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.


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.

[Read more…]

In which I (partially) agree with Paul Nelson

It feels good to see the IDist crackpots beaten back a little bit in their bid to control the Kansas school board, and I think it is necessary to keep up the pressure and prevent them from getting a better grip on public school education. However, Paul Nelson actually has a point with his little parable. It’s not the point he thinks he’s making, but it’s important to keep in mind anyway, and I’m going to dash some cold water on any sense of triumphalism on the pro-science side.

[Read more…]

Taking my name in vain

This is a new low: if you read this post by a fellow atheist, you’ll see a critical comment by “PZ Myers.” Thing is, it wasn’t me.

I guess we’ve got some cowardly kook wandering about, leaving comments with my name stuck on them, in an attempt to simultaneously annoy others and discredit me. Nice. If anyone else is getting what seem to be out-of-character comments from me, let me know…it would also be good if you had a way to let me know the IP address of the imposter.

In a related situation, read this story about a fake ‘atheist’ blog purporting to label the good, the bad, and the ugly atheists (no, I’m not mentioned in any of the categories)—it reeks of astroturf.

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.