Organisms
pharyngula | January 29, 2008On Tuesdays, I have back-to-back labs from noon until six…in genetics. I've been juggling flies since early December, prepping stocks for our crosses, so when I saw this cartoon I was surprised. Does Darby Conley have a background in fly genetics? It's perfect!
pharyngula | January 26, 2008So what if they want to chew your face off? They're being the best Japanese Giant Hornets they can be.
pharyngula | January 18, 2008Something different this week: click the image and see David Gallo present a series of short video clips of cephalopods in action.
pharyngula | January 17, 2008
The capybara is the current champion for rodents of unusual size — it weighs about 60kg (about 130 pounds); another large rodent is the pakarana, which weighs about a quarter of that. Either one is far too much rattiness for most people to want hanging around.
Now there's another king of the rodents: Josephoartigasia monesi, which is estimated to have tipped the scales at about 1000kg, over a ton. Don't worry about getting bigger rat traps; these beasties have been extinct for perhaps 2 million years. I've put a few pictures from the paper describing this new species below the fold.
This is…
pharyngula | January 15, 2008
Hagfish are wonderful, beautiful, interesting animals. They are particularly attractive to evolutionary biologists because they have some very suggestive features that look primitive: they have no jaws, and they have no pectoral girdle or paired pectoral fins. They have very poorly developed eyes, no epiphysis, and only one semicircular canal; lampreys, while also lacking jaws, at least have good eyes and two semicircular canals. How hagfish fit into the evolutionary tree is still an open question, however.
There is a strong temptation to see hagfish as representing an earlier grade of…
pharyngula | January 11, 2008How sweet: this octopus got a Mr Potato Head for Christmas, and now he won't let anyone take it away.
Hasbro really must come out with a new line of Mr Potato Head features that includes beaks and suckers and tentacles, and then they'll have the cephalopod market completely locked up.
pharyngula | January 2, 2008
Neurulation is a series of cell movements and shape changes, inductive interactions, and changes in gene expression that partitions tissues into a discrete neural tube. It is one of those early and significant morphogenetic events that define an important tissue, in this case the nervous system, and it's also an event that can easily go wrong, producing relatively common birth defects like holoprosencephaly and spina bifida. Neurulation has been a somewhat messy phenomenon for comparative embryology, too, because there are not only subtle differences between different vertebrate lineages in…
pharyngula | December 28, 2007It's still Friday, isn't it? Some of you have noticed there was some screw-up in post scheduling, which has been fixed now…and here at last is the Friday Cephalopod.
Sepia sp.
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | December 21, 2007Sepiadarium sp.
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | December 19, 2007We've got a splendid new analysis of a southeast Asian artiodactyl from the Thewissen lab that reveals that these little deer-like animals are a sister taxon to whales — so this pushes our understanding of the ancestry of whales yet further back. Carl Zimmer has already described the essentials — I'll just show a few pictures of the fossils.
If you're read Zimmer's At the Water's Edge, you already know that one of the key diagnostic features of cetaceans is the large auditory bulla at the bottom of the skull. It's a distinctive bony capsule that contains the ear structures, and which also has…
pharyngula | December 15, 2007
Those of you who have been pregnant, or have been a partner to someone who has been pregnant, are familiar with one among many common consequences: lower back pain. It's not surprising—pregnant women are carrying this low-slung 7kg (15lb) weight, and the closest we males can come to the experience would be pressing a bowling ball to our bellybutton and hauling it around with us everywhere we go. This is the kind of load that can put someone seriously out of balance, and one way we compensate for a forward-projecting load is to increase the curvature of our spines (especially the lumbar…
pharyngula | December 14, 2007
On the one hand, this is a strange tale of mutant, bisexual, necrophiliac flies, and you've got to love it for the titillating nature of the experiments. But on the other, much more interesting hand, it's a story about drilling down deeply into the causes of a complex behavior, and tracing it to a single gene product — and it also reveals much about the way the chemicals sloshing about in the brain can modulate responses to stimuli. Work by Grosjean and others on a simple Drosophila mutant, genderblind, which causes flies to be indiscriminate about gender in their courtship, opens up a…
pharyngula | December 14, 2007Octopus kagoshimensis
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | December 12, 2007
I've known that scorpions have fluorescent cuticles — if you go out into the desert with a black light and shine it on the ground, the scorpions will often glow green and blue and be easy to spot. I had no idea that many spiders exhibit the same phenomenon, but there they are, glowing away. I may have to visit my local head shop (in Morris? Hah!) and get some black light bulbs to see what the fauna in my living room is up to.
Fluorescence is actually a fairly common property: all it requires is a molecule called a fluorophore that can absorb and capture transiently photons of a particular…
pharyngula | December 7, 2007Sepia latimanus
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | December 4, 2007I have to second Steve — this is an amazing blog, The Daily Coyote. A woman and a cat living in remote Wyoming have a friend, a young coyote.
This has got to be a frightening relationship. That's a place where coyotes are shot on sight, with no remorse … maybe if a few more people read about Charlie, though, they won't be so quick to kill.
pharyngula | December 3, 2007Two big specialty science carnivals are up today: Circus of the Spineless #27
and
Encephalon #37. Take your pick, invertebrates or nervous systems…or read them both.
pharyngula | November 16, 2007
We had a seminar from Marco Restani of St Cloud State University yesterday — he's a wildlife biologist who talked about Tasmanian Devils. Just a little tip: don't ever invite wildlife biologists or conservation ecologists to give talks. They are the most depressing people in the world, and they really make it hard to hide away from the ugly realities. This talk was no exception: the Tasmanian Devil is in big trouble, and is facing at least two major threats, each of which may be sufficient to wipe them out. And just looke at that guy! He's adorable! How can you let them go extinct?
The first…