Friday, January 13, 2006

one thing leads to another

W ripped me a new one the other day about Nature and its scientific merits. As a basic researcher, he's entitled to his peeves about this sort of thing. Back when I was hard-core, I would have never read Nature, just as, to this day, I think it's ridiculous to read Scientific American. But it's foolish to be too stringent about such things. For example, if I had not majored in chemistry, Scientific American might have been the appropriate reading for a casual enthusiast. Similarly, for some of us who are not in the lab running gels, Nature is just the ticket. Its focus is on the frontier, where basic science meets relevance. That is a very thought-provoking area, even though it is exactly that focus that causes some to dislike the magazine.

I suppose I am getting defensive about this because I just read the latest issue and found two articles fascinating. The first is part of continuing meditations about how life originated- more specifically, how DNA came into existence. There is, apparently, general acceptance amongst evolutionists that DNA is a descendant of RNA. This, in and of itself, is a big bit of information to digest for me, considering that, in current living systems, DNA is considered the central, essential component, whereas RNA is considered DNA's, well, b*tch, in many ways.

But, how did DNA evolve from RNA, and why? DNA is quite uptight; it pairs up just so and tends to be found as a double-helix. RNA is much more free form. It is normally a single strand and can assume many structures. If we accept that the world is always tending to entropy, then freedom would reign supreme, and RNA should be preferred. So, how did the shift occur? Well, a paper in Biochemie suggests that viruses may have played a critical role in evolution.

All viruses have their own genetic information, one of the reasons that viruses really challenge the notion of what is alive and what is not. But, while all living cells now employ DNA to store genetic information, viruses come in flavors- some RNA, some DNA. The research paper in Biochemie advances the idea that cells started out with only RNA and no DNA. Then, the evolution of viruses resulted in DNA viruses that infected RNA-cells. This DNA infection is what triggered the evolution of cells to permanently adopt and depend upon DNA.

The second article is connected in some ways. Just like a minor viral infection may have had a major impact on the evolution of cells, a controversial paper in Nature claims that the downstream effects of global warming can already be seen in alarming ways in nature. Take, for example, this poor guy:

This is a Panamanian golden frog, among many harlequin frogs which are dying out. The death and near extinction of these harlequin frogs are linked to a rise in the transmission of a pathogen which affects frogs. And this increased pathogen transmission is tied to changes to the climate. Climatologists are at odds about how definitive these data are, but it certainly seems like cause for concern to me. The idea that these small changes to the climate are not actually small in terms of the impact of the overall health of living beings makes you realize how precious and delicate the world is.

In other news, I learned how to use evite today. Yes, today, for the first time. And yes, I am pathetic.

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