Meditation 626
Maybe DNA Was From Another Galaxy
by: Dan Shanefield
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A great difficulty with rational belief in "evolution" is that, at the very beginning of life, it is hard to imagine how DNA ever got started. I mean, how did it ever arise, by purely random processes, even in billions of years? That would require that two long strings of complex sugars-plus-phosphates had to line up closely in parallel, and then get connected by a very complex group of amino acids, just exactly right. (And RNA would also have to get initiated, in similar fashion, in order for the whole structure to be self-replicating.)
The problem is that there is absolutely nothing in our natural environment that is part-way there, and which could then have gone the rest of the way by randomly bouncing around, until the exactly right combination was achieved. Even "self-assembly" would not have helped much, if the starting materials which were "part-way there" are never available anywhere on earth.
There seems to be a way out of this dilemma, if we consider the possibility that the right conditions might exist on some other planet, in another solar system, or maybe even in some other galaxy. We know that some of our solar system's planets do have atmospheres heavly loaded with ammonia, carbon dioxide, and other gases. So far-away planets might have the necessary "stew" to form precursors of DNA, even though we never find such "part-way there" materials on earth.
Then a tiny seed of DNA plus RNA might have come here inside a "chondrite" meteorite, or maybe even in the dust inside a cold comet. Billions of galaxies over billions of years might have led to a single asexual seed that could get transported here, when the earth's atmosphere was hot and humid, with the right amount of oxygen for further evolution and eventual growth. This possibility makes it not so hard to believe.