Two legged goats and developmental variation

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Variation is common, and often lingers in places where it is unexpected. The drawing to the left is from West-Eberhard’s Developmental Plasticity and Evolution(amzn/b&n/abe/pwll), and illustrates six common variations in the branching pattern of the aortic arch in humans. These are differences that have no known significance to our lives, and aren’t even visible except in the hopefully rare situations in which a surgeon opens our chests.

This is the kind of phenomenon in which I’ve become increasingly interested. I work with a model system, the zebrafish, and supposedly one of the things we model systems people pursue is the ideal of a consistent organism, in which the variables are reduced to a minimum. Variation is noise that interferes with our perception of common underlying mechanisms. I’ve been thinking more and more that variation is actually a significant phenomenon that tells us something about where the real constraints in the system are. It is also, of course, the raw material for evolution.

Unfortunately, variation is also relatively difficult to study.



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I’m redundant-who needs a blogger?

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There’s a lovely article in this week’s Nature documenting a transitional stage in tetrapod evolution (you know, those forms the creationists like to say don’t exist), and a) Nature provides a publicly accessible review of the finding, and b) the primary author is already a weblogger! Perhaps there will come a day when I’m obsolete and willl just have to turn my hand to blogging about what I had for lunch.

For an extra super-duper dose of delicious comeuppance, though, take a look at this thread on the Panda’s Thumb. I wrote about Panderichthys, and a creationist (“Ghost of Paley”) comes along to mangle the phylogeny and make wild negative assertions about the validity of interpretations of fossils based on work from the Ahlberg lab…when Martin Brazeau of the Ahlberg lab and author of this new paper shows up to straighten him out.

And for my next trick, let me introduce you to Marshall McLuhan…

Brazeau MD, Ahlberg PE (2006) Tetrapod-like middle ear architecture in a Devonian fish. Nature 439:318-321.

Where are the spineless?

Hey! I’m supposed to host the Circus of the Spineless next week (I think on 29 January), and I’ve only received one submission so far! Someone must have written something somewhere about invertebrates, right? There is a set of rules for submissions, but it’s going to be simple: I’ll accept anything about any organisms outside the class Vertebrata.

I’ll spell it out. You can write about the phyla Acanthocephala, Acoelomorpha, Annelida, Arthropoda, Brachiopoda, Bryozoa, Chaetognatha, Cnidaria, Ctenophora, Cycliophora, Echinodermata, Echiura, Entoprocta, Gastrotricha, Gnathostomulida, Hemichordata, Kinorhyncha, Loricifera, Micrognathozoa, Mollusca, Myxozoa, Nematoda, Nematomorpha, Nemertea, Onychophora, Orthonectida, Phoronida, Placozoa, Platyhelminthes, Pogonophora, Porifera, Priapulida, Rhombozoa, Rotifera, Sipuncula, Symplasma, or Tardigrada, and that’s fine. You can even write about the Urochordata, the Cephalochordata, and the Myxini within the phylum Chordata. The overwhelming majority of animal species are fair game, so there is absolutely no excuse if anyone tries to send me a picture of their cat. Understand? Fish, frogs, lizards, birds, mammals, dinosaurs, and your baby pictures are right out.

I’m also going to accept multiple submissions, if you’ve been manic about documenting the breadth of biodiversity. We shall do our best to overcome the bias of the blogosphere for kitties and other furred and feathered and scaled beasties.

Although the tagline for the circus says it is a monthly celebration of “most anything else that wiggles”, I’m also going to break the shackles of metazoan chauvinism, so if you want to send in something about protists, lichens, fungi, plants, whatever, anything but things with a spinal column, I’ll accept them and put them in an honored category of their own.

Open Thread

Open Thread

I’m doing some traveling and touristy things with grrlscientist today, on top of somehow coping with the first week of classes (physiology and our freshman seminar in biological principles), and attending Drinking Liberally at the 331 Club tonight. I also have to get tickets to the Prairie Home Companion show that will be taped here at UMM on 11 February…it all adds up to me being a little scattered and distracted and otherwise occupied for much of today. You all are just going to have to fend for yourselves for a bit.

Here is a short list of things I should write about, but won’t get to today.

I do have some Science!!! to write about, but first I have to clear up some time in an overloaded schedule.

Why stay in NY when you can visit Morris?

You wouldn’t know it to see it, but we aim to make Morris, Minnesota the Mecca of science blogging. How else to explain how we could draw Grrlscientist away from that boring dump of a town, New York, to visit our lovely prairie village for a week? It’s true: a whole two of us ScienceBlogs people are chattering away from this lonely outpost in the rural wilderness.

Any other science bloggers who want to stop on by, feel free. We’ve got a roomy house with a zippy wireless connection, and who needs anything more? Jay Manifold has been here, Radagast once drove by within a few hundred miles, and now we’re hosting Living the Scientific Life…I think that’s enough to qualify as a Mecca, right?

Anyway, we’re planning to cruise into Minneapolis tomorrow, see the Big City, and check out Drinking Liberally at the 331 Club around about 6—somebody alert the Power Liberal, Tild, and the Wege…we got some tough-talkin’, crazed scientists planning to crash their party.

We’re also hosting an event of our own here at Chez Myers on Friday, with the first
SOFA (Something On Friday Afternoon, a Morris tradition) of the semester at our place. If anyone wants to crash our party, just come on by.

Discovery Institute uses immense clout, kills Intelligent Design course

That school in California that tried to teach a creationist “philosophy” course was chewed out by Casey Luskin of the Discovery Institute. Luskin’s statement consisted of the usual folderol, but the outright fraud of several statements leapt out at me.

My name is Casey Luskin and I am an attorney representing the Discovery Institute. The Discovery Institute is a think tank based out of Seattle, Washington that represents a large number of scientists who do scientific research into intelligent design.

A “large number of scientists”? How many?

Scientists “who do scientific research into intelligent design”? Name them. Tell us exactly where they are doing their research and what specific questions they are trying to answer.

But if you do not cancel this course, and if you let this lawsuit go forward, you are going to lose and there will be a dangerous legal precedent set which could threaten the teaching of intelligent design on the national level. Such a decision would also threaten the scientific research of many scientists who support intelligent design.

See questions above. What scientists? What research?

I’m really fed up with this phony baloney the DI keeps pushing. There are darned few scientists backing Intelligent Design, and those few don’t do any research, nor can they tell anyone else what research could be done.

Because of the young earth creationist history of this course, this course is not legally defensible and it should be cancelled. Thank you.

Casey Luskin got his wish. The course has been cancelled. Not without a final irony, though:

Sharon Lemburg, a social studies teacher and soccer coach who was teaching “Philosophy of Design,” defended the course in a letter to the weekly Mountain Enterprise.

“I believe this is the class that the Lord wanted me to teach,” she wrote.