Archive for July, 2007
Molecular "computations" are essential for the survival of all organisms. To work, the molecules must pinpoint and then bind to specific counterparts while swimming in a thick, erratic molecular stew – a bit like finding a friend in a busy subway station during rush hour.
How do they accomplish this feat?
Dr. Tsvi Tlusty and Yonatan Savir, of the Weizmann Institute, may have found the answer. A simple biophysical model they developed indicates that in picking out the target molecule from a crowd of look-alikes, the recognizer has an advantage if it is slightly off-target. This may appear counterintuitive: why search for a key that does not match its lock exactly, and then require that the imperfect key warp its shape to fit the lock?
But the researchers' model shows that the key's deformation actually helps in discerning the right target. Although the energy required to deform the molecular key slightly lowers the probability of its binding to the right target, it also reduces the probability that it will bind to a wrong one by quite a bit. Thus, the quality of recognition – i.e. the ratio of the right to wrong binding probabilities – increases.
Dawkins is now selling a uniform to all his followers.
You can get yours here. He could probably up some sales if he got Harris, Dennett, Pinker, and Hitchens to join him in a group photo where they all wear the atheist uniform. Then again, maybe it's only for the followers (kind of like the red shirts on Star Trek).
If this happened in the United States, the "pro-science" blogs would undoubtedly be blaming it on the Creationists and religion. Since they can't, I don't expect any "pro-science" blog to mention it.
After suggesting the existence of an evolution tool kit, how would one go about identifying the contents of such a tool kit? We would need to assign the functional role of "˜evolution' to specific genes. Typically, biologists classify genes according to their functional roles. But they don't assign evolution itself as a functional role.
Over at Uncommon Descent, Denyse O'Leary has some fun with Stephen Pinkers "Dangerous Questions." Pinker comes across as an Establishment Guy desperately trying to look dangerous by cutting up his milk toast in a new pattern. After all, he packs his dangerous essay with no less than 22 dangerous questions. Did you get that? 22! That's not SuperDanger, that's SuperDuperDanger. And just how dangerous is this danger-packed essay? It's signed as follows: Steven Pinker is professor in the Department of Psychology at Harvard University. His new book, The Stuff of Thought, will be out in September. Sorry Dr. Establishment, but if any of those questions were truly dangerous, you wouldn't be signing your name to them.
"One finds that time just disappears from the Wheeler-DeWitt equation," says Carlo Rovelli, a physicist at the University of the Mediterranean in Marseille, France. "It is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time"”that the fundamental description of the universe must be timeless." – Here
You are on your horse galloping at a constant speed.
To your left is a very steep drop off and to your right is an elephant traveling at the same speed as you.
In front of you is a zebra and your horse cannot overtake it.
Chasing you from behind is a tiger.
What must you do to get out of this highly dangerous situation?
There's been quite a lot of debate about whether or not Michael Behe has successfully identified the "edge of evolution." But I would like to step back from this debate and pose a more general question to the TT members.
Does evolution have an edge?
In a paper entitled, "On the Very Possibility of Intelligent Design," published in the book, The Creation Hypothesis, back in 1992, William Dembski offered the following thought experiment: Read the rest of this entry »
In his book Endless Forms Most Beautiful, Sean Carroll explains the role of tool kit genes in the development of organisms. Tool kit genes express products that in turn regulate whether or not other genes are turned on during embryological development. As such, most of them are transcription factors that bind to regulatory regions of a gene, regions Carroll refers to as switches. What thus determines whether or not a particular gene is expressed during development is the combination of activated and repressed switches as a consequence of the composition of the tool kit gene products.
The teleological echo of all this can be seen from more than one angle.
If you ask me, Shalini, the self-described "pro-Dawkins evangelical atheist," is becoming increasingly confused. In response to "Don't Call Me Miltant!!," Shalini has this to say:
Over at Telic Thoughts, MikeGene is apparently up in arms over my anti-appeaser post.
This is a classic example of projection.
We've updated our blogroll. First, you'll find Michael Behe's Blog, where Behe responds to his critics. Second, you'll find Thought Provoker's blog and his continued exploration of the Third Choice. Finally, there is mcromer's blog, Science is a method, not a position, which he desribes as follows: "I don't cover ID much, but I talk a lot about the sociology of science and the proper practice of science." Enjoy.