Organisms
pharyngula | September 30, 2007Chris Clarke callously infected me with a meme. I'm supposed to answer these five questions.
An interesting animal I had
An interesting animal I ate
An interesting animal in the Museum
An interesting thing I did with or to an animal
An interesting animal in its natural habitat
My first thought was, "Dude! These are awfully personal questions. Why are you asking for these intimate details of my sex life?" But then I noticed that he brought up my little friend Snowball (you may not want to read that), and all of his stories were about non-human animals. Oh. Never mind. That's completely…
pharyngula | September 28, 2007Helicocranchia sp.
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
pharyngula | September 23, 2007
One concept that is sometimes used in developmental biology is the idea of the "master control gene" or "master switch" — a single gene whose expression is both necessary and sufficient to trigger activation of many other genes in a coordinated fashion, leading to the development of a specific tissue or organ. It's a handy concept on which to hang a discussion of transcription factors, but it may actually be of rather limited utility in the real world of molecular genetics: there don't seem to be a lot of examples of master control genes out there! Pax-6 is the obvious one, a gene that…
pharyngula | September 21, 2007Feathers only rarely fossilize, so the distribution of feathers in dinosaurs is difficult to determine. Sometimes feathers mark the bones, though, and bones do preserve well. Here's an example: the forearm of a Velociraptor retains an array of small bony bumps evenly spaced along its length. What could they be?
In the photo below is the homologous bone of a turkey vulture, showing similar bumps. They are quill knobs, or places where a ligament anchors the root of a secondary feather directly to the bone. Their presence is an indicator of the presence of a large feather — something more than a…
pharyngula | September 21, 2007Deep sea squid, unidentified species
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
pharyngula | September 15, 2007People, don't do this to me. I've got all this work I've got to get done so that I'm free to go on a date this evening, and you keep sending me these distractions. Like, for instance, this link to a collection of Marine Invertebrate Video and Film Stock Footage. Cephalopods and nudibranchs and crustaceans and salps, all categorized (there's even an invertebrate mating category! With 421 clips! It's free porn!) and with thousands of high resolution videos. The previews are all free, but you can also license HD video of these beautiful action shots.
I will be disciplined, though. I'm closing…
pharyngula | September 14, 2007Sepioteuthis sepioidea
Figure from Cephalopods: A World Guide (amzn/b&n/abe/pwll), by Mark Norman.
pharyngula | September 7, 2007Glowing sucker octopus
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
pharyngula | September 6, 2007
The vertebrate jaw is a product of evolution — we have a serially repeated array of pharyngeal structures as embryos (and fish retain them in all their bony glory as gill arches), and the anterior most arch is modified during our development to form the jaws. The fact that they're serially repeated raises an interesting possibility: what if, instead of just the one developing into a jaw, others were transformed as well? You could have a whole series of jaws!
One animal has done exactly that. The moray eel has modified one of the more posterior pharyngeal arches into a second pair of jaws,…
pharyngula | August 31, 2007Vampyroteuthis gazes at you with its terrible ancient eye…
Close it, please, for the love of heaven, close it!
Vampyrotheuthis infernalis
JEBUS! It's got a sphincter for an eye! OPEN IT AGAIN! OPEN IT AGAIN!
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
pharyngula | August 30, 2007Admit it: if you were walking along and saw this on the trail, you'd stop and turn back, wondering if Shelob was sneaking up behind you.
Bug girl has the explanation.
pharyngula | August 26, 2007I heard a rumor that yesterday was Mrs Tilton's birthday, so here's a belated gift: a pretty picture of an exotic Brazilian salticid batting its eyelashes at the viewer.
(click for larger image)
(Take that, Cute Overload!)
pharyngula | August 24, 2007
Some of you may have never seen an arthropod embryo (or any embryo, for that matter). You're missing something: embryos are gorgeous and dynamic and just all around wonderful, so let's correct that lack. Here are two photographs of an insect and a spider embryo. The one on the left is a grasshopper, Schistocerca nitens at about a third of the way through development; the one on the right is Achaearanea tepidariorum. Both are lying on their backs, or dorsal side, with their legs wiggling up towards you.
There are differences in the photographic technique — one is an SEM, the other is a DAPI-…
pharyngula | August 24, 2007Stauroteuthis syrtensis
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
pharyngula | August 21, 2007Yesterday's discussion of future biological advances that will piss off the religious right had me thinking about other innovations that I expect will happen within a few decades that might just cause wingnuts to freak out. First thing to come to mind is that it will be something to do with reproduction, of course, and it will scramble gender roles and expectations…so, how about modifying men to bear children? It sounds feasible to me. Zygotes are aggressive little parasites that will implant just about anywhere in the coelom — it's why ectopic pregnancies are a serious problem — so all we…
pharyngula | August 20, 2007If it existed, it might also be profoundly autistic and … diabetic? So science cannot disprove the existence of a soul, but one thing we're learning is how much valued human properties such as love and attachment and awareness of others are a product of our biology — emotions like love are an outcome of chemistry, and can't be separated from our meaty natures.
The latest issue of BioEssays has an excellent review of the role of the hormone oxytocin in regulating behaviors. It highlights how much biochemistry is a determinant of what we regard as virtues.
Anyone with a little familiarity with…
pharyngula | August 17, 2007Wonderpus is a spectacular cephalopod that has appeared a few times on the Friday Cephalopod. How can you forget an octopus with this kind of psychedelic color?
Wunderpus photogenicus
Now a reader has sent me a link to the formal taxonomic description of Wunderpus photogenicus, and we can get more details on this beautiful animal.
A taxonomic paper is more than a couple of gosh-wow pictures and the announcement of a spiffy name — it's a fairly detailed description of as much as is known about the species, with special attention paid to the technical features that distinguish this species from…
pharyngula | August 17, 2007(click for larger image)Vampyroteuthis infernalis
Figure from The Deep(amzn/b&n/abe/pwll), by Claire Nouvian.
from Kim Reisenbichler © MBARI 1995
pharyngula | August 13, 2007If you've got a reasonably robust gut, you might be able to handle following this link to a movie showing the intimate relationship between a man and his botfly larvae.
If you can't appreciate the beauty of large maggots, well, no, you might not want to click. Really. I am not to blame if you disregard my recommendation.
pharyngula | August 10, 2007Here is an excellent article on the biology of sexual orientation. We all know this is a contentious issue — are we born with an orientation, or is it a 'choice' that people make? — and the article just lays the facts out for us and points out some of the lacunae in our knowledge.
First, I'll confess to my own position on that nature-nurture debate: it's both and it's neither, and the argument is misplaced. There is no template on the Y chromosome that triggers a sexual response when Pamela Anderson enters the visual field, but there almost certainly are general predispositions that are a…