Cosmology is almost as interesting as developmental biology, and now you can read a short summary of the origins of the universe at Daily Kos.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
Cosmology is almost as interesting as developmental biology, and now you can read a short summary of the origins of the universe at Daily Kos.
This new strange question is sweeping the scienceblogs: “what kind of scientist is Batman?”
The answer is obvious.
While I was out playing all day yesterday, a new Tangled Bank appeared at Centrerion. I’m so late in my announcement that you’ve probably all read it already, but if you haven’t, there’s much science writing to occupy you for a while.
PvM at the Panda’s Thumb has already written a bit about this issue in the article “Human Gland Probably Evolved From Gills”, but I’m not going to let the fact that I’m late to the party stop me from having fun with it. This is just such a darned pretty story that reveals how deeply vertebrate similarities run, using multiple lines of evidence.
Cephalopods can inflict a nasty bite. On their underside, at the conjunction of their arms, they have a structure called the beak which does look rather like a bird’s beak, and which can close with enough force to crush shellfish. Many also dribble toxins into the wound that can cause pain, tissue necrosis, and paralysis. They aren’t the best animals to play with.
If you think about it, though, cephalopods don’t have a rigid internal skeleton. How do they get the leverage to move a pair of sharp-edged beaks relative to one another, and what the heck are they doing with a hard beak anyway? There’s a whole paper on the anatomy of just the buccal mass, the complex of beak, muscle, connective tissue, and ganglia that powers the cephalopod bite.
The very first edition of Mendel’s Garden, a genetics carnival, is now up at The force that through….
While I’m at it, let me remind everyone that a new Tangled Bank will be appearing at Centrerion on Wednesday—now is the time to send entries to me or host@tangledbank.net.
My kids like these energy drinks that are so popular nowadays—so it’s useful to learn what is in Red Bull. It looks like I won’t have to slap that can out of their hands next time I catch the whippersnappers drinking it (although I may have to give them a lecture about being thrifty—we fogies have to have something to complain about.)
I’ve been listening to Bethell vs. Mooney on Science Friday, and I’ve come to one conclusion: I really need to slap Ira Flatow. Repeatedly. And maybe kick him a few times, too.
He was playing right into Bethell’s hands. Bethell was rambling and vague, and he went on and on, and Flatow fed into it. Mooney had to interrupt several times and demand a chance to rebut (and good for him—he was on the attack, as he needed to be), and at least once Flatow stopped Mooney for a commercial and then asked Bethell to follow up afterwards.
Worse, Flatow wouldn’t allow any depth. They’d start getting into HIV and Bethell’s denial, and just as Mooney was getting into it, he’d say, “Now we need to talk about global warming!” Come on, FOCUS. The strengths of science come into play when we have a chance to dig deep and actually grapple with the issues; Bethell is a superficial flibbertigibbet who knows nothing, and this show gave him a forum for his usual unsupported pronouncements of doubt.
Grrr. Mooney was appropriately assertive, but it sounds like we need to go to new levels of aggression: next interview, bring duct tape and a clothesline. Shut the interviewer up, and charge right into the data. I can’t believe Flatow let Bethell get away with that crap.
The diagram above shows the early cleavages of the embryo of the scaphopod mollusc, Dentalium. You may notice a few peculiarities: the first cleavage is asymmetric, producing a cell called AB and a larger sister cell, CD. Before the second division, CD makes a large bulge, called a polar lobe, and it almost looks like it’s a three-cell stage—this is called a trefoil embryo, and can look a bit like Mickey Mouse. The second division produces an A, a B, a C, and a D cell, and there’s that polar lobe, about as large as the regular cells, so that it now resembles a 5-cell embryo. What’s going on in these animals?
Maternal effect genes are a special class of genes that have their effect in the reproductive organs of the mutant; they are interesting because the mutant organism may appear phenotypically normal, and it is the progeny that express detectable differences, and they do so whether the progeny have inherited the mutant gene or not. That sounds a little confusing, but it really isn’t that complex. I’ll explain it using one canonical example of a maternal effect gene, bicoid.
