Regulatory evolution of the Hox1 gene

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I’ve been getting swamped with links to this hot article, “Evolution reversed in mice,” including one from my brother (hi, Mike!). It really is excellent and provocative and interesting work from Tvrdik and Capecchi, but the news slant is simply weird—they didn’t take “a mouse back in time,” nor did they “reverse evolution.” They restored the regulatory state of one of the Hox genes to a condition like that found half a billion years ago, and got a viable mouse; it gives us information about the specializations that occurred in these genes after their duplication early in chordate history. I am rather amused at the photos the news stories are all running of a mutant mouse, as if it has become a primeval creature. It’s two similar genes out of a few tens of thousands, operating in a modern mammal! The ancestral state the authors are studying would have been present in a fish in the Cambrian.

I can see where what they’ve actually accomplished is difficult to explain to a readership that doesn’t even know what the Hox genes are. I’ve written an overview of Hox genes previously, so if you want to bone up real quick, go ahead; otherwise, though, I’ll summarize the basics and tell you what the experiment really did.

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Hooterology?

We seem to be talking about breasts a lot this week, don’t we? Abel Pharmboy raises a provocative ethical question: is it crass or is it reasonable for breast cancer researchers to ask Hooters to promote breast cancer awareness? I’m of the opinion that we ought to get every penny we can from them, but stop short of giving any hint that we actually endorse their business…although I’d wonder if even asking them for their assistance is granting them respectability, or if acknowledging the assistance of Hooters would turn a serious event into a joke.

It’s probably best to post your answers to Terra Sigillata. I’d really be interested to see Twisty‘s opinion!

(Just a wild thought…I wonder how much money doctors could get for naming rights. Offer to change the name of the disease to Hooter’s™ cancer. I know, that’s even more tasteless than getting them to sponsor a meeting.)

The ubiquitous Francis Collins

Collins has another published interview in Salon. It’s sad, actually—in every new interview, he says pretty much the same thing, but he digs himself in a little deeper. I ordered his book the other day, and now I’m beginning to regret it; it’s beginning to sound like trite Christian apologetics with no depth, no self-reflection, no insight…just compound anecdotes intended to rationalize a conclusion he has arrived at with no evidence. It’s distressingly anti-scientific.

For instance, we get an expansion of his hiking anecdote:

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I must be some kind of purist

Lots of sources are telling me about Pat Robertson’s sudden acceptance of the fact of global warming. I’m sorry, but it’s no cause for rejoicing. He accepts it for the wrong reasons.

This week the heat index, the perceived temperature based on both air temperatures and humidity, reached 115 Fahrenheit in some regions of the U.S. East Coast. The 76-year-old Robertson told viewers that was “the most convincing evidence I’ve seen on global warming in a long time.”

If there’s one broad, overall message I wish everyone would get from this blog and from my teaching, it’s that science isn’t about getting the right answers—it’s about how you arrive at your answers, by verifiable, testable, repeatable methods and logic and good evidence. Deciding that global warming occurs because you’re having a hot, sticky, uncomfortable summer: bad and unscientific. Deciding that global warming occurs because the climate research community has evaluated multiple lines of evidence and documented an anomalous pattern: smart.

I’m sorry, Jake, but while getting the religious right on the side of conservation is a good thing, doing so on the say-so of an incompetent authority like Pat Robertson who uses an anecdote about the weather to justify it is a bad thing. What are we going to do if Colorado has a blizzard in January, and James Dobson uses that to argue that an Ice Age is on the way? Or if Jerry Falwell has a bout of incontinence, so he prophesies great floods?

Evolution of median fins

Often, as I’ve looked at my embryonic zebrafish, I’ve noticed their prominent median fins. You can see them in this image, although it really doesn’t do them justice—they’re thin, membranous folds that make the tail paddle-shaped.

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These midline fins are everywhere in fish—lampreys have them, sharks have them, teleosts have them, and we’ve got traces of them in the fossil record. Midline fins are more common and more primitive, yet usually its the paired fins, the pelvic and pectoral fins, that get all the attention, because they are cousins to our paired limbs…and of course, we completely lack any midline fins. A story is beginning to emerge, though, that shows that midline fin development and evolution is a wonderful example of a general principle: modularity and the reuse of hierarchies of genes.

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Voices of science

If you’re at work, I hope you have headphones; if you don’t, check in once you get home. Here are a couple of audio recordings of good science.