Saturday, November 27, 2010

Article on Titan's Atmosphere

The other day, I received an email from someone asking questions about a scientific discovery about Titan's atmosphere (a news release about this can be found here). In the discovery, scientists from U Ariz simulated conditions on Titan's atmosphere and found molecules that could be the precursors to life found in the reaction vessel!

What do I think about this discovery, from a Christian perspective? Did God create life, or did life arise naturalistically from non-living material on the early earth?

First of all, I think this discovery (which apparently has not been published yet in a peer-reviewed journal) should draw quite a bit of interest from both the origin of life community and, of course, organizations like RTB. To offer a brief critique of it, let me first start out by saying that the news article, as usual, appears to have grossly over-interpreted the conclusions that can be drawn from this study (as far as I can tell from only reading the scientific abstract, which is all that is currently available). That being said, I want to make the disclaimer that this study appears to be very good science, and I think it's really interesting and hope they do more on it. It's exciting research, and uncovering more about the universe and the conditions that may be necessary for life to form will help uncover the truth, which is always a good thing if you're a Christian.

So, a brief critique. First, note that the scientific results they are looking to publish are the result of a simulation of Titan's atmosphere. They took the small molecule gases that were found in Titan's atmosphere (CO, methane, and nitrogen), loaded them into a specialized chamber, and bombarded them with microwave radiation. What they found aggregated at the bottom of the chamber was a mix of lots of really complex molecules, including the five nucleobases used in DNA and RNA (those are, adenine, guanine, cytosine, and uracil and thymine) and the two simplest amino acids. That alone is amazing! But is that enough (or even close to enough) to lend support to the naturalistic origin of life?

I would say no, for two big, big reasons (and several small reasons).

First, there is either too much oxygen or not enough oxygen. What I mean is this. The article makes a point that there is enough oxygen in the atmosphere (in the from of CO) to promote the formation of the prebiotics, but not too much. You see, if there is too much oxygen in the atmosphere, the prebiotics will become over-oxidized and useless. However, because of the presence of UV radiation, the prebiotics are also destroyed: in the same way UV radiation damages your skin, UV radiation destroys the bonds of prebiotics. The only way to block the UV radiation is by an ozone layer. However, an ozone layer will not form in an oxygen deficient environment. In other words, too much oxygen, you get destruction of prebiotics, and too little oxygen and you get too much UV light, which destroys the prebiotics. The big problem is, there is no middle ground! The amount of oxygen necessary to form an adequate ozone layer far exceeds the level of oxygen where you get too much oxidation! (This is called the UV-oxygen paradox.) And notice that the researchers admit there is UV light in Titan's atmosphere, but in their simulations, they use microwave radiation (instead of UV radiation). I wonder what would have happened if they had used UV radiation in the same way that it is present on Titan's atmosphere?

Second, the article focuses on a few of the exciting molecules they formed, but it says nothing about the "toxic" molecules they also formed. What I mean by toxic is "detrimental to prebiotic chemistry". The goo they scraped off the bottom of the chamber undoubtedly also contained a series of other complex molecules, the presence of which would completely halt the formation of more complex biomolecules, such as proteins or RNA chains. Furthermore, they are still faced with the problem of homochirality (I may discuss this problem more at a future date).

You also have a multitude of other problems, such as a prohibitively small concentration of prebiotics falling into the ocean (if it's not concentrated enough, the prebiotics just won't ever "find" each other to make bonds), an alarmingly fast degradation rate of the prebiotics (most likely far outstripping the production rate from the atmosphere), the unknown mechanism to form bonds between prebiotics in the presence of water (because water inhibits these reactions), and the list goes on. For more about these problems, see where I quoted Dr Robert Shapiro here.