Some Science News Tidbits

This one is actually kind of stunning to me. Via BBC,

Charles Weissmann, head of Scripps Florida's department of infectology who led the study, said: "On the face of it, you have exactly the same process of mutation and adaptive change in prions as you see in viruses.

"This means that this pattern of Darwinian evolution appears to be universally active.

"In viruses, mutation is linked to changes in nucleic acid sequence that leads to resistance.

"Now, this adaptability has moved one level down- to prions and protein folding - and it's clear that you do not need nucleic acid (DNA or RNA) for the process of evolution."

The modern synthesis of evolution rolls in the ideas of genetic inheritance (one of the gaping holes in Darwin's theory- which he recognized himself- was that no one had any idea how genetic information was transferred) and aspects of population biology to Darwin's framework. Viruses (which are problematic with respect to the question "are they alive?") still use either DNA or RNA to transit genetic information to "offspring." Now I'm pretty ignorant about molecular biology and organic chemistry, but it seems profoundly important to me that we've discovered a clearly non-living chemistry that can evolve. Granted, it can only do so (as do viruses) in the presence of and by parasitizing living organisms. Still, I have commented before that "life-as-we-don't-know-it" may well be very difficult to recognize. Understanding "protein evolution" might be a way to get insight into non-DNA/RNA inheritance.

As I understand prions, they are essentially abnormal protein molecules that act as catalysts to cause other similar proteins to fold into the abnormal prion form. These misfolded proteins are more stable than proteins in their normal, healthy state, which means that they can't "get better," i.e. return to their normal, less stable state on their own. Please feel free to correct any of my misconceptions or over simplifications; this is something I'm quite curious about.

Another interesting tidbit of trivia about today is that a couple of hours ago, Earth passed perihelion, our annual closest approach to the sun. The idea was also covered at Olelog earlier. It's faint comfort, I suppose, that all things being equal, today would be the brightest sunshine of the year.

Today's APOD is the (very) partial eclipse on New Year's Eve:
I think the thing that really appeals to me about this picture is that the thin haze of clouds is washed out in the direct light of the moon, but enhanced by scatter outside the disk itself. The result makes it look as if the clouds are behind the moon, rather than vice versa. The photo shows nearly the maximum of the eclipse, which was not visible from most of North America.

Note to all my younger, less experienced, readers: gasoline is flammable and smoking is bad for you. Yes, I smoke, but I know it's bad for me. And even before I started smoking, I knew that lighting up while siphoning gas would be a very unwise idea. He's lucky not to have won a Darwin Award. Speaking of which, Jazinator at Dino Jim's Musings, points out a rather gruesome winner of these uncoveted, but all too commonly awarded, failures: a man attempting to steal a gypsum crystal from Mexico's famed Cave of the Crystals was caught underneath one of the gypsum lathes when he broke it off. He wasn't crushed, but he was unable to get it off of himself. And cooked to death in the high temperature, 100% humidity of the cave. Yuck.

Finally, Anatoly N. Perminov, the head of Russia’s space agency, has voiced some rather confusing support for a mission to divert the asteroid Apophis from hitting the earth. At roughly three times the size of the hypothesized Tunguska impactor, this might well be a valid and important project to undertake. The problems are 1: he doesn't seem to know when it might hit. “I don’t remember exactly, but it seems to me it could hit the Earth by 2032.” According to the article in the NYT (one of many, many sources to report this),

In fact, Apophis’s chances of hitting Earth have been downgraded since it was discovered in 2004, NASA said this year. Scientists originally thought the orbit of the 1,000-foot-long asteroid gave it a 2.7 percent chance of hitting Earth on its first approach in 2029, but after studying its path they said it would remain 18,300 miles above the planet’s surface.

On a second approach, in 2036, it was originally given a 1-in-45,000 chance of hitting Earth, but the odds were reduced to 1 in 250,000. The odds of impact on its third approach, in 2068, are 1 in 333,000, NASA scientists say.

Problem 2 sort of takes us back to the Darwin Awards. What if it turns out that its current trajectory carries Apophis safely past earth for the next two or three orbits, but messing with it changes the trajectory to a collision course? My suspicion is that Perminov was not thinking real clearly, spoke out of turn, or off the cuff when he made the remarks that have been so widely quoted. A person would not have reached the position he's in by advancing such radical proposals in such an unclear manner. That's not to ridicule or derogate him; it is, in fact, to simply pretend I didn't read those quotes. The point is, if we can maintain our civilization for the foreseeable future, it is likely that we will, at some point, need to figure out how to divert an asteroid from impacting the earth. It might even be as soon as 2036 or 2068. The point is, we don't know right now, and each refinement of Apophis' orbit seems to reduce the chance of impact. I just don't believe he was thinking when he made his 2032 remark, and I don't believe we should take the remark seriously. I doubt that he was speaking for the Russian Government, and I doubt the rest of the world would be very happy about allowing such a project to happen without a whole lot of particulars that are simply not available yet.