biology
moleculeoftheday | February 8, 2007Buffers are a bit tricky. In biology, a buffer contains at least one ingredient: something to set the pH. This means having something that ionizes (takes on or loses a proton) at about the pH you want. You can set the pH within about one unit of this value (the pKa). This constraint exists because of thermodynamics: anything ionizable will absorb protons or hydroxide equivalents around its pKa, without changing pH much. In the strict, correct sense, this is a buffer.
Really, though, what most biologists call a "buffer" is all the supporting players in a solution - the buffering agent,…
tfk | February 8, 2007The WWF reports that researchers in Turkmenistan spotted a striped hyena in a park. The species once ranged from Africa through to India and Central Asia, but habitat degradation and declining prey populations have caused their Asian populations to decline.
This discovery in a protected area of Turkmenistan suggests that conservation measures are successfully protecting even top predators which require more space and resources than many other species.
Striped hyenas (Hyaena hyaena) are a different genus from the spotted hyena (Crocuta crocuta). Striped hyenas are generally solitary, or live…
tfk | February 6, 2007A paper in Science shows that certain grasses found near hotsprings in Yellowstone can only persist thanks to a three-way symbiosis. Márquez et al. (2007) showed that the grasses could not survive near hotsprings unless a symbiotic fungus was growing in them. No, not a true mushroom, I only put that in the title to befuddle internet perverts.
These sorts of interactions between plants and fungi are common. There are stories of plants so interlaced with their fungal symbiote that samples of the plant taken for DNA analysis wound up being classified as fungae in systematic analyses. These…
revere | February 2, 2007If H5N1 is going to "go pandemic" it has to be transmissible from person to person. This occurs, but rarely. Why? The 1918 virus was not only lethal but easily transmissible. What's the difference between the 1918 pandemic strain and all the H5N1 strains we've seen so far?
One of the theories was that H5N1 didn't transmit readily because it didn't infect readily, and the explanation for that was that the avian versions hooked on to cellular receptors that are readily accessible in birds but not in humans. We've discussed the underlying science frequently (here [first in five part series, with…
tfk | February 1, 2007Retrospectacle asks Is a Species' Survival Inherently Valuable?
My answer is "yes," but I agree with Shelley that the question is tricky. If someone found a way to make chiggers go extinct, would I really mind that much? Do I really care that this or that dam would make some guppy go extinct?
Much as I want to believe that a world without chiggers would be a better place, I ultimately have to conclude that it wouldn't be.
There are two books that I think are essential to understanding where I'm coming from. The End of Nature by Bill Mckibben lays out one important part of the argument.…
omnibrain | January 31, 2007Here's the basic story...
New work by a team of researchers has shed light on why hallucinogenic compounds cause altered states in creatures. It has long been known that hallucinogenic compounds have a high affinity for a certain receptor in the central nervous system (5-HT2A, or 2AR), and that when these receptors are blocked, the hallucinogenic side effects are mitigated. What has remained a mystery is why other non-hallucinogenic compounds with a similar affinity for these 2ARs do not produce similar side effects.
How do you know a mouse is tripping balls? It's not like you can show them…
evolgen | January 30, 2007I straddle the line between being a population biologist and a molecular geneticist. That's a self-congratulatory way of saying that I am an expert in neither field. But existing in the state I do allows me to observe commonalities shared by both. For example, both fields have terminology (or what the uninitiated would call jargon) that lack sufficient definitions.
Amongst my minimal postings from last week were included a couple of riffs on species and speciation (the first, the second) getting at the lack of a coherent definition of species. My conclusion is that there is not, nor will…
omnibrain | January 30, 2007 GW Pharmaceuticals has developed a diet drug derived from Marijuana which suppresses the appetite. This is especially surprising for obvious reasons - perhaps a little ironic?!
Clearly the marijuana plant contains many many different compounds - but who would have thought that one of them suppressed the urge to gorge yourself on cheeze doodles and icy pops. The drug will soon be entering into human trials to combat obesity.
Don't get too exited about getting high on the drug though since that doesn't happen to be one of the side effects. Well...that is unless you want to find the secret…
omnibrain | January 29, 2007Lincoln seemed to have all sorts of problems - bipolar depression, unipolar depression, thyroid problems, bad gas, gargantuanism - you name it and someone has claimed he had it! But now it looks like, according to a study of worms, his nerves shattered?
Abraham Lincoln may have suffered from a genetic disorder that literally shattered his nerves, a new study on worms suggests.
Many of the president's descendants have a gene mutation that affects the part of the brain controlling movement and coordination, researchers discovered last year. The mutation prevents nerve cells from "communicating…
omnibrain | January 28, 2007 Check out the brains of mice on drugs. This site is a very strange one to say the least- it starts with a bunch of high mice in a club of sorts just struggling to stand up. Then the interactive flash demo starts in which you have to drag a mouse into a comfy chair which transports it into a weird device that shows what's happening to the mouse's brain depending on what it snorted, smoked, or injected earlier.
Freakin' weird - a wee bit trippy ;). Especially from an academic institution.
Check out the Mouse Party.
omnibrain | January 27, 2007Ok.. so perhaps it's not a total museum dedicated to homosexual animals - but it looks like a pretty good sized exhibit. Unless you're in Norway you might be missing the exhibit though. Anyone want to sneak some photos for us?
From male killer whales that ride the dorsal fin of another male to female bonobos that rub their genitals together, the animal kingdom tolerates all kinds of lifestyles.
A first-ever museum display, "Against Nature?," which opened last month at the University of Oslo's Natural History Museum in Norway, presents 51 species of animals exhibiting homosexuality.
Here'…
grrlscientist | January 25, 2007
Herring Gull, Larus argentatus, eating a starfish.
Image: Drew Weber.
As long as you send images to me (and I hope it will be for forever), I shall continue to share them with my readership. My purpose for posting these images is to remind all of us of the grandeur of the natural world and that there is a world out there that is populated by millions of unique species. We are a part of this world whether we like it or not: we have a choice to either preserve these species or to destroy them in search of short-term monetary gains. But if we decide to destroy these other life forms, the…
omnibrain | January 25, 2007From the Improbable Research blog and Reuters:
BEIJING, China (Reuters) -- Hundreds of chickens have been found dead in east China -- and a court has ruled that the cause of death was the screaming of a four-year-old boy who in turn had been scared by a barking dog, state media reported on Wednesday.
The bizarre sequence events began when the boy arrived at a village home in the eastern province of Jiangsu in the summer with his father who was delivering bottles of gas, the Nanjing Morning Post reported.
A villager was quoted as saying the little boy bent over the henhouse window, screaming…
jlynch | January 24, 2007Darren Naish ("Tetrapod Zoology") has joined our merry band. Wander over, say "Hi", and learn about the evolution of vampires.
jlynch | January 24, 2007
A few of my SciBlings have posted on the frilled shark (Chlamysoselachus anguineus) that turned up off Japan. Shelley and PZ have two different videos to check out. A CNN story notes that the species "sometimes referred to as a 'living fossil'
because it is a primitive species that has changed little since prehistoric times." This is a somewhat controversial statement. A few paleontologists claim that the species is a living cladodont shark, but while some of its features (teeth in particular) are like the cladodonts that occupied Devonian seas, Chlamysoselachus has numerous neoselachian…
jlynch | January 24, 2007Our HPS lab meeting discussed historian Peter Dear's The Intelligibility of Nature today and will be continuing to do so next week. One of Dear's statements regarding Darwin is so wrong it is not even funny:
[Darwin] never paused to ask whether the very meaning of the category 'species' might have been radically changed by his theory, in such a way that earlier taxonomic practices would have to be called into question. [p. 96]
This is merely a lead in to me pointing out that John Wilkins has a wonderful post on species that you should check out if you want to know how biologists and…