Life Sciences
clock | August 21, 2006Why Piglets Shudder To Keep Warm:
Brown fat helps newborn mammals maintain their body temperature by burning fat, which converts into heat. The protein UCP1 (Uncoupling Protein 1) has a key role in this energy conversion, which takes place in the cell mitochondria.
No brown fat or UCP1 protein has been found in domesticated pigs, however. In their study, Berg and colleagues show that the UCP1 gene was shut down about 20 million years ago in an ancestor of the wild boar. They identified four different mutations, each of which would be sufficient to knock out the function of the protein.
This…
evolgen | August 21, 2006During the early part of the twentieth century, biological research was somewhat disjointed. Naturalists studied organisms and populations in the wild; geneticists were working out the mechanisms of heredity; and other researchers were figuring out how animals develop from a fertilized egg to an adult. One important union occurred when the naturalists and geneticists came together to study the genetics of natural populations. This led to the field of population genetics, which is still providing us with insights into the mechanisms of evolution today. Another major advance occurred when…
revere | August 20, 2006Sometimes on Sunday I catch up on my backed up journal reading. High profile journals like Nature and Science are great except for one major defect: they come once a week, every week. They tend to pile up. So I browse them, looking for interesting articles or just satisfying my somewhat eclectic scientific interests. No surprise, with a Freethinker Sermonette due, the article by Miller, Scott and Okamoto, "Public Acceptance of Evolution" would catch my eye (Science 11 August 2006:Vol. 313. no. 5788, pp. 765 - 766):
Beginning in 1985, national samples of U.S. adults have been asked whether the…
clock | August 18, 2006One of the several hypotheses floating around over the past several years to explain the phenomenon of repeated wake-up events in hibernating animals although such events are very energy-draining, is the notion that the immune system needs to be rewarmed in order to fend off any potential bacterial invasions that may have occured while the animal was hibernating:
Now, a group of researchers provided a mathematical model that supports this hypothesis:
"A habit in some animals to periodically wake up while hibernating may be an evolutionary mechanism to fight bacterial infection, according to…
clock | August 18, 2006Chossat's Effect in humans and other animalsThis April 09, 2006 post places another paper of ours (Reference #17) within a broader context of physiology, behavior, ecology and evolution.
The paper was a result of a "communal" experiment in the lab, i.e., it was not included in anyone's Thesis. My advisor designed it and started the experiment with the first couple of birds. When I joined the lab, I did the experiment in an additional number of animals. When Chris joined the lab, he took over the project and did the rest of the lab work, including bringin in the idea for an additional…
retrospectacle | August 18, 2006
First off, some exciting news for Grey Matters: Dr. Irene Pepperberg has agreed to do an interview for the series, likely in September.
Today's feature on Grey Matters is regarding the neural architecture underlying the learning and memorization of songs and sounds in birds. Hopefully it will help address a wide-spread, but fallacious notion that avian brains are too small and unsophisticated for complex learning and memory. Avian brains are not a primitive version of mammalian brains, but rather evolved in parallel under similar environmental conditions. The brain regions which process and…
loom | August 15, 2006Whales are beautifully ridiculous. They are majestic divers, in some cases plunging nearly two miles underwater. And yet sooner or later they must rise back to the surface to breathe air. They breathe through a rather ridiculous-looking hole on top of their head. Unlike fish, which often reproduce by spraying millions of eggs and swimming away, whales give birth to one calf at a time, which they proceed to nurse for months. Some whales are like underwater bats, shrieking through their blowholes and listening to the echoes. And perhaps most ridiculous of all are whales that turn themselves…
clock | August 15, 2006
This post from March 27, 2006 starts with some of my old research and poses a new hypothesis.
The question of animal models
There are some very good reasons why much of biology is performed in just a handful of model organisms. Techniques get refined and the knowledge can grow incrementally until we can know quite a lot of nitty-gritty details about a lot of bioloigcal processes. One need not start from Square One with every new experiment with every new species. One should, of course, occasionally test how generalizable such findings are to other organisms, but the value of models is…
pharyngula | August 14, 2006Tanystylum bealensis male, ventral view, showing eggs and instar 1 (protonymphon) on
ovigerous legs. in. 1, instar 1 (protonymphon); pa, palp; pr, proboscis; 1, first walking leg; 2, second
walking leg; 3, third walking leg; 4, fourth walking leg.
Surely, you haven't had enough information about pycnogonids yet, have you? Here's another species, Tanystylum bealensis, collected off the British Columbian coast. That's a ventral view of the male, and those bunches of grapes everywhere are eggs and babies—males do the childcare in this group. These animals also live in relatively shallow water,…
goodmath | August 14, 2006A reader sent me a copy of an article posted to "chat.anncoulter.com". I can't see the original article; anncoulter.com is a subscriber-only site, and I'll be damned before I *register* with that site.
Fortunately, the reader sent me the entire article. It's another one of those stupid attempts by creationists to assemble some *really big* numbers in order to "prove" that evolution is impossible.
>One More Calculation
>
>The following is a calculation, based entirely on numbers provided by
>Darwinists themselves, of the number of small selective steps evolution would
>have to…
tsmith | August 14, 2006 The control and eventual eradication of the smallpox virus from the wild is one of the most heralded success stories in all of public health. Indeed, smallpox has played a central role in the history of vaccination. Even prior to Edward Jenner's use of the related cowpox virus to protect against smallpox disease, it was known that inoculation with materials from an infectious smallpox pustule or scab (dubbed "variolation") could protect an individual from death due to smallpox, generally resulting instead in a mild form of the illness. Jenner's observation that milkmaids seemed to be…
pharyngula | August 13, 2006
Reading through Good Math, Bad Math, I saw a classic example of creationist foolishness: a fellow who insists that math will vindicate the Bible by proving that π = 3. It reminded me of this old post where a creationist had the thread jumping in her need to prove that the story of Jacob and Laban actually demonstrated a valid form of biblical genetics. So here it is; the original comments are also amusing.
It's not just the US that is infested with creationists; take a look at Canadian Christianity. Like their southern brethren, they seem to be greatly concerned about homosexuals and…
clock | August 11, 2006 Before the days of Times Select, David Brooks used to provoke long rants twice a week. This post from October 24, 2004 is one of those.
David Brooks is so predictable. Every week or so, he comes up with a new scheme to explain the polarization of America. Each time he uses what seems to be different criteria, but are really just different terms. The funniest (and the worst) so far was the division into "spreadheet" and "paragraph" people (link: http://www.mercurynews.com/mld/mercurynews/news/opinion/9660863.htm?1c ). This week, he came up with yet another one (link: http://www.nytimes.com/…
razib | August 11, 2006The headline says, Evolution Less Accepted in U.S. Than Other Western Countries, Study Finds, but here is the money shot: "The only country included in the study where adults were more likely than Americans to reject evolution was Turkey." My liberal friends often make fun of the "inbred" Creationist yokels who inhabit the hinterlands of this great nation, and contrast them with the sophisticated secularity over the waters. On the other hand, many Americans, especially culturally sensitive progressives declare that the EU should let Turkey in to show that it is "open minded" and not a "…
pharyngula | August 10, 2006We are so screwed.
That's the result of a new survey of people's attitudes toward evolution. Notice where the United States lies: nearly dead last. We beat Turkey.
There was more to this study than just asking whether a person agreed with the statement that "Human beings, as we know them, developed from earlier species of animals." They also collected other data on age, gender, education, genetic literacy, religious belief, attitude toward life, attitude toward science and technology, belief in science and technology, reservations about science and technology, and political ideology, and…
pharyngula | August 9, 2006
I've been having some fun with a bizarrely didactic creationist comic book by one Jim Pinkoski that purports to explain all the flaws in evolutionary biology. What it really is is the most astounding collection of bad creationist arguments I've ever seen gathered in one place. I've been trying to slog through rebuttals, but unfortunately, it's like every word and phrase is so far off kilter that it's going to take me forever to get through it. One putative "problem" that I've already dealt with is that we only use 10% of our brains, and so scientists are stupid and untrustworthy, but here'…
j7uy5 | August 9, 2006James Robbins, contributing editor at the National Review Online,
thinks global warming is a good idea. This is proclaimed in
his article, Hooray for Global Warming.
This is another version of the "CO2
is life" meme. And like "CO2
is life," it is utter nonsense. Anyone who would say that
fails to grasp a critical point about climate science. I've
never actually done a fisking, and I do not particularly care for it as
a literary form, but this one begs for it...
href="http://article.nationalreview.com/?q=ZTJmNWI4N2Y2NTBmY2E3ZTIzZjcxM2IzM2ZjNjRkYWI=">Hooray
for Global WarmingSurf’s up…
scientificactivist | August 8, 2006From the archives:
(13 January 2006) What do global warming and epidemic diseases have in common? Apparently they have a lot, at least when it comes to amphibians.
Microorganisms have a knack for showing up in unexpected places. In the 1980s, two scientists discovered a bacterium called Helicobacter pylori that causes over 80% of stomach ulcers, once thought to be primarily caused by stress. This turned medical dogma upside-down and earned them the 2005 Nobel Prize in Physiology or Medicine . Even microorganisms aren't safe from other microorganisms, with bacteria, for example under constant…
oracknows | August 7, 2006It occurred to me over the weekend that I hadn't updated my Medicine and Evolution series in a while. A couple of weeks ago, I wrote about a couple of clueless creationists who had wildly misinterpreted a recent paper about how the cornea prevents blood vessels from growing into it from the surrounding sclera as "evidence" against evolution, basing his conclusion on, in essence, a single sentence from the abstract of the paper. It turns out that my humble efforts attracted the attention of an editor for American Academy of Ophthalmology, who was kind enough to forward to me a fascinating…
grrlscientist | July 31, 2006
Taking the Plunge
(Female Belted Kingfisher, Ceryle alcyon).
Image appears here with the kind permission of the photographer, David Seibel, who writes;
"I never realized, until freezing the motion with my camera, that kingfishers dive from
their perch with wings completely folded. I've captured woodpeckers doing the same
thing." [email David]
Birds in Science
A biologist studying wild songbirds in New York State reported that all 178 woodland birds he tested last year had unusually high levels of mercury in their blood and feathers, a sign that the toxic chemical has spread farther in the…