Saturday, December 13, 2008

The Origin of Life - Harder than I thought

Hi Everyone,

I have recently been looking into abiogenesis a little more and I have come to realize that it is a much bigger problem than I originally realized. You see, previously I had thought that the origin of life was, for the most part, solved and that only a few little gaps remained in our knowledge. Sadly, it is simply not that way. Here are some of the greater problems:

1. The formation of Ribose. This is the "backbone" of RNA, and researchers have not yet managed to find a way to synthesize it under plausibly prebiotic conditions. Some scientists think that another nucleic acid, such as PNA, came first, but to my knowledge no one knows if a strand of PNA could replicate itself or not.

2. This information was provided to me by Alex over at "The Daily Transcript":

To be able to generate an RNA polymer, you either need the monomers in a "high energy state" or another source of energy. Since RNA polymerase uses NTPs (Nucleotide Triphosphates, or 'active monomers'), the energy that drives the polymerase reaction is derived from the hydrolysis of the extra two phosphates from each monomer. It would be very hard to imagine how such a high energy molecule could be created from non-biotic processes.

3. The protocells created by Dr. Jack Szostak, contrary to the claims of CDK's video on the origin of life, do not qualify as primitive life (CDK states in his followup video, about the origin of the genetic code, that it has been "proven" that life can arise spontaneously by Szostak's experiments). I emailed Dr. Jack Szostak and here is what he wrote in response to my email, asking him if his protocells qualified as life:

Dear Ryan,
The systems we have put together are not yet 'alive', because they cannot replicate their genetic material, and therefore cannot inherit information and evolve. Even we if incorporated a useful ribozyme, for example, it couldn't be passed on to future generations, because we don't yet have an efficient system for RNA replication. This is one of the main things we are working on.

So, as you can see, we are still a ways away from fully grasping the origin of life.

However, this does not mean we should give up: Many other problems for the origin of life, some far worse than this, were solved years ago. For example, DNA cannot form without proteins, but proteins cannot form without DNA. This seemed like an insurmountable problem just a few decades ago, and yet now we know that RNA disposes of this problem. We simply need to avoid having our curiosity satisfied prematurely about life's origins.

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