Finding a big dead thing would be the highlight of anyone’s day

Usually, on my morning walk, I keep my eyes open for any squid that might have washed up on the sidewalks of Morris. Now I learn that the squid wash up on the beaches of Tasmania. I suppose a place nearer an ocean is a more likely spot. (By the way, TONMO is the site to check for more news on the beached squid carcass—and they think it is unlikely that it’s actually a giant squid.)

Maybe I should start scanning for dead baby mammoths, instead.

Common elements of eumetazoan gene organization in an anemone

We now have a draft of the sea anemone genome, and it is revealing tantalizing details of metazoan evolution. The subject is the starlet anemone, Nematostella vectensis, a beautiful little animal that is also an up-and-coming star of developmental biology research.

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(click for larger image)

Nematostella development. a. unfertilized egg (~200 micron diameter) with sperm head; b. early cleavage stage; c. blastula; d. gastrula; e. planula; f. juvenile polyp; g. adult stained with DAPI to show nematocysts with a zoom in on the tentacle in the inset; h, i. confocal images of a tentacle bud stage and a gastrula respectively showing nuclei (red) and actin (green); j. a gastrula showing snail mRNA(purple) in the endoderm and forkhead mRNA (red) in the pharynx and endoderm; k. a gastrula showing Anthox8 mRNA expression; l. an adult Nematostella.

A most important reason for this work is that the anemone Nematostella is a distant relative of many of the animals that have already been sequenced, and so provides an essential perspective on the evolutionary changes that we observe in those other organisms. Comparison of its genome with that of other metazoans is helping us decipher the likely genetic organization of the last common ancestor of all animals.

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Segmentation genes evolved undesigned

Jason Rosenhouse has dug into the details of the evo-devo chapter of Behe’s The Edge of Evolution and found some clear examples of dishonest quote-mining (so what else is new, you may be thinking—it’s what creationists do). I’ve warned you all before that when you see an ellipsis in a creationist quote, you ought to just assume that there’s been something cut out that completely contradicts the point the creationist is making; Rosenhouse finds that Behe gets around that little red-flag problem by simply leaving out the ellipses.

I just want to expand a little bit on one point Behe mangles and that Jason quotes. It turns out I actually give a lecture in my developmental biology courses on this very issue, the mathematical modeling antecedents to insect segmentation, so it’s simply weird to see Behe twisting a subject around that is so well understood in the evo-devo community, and that was actually well explained in Sean Carroll’s Endless Forms Most Beautiful.

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