This has been a bountiful week at Chez Pharyngula, and I have received generous gifts from several readers. A full accounting lies below the fold.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
This has been a bountiful week at Chez Pharyngula, and I have received generous gifts from several readers. A full accounting lies below the fold.
He went to the Walcott Quarry for his vacation. And he waved his photos under my nose.
I got this email from Alan Kazlev, one of the main fellows working on the Palaeos website (a very useful paleontological resource), which I had previously reported as going offline. Plans are afoot to bring it back, and the answer seems to be to wikify it and build it anew, with a more distributed set of contributors. How Web 2.0! I’ve included the full email below the fold if you’d like more details.
Palaeos is gone! There is a brief note about being unable to support it any longer, and then poof, it’s offline. Martin Brazeau has a comment on it’s value; you can still see fragments of this great resource in google’s cache, but even that will fade too soon.
This is troubling, and it’s one of the worrisome aspects of using the net—there’s no sense of permanence. It would be good if someone were to step forward and at least archive all of the pages, but the essential feature of the Palaeos site was that it was continually maintained and updated to reflect current information, and that’s not something that can be supported without the dedication of much time and effort by someone knowledgeable in the subject.
Next time you’re cutting up a fresh bird, try looking for the lungs. They’re about where you’d expect them to be, but they’re nestled up dorsally against the ribs and vertebrae, and they’re surprisingly small. If you think about it, the the thorax of a bird is a fairly rigid box, with that large sternal keel up front and short ribs—it’s a wonder that they are able to get enough air from those tiny organs with relatively little capability for expanding and contracting the chest.
How they do it is an amazing story. Birds have a radically effective respiratory system that works rather differently than ours, with multiple adaptations working together to improve their ability to take in oxygen. There is also a growing body of evidence that dinosaurs also shared many of these adaptations, tightening their link to birds and also making them potentially even more fierce—they were big, they were active, and their lungs were turbocharged.
Zimmer has a summary of the latest discoveries in the evolution of the baleen whales. It’s beautiful stuff, with the lineage showing their origin from toothed whales, through a phase where they had both teeth and baleen, to their current condition lacking teeth and having only baleen.
Phosphatized pre-Cambrian embryos are cool. It’s amazing that they’ve been preserved at all, and they are spectacularly gorgeous. We can learn about the evolution of development from their superficial appearance, but what we really want to do is poke around their interiors and analyze them cell by cell, something that has been hard to do without destroying them in the process. Until now.
A report in Nature (and a too short mention on a researcher’s web page) describes the application of synchrotron X-ray tomographic microscopy (SRXTM) to these fossilized embryos to resolve their internal structure. It’s a powerful tool, and it’s generating some beautiful images.
You may recall that Martin Brazeau was going to spend July doing fieldwork—well, he’s back, and is going to be telling us about his exciting month in a Canadian cow pasture, if ever you wanted to hear a first-hand account of paleontological research.
Muton has some splendid photos of fossil spiders.
Yunnanozoans and Xidazoon…there are some very pretty early Cambrian critters on display at Sinanthropus.
