biology
evolgen | September 3, 2007A new article in Nature Genetics brings together two themes that I've blogged about before: human brains and King and Wilson. In fact, I've even already blogged about the article, but this post contains a more thorough treatment of the science.
The long and short of it is that some people think that differences in protein coding sequences can't explain the morphological differences between humans and chimps. Additionally, there are other phenotypes that differ between the species, including cognitive abilities and dietary preferences. There is evidence for adaptive evolution in protein…
grrlscientist | August 31, 2007tags: spider, giant spider web,arachnid, social behavior
Lake Tawokoni State Park rangers (l-r) Mike McCord and Freddie Gowin continue to monitor a giant communal spider web at the park Tuesday, August 29, 2007. Officials at Lake Tawokoni State Park have been watching the growth of a giant communal spider web that has formed in the park over the past several weeks. The giant spider webs are rare for Texas.
Image: Tom Pennington. [Scary wallpaper size]
Have you heard about the spiders that spun a web that is the size of Texas? Well, actually, the web is only the size of two football…
tfk | August 30, 2007At Billy Dembski's blog, Granville Sewell wonders What if we DID find irreducibly complex biological features?:
In any debate on Intelligent Design, there is a question I have long wished to see posed to ID opponents: “If we DID discover some biological feature that was irreducibly complex, to your satisfication [sic] and to the satisfaction of all reasonable observers, would that justify the design inference?”
No, at least not necessarily. It isn't clear why we should make that immediate leap.
There are two related problems with that jump. First, the fact that something meets the…
tfk | August 30, 2007Reposted from the old blog.
Last week we discussed endosymbiosis, the hypothesis that mitochondria and chloroplasts originated as free-living bacteria captured by another cell and essentially enslaved.
This week's Science has evidence of this process at work today. A Secondary Symbiosis in Progress? -- Okamoto and Inouye 310 (5746): 287 -- Science.
The figure labeled A shows the normal adult Hatena. It has a flagellum, an eyespot (the arrow), and all that green chlorophyll. Turns out, as shown in figure B, the eyespot is inherited by only one daughter cell, as is the green. All that stuff…
oracknows | August 30, 2007Alright, after being castigated for being a stereotypical American tourist complaining about the service in restaurants in London, here's an off-the-wall observation that my wife and I have made:
Why is it that there seem to be no squirrels in London?
We've been all over the city now in the last five and a half days (at least, all over central London), and we've been out into the western part of England to see Stonehenge and Bath. Neither my wife nor I have seen a single squirrel. We've seen lots and lots of pigeons. We saw lots and lots of sheep in the English countryside. We haven't seen a…
oracknows | August 29, 2007Vacation time! While Orac is off in London recharging his circuits and contemplating the linguistic tricks of limericks and jokes or the glory of black holes, he's rerunning some old stuff from his original Blogspot blog. This particular post first appeared on June 15, 2005. Enjoy!
One of the criticisms of "intelligent design" (ID) creationism is that it doesn't really offer any new theory or even hypothesis to replace the theory of evolution, which it seeks to supplant (at least in the public schools). It merely exaggerates perceived weaknesses in evolutionary theory and misrepresents…
purepedantry | August 29, 2007That is so gross, yet also very cool.
The cowpea weevil or Callosobruchus maculatus has an arms race that is going between the males and females. This beetle species are promiscuous, and there is a lot of advantage for the males to be the last one to have mated with a particular female in terms of reproductive success.
This issue has spawned a variety of weird behaviors and adaptations. For example, the males have spines on their intromittent organs (read: insect penises) that puncture the females insides. This is to discourage them from mating with other males. In response the females…
moleculeoftheday | August 27, 2007Ellman reagent can be used to quantitate the amount of free thiol present in a protein or other molecule:
It reacts with the free thiol and releases a nitrocarboxythiophenolate, which is bright yellow. You can then quantitate it with a UV-vis.
oracknows | August 19, 2007The answer, apparently, is yes, but only for a very short time.
I guess the whole exploding heads thing when people are exposed to vacuum (Outland) or just the very low atmospheric pressure on Mars (Total Recall) is a bit of an exaggeration.
jlynch | August 18, 2007
Can any one out there identify this little guy for me? Spotted this afternoon fluttering around my yard (suburban Phoenix, AZ) in some distress. If it helps, the grey stripe is approximately a half an inch wide.
Update: Looks like it is a White-lined sphinx (Hyles lineata Fabricius, 1775). More information here. Thanks to Gene Goldring for making the id.
oracknows | August 18, 2007For those of you who missed it, Steve Colbert explains what DNA is with Twisty the DNA Helix:
DNA: It's what makes you you.
I do have to admit, though, that it irritated me when Colbert referred to DNA as a "wonder protein" even though I'm sure it was part of the joke...
revere | August 16, 2007A new paper in the Annals of Internal Medicine underlines a point we have tried to make multiple times (e.g., see here, here and here). Naive and unthought out therapeutic responses to the idea that bird flu kills via a "cytokine storm" is a bad idea. Cytokine storm is also a common feature of sepsis, which accompanies some pneumonia and other infections and has a high case fatality ratio. I haven't read the original paper because I am at the beach where the Annals of Internal Medicine isn't carried at the local convenience store and my internet connection is barely adequate for email, but I…
evolgen | August 14, 2007Peter Lawrence has an opinion piece in Current Biology on the problems with evaluating scientists, amongst other things. He hits upon a few important points, including journal impact factors, the cost of high risk research, hyping up publications, and networking with the right people to improve your publications. One passage was quite salient given a private discussion I've been having with some folks:
Fourth, there is the way that science is done and papers are authored. These measures are pushing people into having larger groups. It is a simple matter of arithmetic. Since the group leader…
jlynch | August 11, 2007ABC (Australia) is reporting that the Yangtze River dolphin or baiji (Lipotes vexillifer) may not be definitely extinct after all (see here and here). Wang Ding - who headed the survey team - is reported as saying:
This is only one survey and...you can’t have a sample in a survey, so you cannot say the baiji all is gone by the result of only one survey. For example, there is some side channels or some tributaries [where] we cannot go because of a restriction of navigation rules, and also we don’t survey during the night-time so we may miss some animals in the Yangtze River. ...
I’m pretty…
aardvarchaeology | August 11, 2007
Last night when I turned out the lights, something the size of a mouse jumped out of a lamp. We've had a bit of summer heat lately, and the balcony door has been open a lot. The creature turned out to be a wart-biter Great Green Bush-cricket female (Dectius verrucivorus Tettigonia viridissima), longer than my little finger and shiny green. I put a plastic box over her and slid a paper under before shooting photos and releasing her into the night. While in the box, she assiduously cleaned her toes with her jaws. A welcome visit.
[More blog entries about insects, photos; insekter, foto,…
jlynch | August 11, 2007
Take eight minutes and watch this. Nice work by the buffaloes when faced by a weak lion defense.
(HT to Tim Sandefur for the link).
purepedantry | August 10, 2007Scientists have thawed samples of bacteria that were frozen in ice for up to 8,000,000 years in order to figure out whether these bacteria would still be viable and whether their DNA is intact. It turns out they are viable, but the longer they were in ice the more their DNA was fragmented. This has implications as to whether life traveled to Earth from a comet or was evolved on site:
However, while some bacteria taken from 100,000-year-old ice reproduced quite readily, cells from the oldest ice multiplied only very slowly and their DNA was badly damaged. Studies of isolated DNA from the…
omnibrain | August 7, 2007From Gary O:
Harvard and MIT researchers have finally addressed a question that has long been puzzling mankind: "If you were a New World monkey, would you rather listen to Russian lullabies or German techno?" In the September issue of Cognition, Josh McDermott and Marc Hauser report finding that both cotton-top tamarins and common marmosets clearly prefer the lullabies. A follow-up experiment concludes that the monkeys actually prefer silence over Russian and German lullabies, as well as Mozart.
Of course no primates (including humans) enjoy listening to Gary Yodel. Here's Gary at Big Bend…
omnibrain | August 6, 2007It was only a matter of time until someone created a sex toy for dogs.
From the description:
A dog is an animal with an enormous sexual appetite which can't be controlled. Many methods consist in artificial ways to stop dogs inborn caractere. These methods like castration or meds are going against the nature laws.
So... is this a joke?
hrynyshyn | August 3, 2007If this isn't a sign of the apocalypse, I don't know what is. Seven legs, double-gendered and bowel-challenged, according to the Herald-Sun. What a way to start your weekend. (Click for full size image.)
I came across the story while reading that Pope B16 says "there is much scientific proof in favor of evolution." Well, that's settles that, then.