Whoa…watch this phenomenal video of the Vampire Squid. They’ve caught it feeding and using a few sneaky tricks to escape predators.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
Whoa…watch this phenomenal video of the Vampire Squid. They’ve caught it feeding and using a few sneaky tricks to escape predators.
I mentioned before that IDEA clubs insist that expertise is optional; well, it’s clear that that is definitely true. Casey Luskin, the IDEA club coordinator and president, has written an utterly awful article “rebutting” part of Ken Miller’s testimony in the Dover trial. It is embarrassingly bad, a piece of dreck written by a lawyer that demonstrates that he knows nothing at all about genetics, evolution, biology, or basic logic. I’ll explain a few of his misconceptions about genetics, errors in the reproductive consequences of individuals with Robertsonian fusions, and how he has completely misrepresented the significance of the ape:human chromosome comparisons.
We just had one of these!
Well, just to flesh it out a little more with some random links, here are some photos. I was told the second one made someone think of me (warning: body modification!). And, jebus help me, for some reason I thought this photo was very sexy. Or appetizing. I don’t know, something in the midbrain flickered.
Oh, and several of us sciencebloggers were interviewed for an article by Eva Amsen on “Who benefits from science blogging?” It doesn’t mention the benefit of people sending you pictures that tickle the cingulate.
Now the physicists are putting together carnivals: it’s Philosophia Naturalis #1. Hey, aren’t these carnivals kind of like…stamp collecting?
We are all familiar with the idea that there are strikingly different kinds of eyes in animals: insects have compound eyes with multiple facets, while we vertebrates have simple lens eyes. It seems like a simple evolutionary distinction, with arthropods exhibiting one pattern and vertebrates another, but the story isn’t as clean and simple as all that. Protostomes exhibit a variety of different kinds of eyes, leading to the suggestion that eyes have evolved independently many times; in addition, eyes differ in more than just their apparent organization, and there are some significant differences at the molecular level between our photoreceptors and arthropod photoreceptors. It’s all very confusing.
There has been some recent press (see also this press release from the EMBL) about research on a particular animal model, the polychaete marine worm, Platynereis dumerilii, that is resolving the confusion. The short answer is that there are fundamentally two different kinds of eyes based on the biology of the cell types, and our common bilaterian ancestor had both—and the diversity arose in elaborations on those two types.
Everyone knows the story of Konrad Lorenz and his goslings, right? It was a demonstration of imprinting: when young animals are exposed to a stimulus at a critical time, they can fix on it; Lorenz studied this phenomenon in geese, which if they saw him shortly after hatching, would treat him like their mother, following him around on his walks. Similarly, many animals seem to experience sexual imprinting, where they acquire the sexual preferences that will be expressed later on.
I just ran across a charming short letter about imprinting in cephalopods, and somehow the story seems so appropriate. Imprint a young, freshly hatched cuttlefish on something, and they don’t treat it like Mom, and they don’t later want to mate with it—they want to eat it. Lorenz was lucky he was working on birds rather than cephalopods.
The experiment is straightforward. Cuttlefish normally prefer to eat shrimp over crab. If, the day after hatching, small crab are put in the tank with the hatchlings for at least two hours, and then removed (the crabs are not eaten), then 3 days later when tested again, the cuttlefish will prefer to kill and eat crabs over shrimp. The procedure is very specific: they have to be exposed to crab for at least two hours, within 2 hours after sunrise on their first day after hatching.
The paper has a good, succinct description of why many animals would have this mechanism:
Precocial animals, like domestic
chicks and cuttlefish, which are
independent within hours of hatch
or birth and which receive no
posthatch parental care have
two options for acquisition of
information: bring it into the world
with you (unlearned preferences
for food, sexual partners and so on)
or pick up the information as you go
(trial and error learning). Imprinting
allows something in between:
a certain degree of flexibility in
response, useful for learning
information for which the timing is
likely to be predictable—food
seen in first few hours of life,
sibling/parents seen during
juvenile stages—but in which
specifying the exact details of
the experience is not useful.
An evil man could think of many nefarious things to do with this bit of information, I think.
Healy SD (2006)Imprinting: seeing food and eating it. Curr Biol.16(13):R501-502.
True confession: I try to watch the medical drama House when I can. It’s lead character is an acerbic and brilliant atheist M.D. (played by Hugh Laurie, a comedic actor—which was a smart casting decision), and the humor is snarky and dark. That’s just the kind of thing I enjoy. It’s been going downhill, I think, because the episodes have gotten far too predictable—there’s always a weird illness which is handled via increasingly wild semi-random diagnoses that always, and I definitely mean always, ends with the complete cure of the patient. The infallibility is wearing a little thin.
Last season’s finale almost made me give up. They turned the gross-out factor up to 11 (exploding testicles and eyeballs popping out), and resolved everything with the lamest, laziest television cliche: it was just a dream. I hoped it was just an aberration.
Last night’s episode, though, blew it. I have lost faith in House. <spoilers below>
The newest edition of the Tangled Bank, Tangled Bank #62—Travel Bingo edition, is now up at the Hairy Museum of Natural History. The editor went all out for this one and made custom icons for each entry: don’t you wish you’d submitted something now?
May I direct your attention this way? If you really want to make a case that GW Bush has been hurting American science, look where it really counts: follow the money. The Scientific Activist has the numbers, and it’s rather dramatic how research funding has dwindled over the years.
This week, my students are thinking about SIDS,
aging,
Christiane Nusslein-Volhard,
oncogenes,
hunger,
individuality,
worm movies,
obesity,
sunscreen, and whether to
divide or die. A fairly typical set of undergraduate concerns, right?
They’ve all also been reading chapters 3 and 4 of Carroll’s Endless Forms Most Beautiful, and their summaries are here: α,
β,
γ,
δ,
ε, and
ζ.
If you missed it, here’s Last week’s digest and a brief explanation of what it’s all about.
