biology
evolgen | April 13, 2007According to Physorg.com, this study on epigenetic inheritance in chickens "shake[s] Darwin's foundation". Who knew inheritance in a flightless bird could induce an earthquake in northern Australia? That's not what they're referring to? They're not claiming that a neo-Lamarckian process could produce seismic activity?
For everyone running around like a chicken with its head cut off (where's my damn rim-shot?), this result is more of a shot at Mendel than Darwin. And it's not all that surprising. Don't get me wrong, it's cool to see the inheritance of acquired characteristics (unless Reed…
aardvarchaeology | April 12, 2007
A Dear Reader who calls themself Ophistokont made me curious about what this intriguing word might mean. It's very rare, with only seven Google hits and no entry in Merriam-Webster. Ophi- should have to do with snakes. -stok- calls stoichiometry to mind, having to do with elements. -ont has to do with being. Something that forms the basic element of a snake-like thing, maybe?
I didn't make that up unaided. Those seven Google hits explain (mostly in German) that an ophistokont is the end of a single-cell being from which its motile flagellum extends. These little whip-like outboard motors…
evolgen | April 12, 2007Sex chromosomes are cool. Because they're cool, I've written about them before. It's cool to trace the origins of sex chromosomes. It's cool to study how they evolve. And it's cool to compare similarities and differences of sex chromosomes within and between taxa. In organisms that use sex chromosomes to determine sex (eg, mammals, Drosophila, and birds), there is a big honking chromosome that looks like most autosomes and a piddly little chromosome that doesn't even recombine. In some organisms, males have one copy of the dinky chromosome (which we call a Y chromosome) and one copy of the…
evolgen | April 11, 2007Those of us who work on non-human systems often grumble about the total disregard human geneticists (that's geneticists who study humans, not humans who are geneticists) have toward non-human research (that's research on non-humans, not non-humans doing research). I get the feeling that plant biologists have the same attitude toward non-plant researchers, and I imagine there is some unwritten chain of superiority wherein you must pay respect to the researchers working on a system "above" you and ignore the research done on a system "beneath" yours -- and, yes, I realize the higher and lower…
revere | April 9, 2007A trip with Mrs. R. to buy something for the kitchen doesn't seem to have much to do with influenza virology, but let me try to make the connection. We're at Williams Sonoma. I'm wandering around, idly looking at various pieces of kitchen equipment and thinking random food thoughts. I'm not looking for anything particular, myself. But as I'm cruising by a set of shelves I see it has books on it. Quite a few of them. All about food and cooking and associated subjects, but books. I stop. I start to browse. Fifteen minutes later Mrs. R. retrieves me. She is going to shop for something else. I…
jlynch | April 8, 2007AP is running a story that the Integrated Taxonomic Information System-Species 2000 Catalog of Life has reached 1,009,000 extant species and expects to reach 1.75 million by 2011. Along with the Tree of Life project, the Catalog of Life offers plenty of information for the budding systematist.
evolgen | April 6, 2007GAME PREVIEW | PRESS CENTER
Yesterday's game between Corporate and Charles Darwin was a battle between free market capitalism and the greatest naturalist of all time. The Corporate team is loaded with the world's top pharmaceutical and chemical companies. Darwin is the author of important works such as On the Origin of Species and The Descent of Man. To find out who came out on top, click through below the fold.
Everyone expected Darwin to start out with a heavy dose of the Origin. And if he didn't come heavy with that, he'd bring The Descent of Man. But Chuck use neither in the opening…
moleculeoftheday | April 3, 2007Retinal is a pigment in your eyes that is necessary for vision. This is why vitamin A is so essential for vision - retinal is just one oxidation state up from retinol or one down from retinoic acid.
Upon absorbing a packet of light, retinal assumes the trans conformation you see above. Normally, it's found in the cis form (as seen here). This conformational change essentially amounts to a finger pushing a lever; some proteins translate it into a nerve impulse, off it goes to your brain, and hey! look! you've got sight!
The whole system is a little more complicated, especially when you add in…
tfk | April 3, 2007Sal Cordova is a fascinating example of the danger facing anyone who ignores Pope's advice "A little learning is a dangerous thing; drink deep, or taste not the Pierian spring: there shallow draughts intoxicate the brain, and drinking largely sobers us again." Sal's latest bungling of knowledge comes when he wonders:
Is evolution of antibiotic resistance by bacteria an example of Darwinism? Such a claim is very suspicious since Darwinism deals mainly with the origin of species.
Answering this question would be easy of "Darwinism" existed in some meaningful sense. But it doesn't.…
omnibrain | April 3, 2007I'm sad to report today that watching panda pornography didn't excite the two pandas enough for them to engage in kinky panda sex. Perhaps the porn built unrealistic expectations for the male panda and the girl panda didn't match his kinky panda fantasies?! Maybe they should have given the girl panda some breast implants and included another girl panda into the mix. [edit by Sandra - or maybe the girl panda doesn't need to change her body, which is fine the way it is, to conform to some artificial panda porn ideal beauty standard.]
Here's the shtick:
After panda porn failed to spark amour,…
tfk | April 2, 2007Within discussions of environmental issues, there are two broad approaches one can take. On one hand there are those who argue that the goal should be the creation and preservation of wilderness free of human influence. This view can be broadly construed as "preservation."
The other major strain favor using human management to ensure that the natural systems maintain the state they enjoyed prior to human involvement. That approach is generally referred to as "conservation."
The differences are instructive. The historic tallgrass prairie was maintained by fire across the broad center of…
evolgen | March 29, 2007Janet pointed me to a post at the Philosopher's Playground about doing away with laboratory courses in the science curriculum. Steve Gimbel, the philosopher doing the playing, teaches at Gettysburg College. He argues that the lab portions of science classes cause non-science majors to avoid those courses and not enroll in any science class not required for graduation. If science courses consisted of more theory and less labs (by theory he means lecture, and, by choosing that word, he indicates he doesn't have much experience in non-physics science courses where the lectures consist of more…
omnibrain | March 27, 2007 It seems that perhaps pandas don't have mirror sex neurons or something?
Chuang Chuang the panda has been spending his days in front of a big-screen television watching panda porn.
Authorities at the Chiang Mai Zoo in northern Thailand hope the images will encourage him to mate with his partner, Lin Hui, and serve as an instructional lesson in how to do it right.
So far, it's been a tough sell, the zoo's chief veterinarian, Kanika Limtrakul, said Tuesday.
"Chuang Chuang seems indifferent to the videos; he has no reaction to what he's seeing on TV," Kanika said. "But we're continuing to show…
tfk | March 27, 2007In one episode of Futurama, Fry traps a giant brain in a book he wrote "a crummy world of plot holes and spelling errors." That's what it feels like to read the antics of Dembski and the gang. The latest offense to reason comes from DaveScot (predictably). Upon reading this:
First, the germ-free animals lived almost twice as long as their conventionally maintained counterparts, and second, the major causes of death were different in the two groups. Infection often caused death in conventional animals, but intestinal atonia frequently killed germ-free animals.
DS immediately thought of…
tfk | March 27, 2007David Tyler wonders Would Linnaeus have waved the banner of phylogenomics? He writes:
It may surprise some, but Newton did not pioneer physics with relativity in mind. It is not necessary to presuppose an equivalence between mass and energy to be a scholar working in this field.
Oh, that isn't what he wrote. Here's what he said:
It may surprise some, but Linnaeus did not pioneer systematics with the tree of life in mind. It is not necessary to presuppose a common ancestor for all living things to be a scholar working in this field.
One of the great scientific/philosophical battles of the…
omnibrain | March 27, 2007I just though you all would be interested in this ;)
There's a new Chinese saying: When life hands you panda poop, make paper.
Researchers at a giant panda reserve in southern China are looking for paper mills to process their surplus of fiber-rich panda excrement into high quality paper.
...
The Chiang Mai Zoo in northern Thailand already sells multicolored paper made from the excrement produced by its two resident pandas. Making paper there involves a daylong process of cleaning the feces, boiling it in a soda solution, bleaching it with chlorine and drying it under the sun.
Here's the…
jlynch | March 23, 2007
This is just a cool photo. Two Melangyna viridiceps mating in mid-air [via Wikipedia].
evolvingthoughts | March 23, 2007
Here is a list of Basic Concept posts in Biology.
Recently Added: The Pharyngula Stage by PZ Myers at Pharyngula; Biomes VII: Temperate Forest by Jeremy Bruno at The Voltage Gate; Mitochondrial Eve and Y-Chromosome Adam, by Mike Dunford at The Questionable Authority
Botany
Development
The Pharyngula Stage by PZ Myers at Pharyngula
Gastrulation in Vertebrates by PZ Myers at Pharyngula
Gastrulation in Invertebrates by PZ Myers at Pharyngula
Neurulation by PZ Myers at Pharyngula
Cell migration by Dan, at Migrations
Ecology
What is Ecology? by Jeremy Bruno at The Voltage Gate
Biomes…
moleculeoftheday | March 23, 2007Epoxides aren't just found in glue and disinfectants (see here and here. They also occur occasionally in nature (not too often, since they're very strained, high-energy structures - this is why they're so reactive and useful). One such example is in JHB3, a "juvenile hormone" found in insects.
Juvenile hormones have several roles, one of which is regulating the development of juvenile insects. A relatively high level of juvenile hormone keeps insects in an immature state, allowing them to grow, but not achieve sexual maturity. Diminished levels of JH allow maturation to adulthood.…