisons he wants to make will not flatter religion.

In order for many of us to truly feel at home in the universe so grandly described by science, that science needs to coexist as peacefully as possible with the creation stories of our religious traditions. I share with Myers, Dawkins and Weinberg the conviction that we are the product of cosmic and biological evolution, that Einstein and Darwin got it right. But I want to believe that, through the eyes of my faith, this is how God created the world and that God cares about that world. Does this belief, shared by so many of our species, make me dangerous?

No, Karl, it makes you foolish. The eyes of your faith are delusions fostered by tradition and dogma, there is no evidence for your god or that he created anything, and there sure as heck isn’t any evidence that your imaginary friend cares about us.

It also makes Salon look foolish, that they would put an article written by someone with a patent grudge front and center.

Looking for a host, and it’s Molly Time

No, not that kind of host. Our scheduled host for the Tangled Bank had to back out due to time constraints. If anyone wants to volunteer to host it next Wednesday, let me know and I’ll forward the entries to you.

Also, who should get a Molly award for the month of July? Mention your choice(s) and reasoning in the comments here. I’ll tally ’em up at the end of this weekend.


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Tangled Bank hosting is taken care of: the first volunteer was PalMD of the denialism blog. Start mailing those links in!

Tyrannosaur morsels

Blogging on Peer-Reviewed Research
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This story is in the news again, so I’ve reposted my description of the paper from 3½ years ago. This is an account of the discovery of soft organic tissue within a fossilized dinosaur bone; the thought at the time was that this could actually be preserved scraps of Tyrannosaurus flesh. There is now a good alternative explanation: this is an example of bacterial contamination producing a biofilm that has the appearance of animal connective tissue.

Read GrrlScientist’s explanation and Greg Laden’s commentary and Tara Smith’s summary of the recent PLoS paper that tests the idea that it is a biofilm.


Look! A scrap of soft tissue extracted from dinosaur bone:

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Demineralized fragments of endosteally derived tissues lining the marrow cavity of the T. rex femur. The demineralized fragment is flexible and resilient and, when stretched (arrow), returns to its original shape.

It has been reported in Science this week that well-preserved soft tissues have been found deep within the bones of a T. rex, and also within some hadrosaur fossils. This is amazing stuff; fine structure has been known to be preserved to this level of detail before, but these specimens also show signs of retaining at least some of their organic composition. What the authors have done is to carefully dissolve away the mineral matrix of the bone, exposing delicate and still flexible scraps of tissue inside.

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The Confraternity of Catholic Clergy doesn’t like me

An organization of the Catholic leadership has now condemned my actions. This is sad news: it’s clear that at least this tier of the Catholic hierarchy is as deranged as the wackaloons flooding my mailbox.

We find the actions of University of Minnesota (Morris) Professor Paul Myers reprehensible, inexcusable, and unconstitutional. His flagrant display of irreverence by profaning a consecrated Host from a Catholic church goes beyond the limit of academic freedom and free speech.

Hmmm. Who is the Confraternity of Catholic Clergy to decide the limits of freedom? Flagrant irreverence towards a cracker ought to be fair game, I should think…and that’s all this action was: irreverence. You cannot demand that all members of a pluralist society be reverent towards any random humdrum article that a guy in a dress declares holy.

The same Bill of Rights which protect freedom of speech also protect freedom of religion. The Founding Fathers did not envision a freedom FROM religion, rather a freedom OF religion. In other words, our nation’s constitution protects the rights of ALL religions, not one and not just a few.

Man, that is a tired old argument — usually you see that fine-grained parsing of the words of the bill of rights from right-wing sources, trying to distort the meaning. Do they really think a bunch of high-minded Enlightenment dudes dedicated to the principle of liberty were thinking, “We need a clause here that could be used to compel people to be a member of a church—we’ll just give them the freedom to choose which church they’ll be forced to join”? That’s insane. I am free of religion. I am free to make that choice, just as everyone is free to choose to be Catholic.

And my personal choice not to believe in the silliness of religion is not an infringement on the rights of any religion.

The freedom of religion means that no one has the right to attack, malign or grossly offend a faith tradition they personally do not have membership or ascribe allegiance.

This is the funniest statement in the whole declaration.

Freedom of speech means I do have the right to malign and make fun of any religion I want. I can’t interfere with your right to practice your religion, but that hasn’t happened — all I’ve done is laugh at you.

That last clause, though…do they seriously believe that only Catholics are allowed to criticize Catholics, and that this restriction is enshrined in the constitution? That’s a fine catch, that catch-22. So only Catholics can malign the faith, but if they do, then they can be kicked out of the faith, which means they can’t criticize it anymore. That sounds like a ripe piece of theological logic to me.

The Chancellor of the University refused to reprimand or censure the teacher, who ironically is a Biology Professor. One fails to see the relevance of the desecration of a Catholic sacrament to the science of Biology. Were Myers a Professor of Theology, there would have been at least a presumption of competency to express religious opinions in a classroom. Yet, for a scientist to ridicule and show utter contempt for the most sacred and precious article of a major world religion, is inappropriate, unprofessional, unconstitutional and disingenuous.

Ummm, I don’t discuss religion in the classroom. I teach biology. My ‘desecration’ was performed at home, on my own time. There’s nothing ironic about the fact that I’m a biologist, nor did I claim my profession gave me special qualifications to see through the foolishness of faith. Go ahead, any of you can do it — you don’t need to be a theologian to see that it is just a cracker.

A biologist has no business ‘dissing’ any religion, rather, they should be busy teaching the scientific discipline they were hired to teach. Tolerating such behavior by university officials is equally repugnant as it lends credibility to the act of religious hatred. We also pray that Professor Myers contritely repent and apologize.

Wait, what? This is another attempt to shield a ridiculous religion, by declaring that members of certain professions are not allowed to criticize — that only Catholic theologians are permitted to rebuke the absurdities in their faith.

As for the idea that I’m supposed to be teaching biology 24-7…what, I can’t have a hobby? I can tell you that when I try to tell my wife late evening on Wednesday night that I can’t take out the trash because I’m too busy teaching biology, well, that excuse won’t fly very far.

I am not contrite, I will not repent, and I’m certainly not going to apologize for tossing a cracker in the garbage. All the Confraternity of Catholic Clergy will get from me is laughter.

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