Fish courtship and sex

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I’ve been a bit sex-obsessed lately. No, no, not that way—it’s all innocent, and the objects of my obsessions are all fish.

A little background explanation: one of my current research projects is on the genetics of behavior. This is a difficult area, because behavior is incredibly complex with multiple levels of causation, and one has to be very careful when trying to tease apart all the tangled factors that contribute to it. It takes numbers and lots of controls to sort out the various contributors to a behavior.

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Morphological embryology of a sea spider

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Tanystylum bealensis male, ventral view, showing eggs and instar 1 (protonymphon) on
ovigerous legs. in. 1, instar 1 (protonymphon); pa, palp; pr, proboscis; 1, first walking leg; 2, second
walking leg; 3, third walking leg; 4, fourth walking leg.

Surely, you haven’t had enough information about pycnogonids yet, have you? Here’s another species, Tanystylum bealensis, collected off the British Columbian coast. That’s a ventral view of the male, and those bunches of grapes everywhere are eggs and babies—males do the childcare in this group. These animals also live in relatively shallow water, in the lower intertidal zone, so it was possible to collect thousands of them and develop a complete staging series. Below the fold I’ve put some illustrations of the larvae, which are even cuter.

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Yah boo, Jonathan Wells!

That Moonie creationist with a degree in developmental biology, Jonathan Wells, floated an actual hypothesis a while back: he postulated that the centrioles were little turbines that generated a force with their rotation. I never saw it as much of a support for Intelligent Design; it was an idea about how centrioles function that did not rule out that they arose by evolutionary mechanisms. Wells seemed to think it was significant because he was inspired by an analogy with a human artifact, but la de da…I don’t think benzene rings are actually made of snakes, despite Kekule’s inspiration.

Anyway, now Ian Musgrave hammers another stake through that idea’s heart: Wells’ hypothesis is falsified.

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.)