Other Forms of Life (Evolution)

by David Turell , Wednesday, December 10, 2008, 00:50 (5624 days ago) @ dhw

But that is not what the abiogenists are out to prove, since as a statement it is too self-evident to require proof. The emphasis ... but do correct me if I'm wrong ... is on the theory that the elements needed for life (and reproduction) can come together spontaneously, i.e. without any guiding intelligence. - There is more to the argument than that. The Urey/Miller experiment of 60 or so years ago shot an electric spark in a bottle with some inorganic compounds in liquid water and a presumed atmosphere (that was shown wrong later on), and produced some amino acids and other organic compounds that produced a tarry gunk that was somewhat self-destuctive. The amino acids that are needed for life did not appear. No one has tried to repeat this with alternative atmospheres to my knowledge, because the result was such a dead end. - The Murchison meteor is the largest one to arrive on Earth, and is very well studied. Let's make the presumption, which is pretty close to true, that the universe is really uniform in the way the 92 elements are spread out and the mechanics of star formation and explosion are also uniform. All of the parts of the meteor that broke up in the atmosphere weighed about 100 kilo. The meteor came from the asteroid belt and didn't get captured by Jupiter or Saturn as it passed by and got to us. J&S capture most of them. - The Murchison does not carry the proper amino acids necessary for life as we know it, and the ones that are necessary (if I remember, 6 out of 20) are 7% (roughly) more left-handed than right-handed, not 100% left-handed, which is required for manufacture of our kind of life. Based on the Murchison, we don't know where the amino acids required for life came from here on Earth, since we do theorize that meteors and asteroids bombarded Earth early on, and stars exploded to send all the elements, so that early Earth (before life) had whatever inorganic matter and 'some' inappropriate organic matter present when life somehow started. After the bombardment, some organic compound manufacture had to occur on Earth before life could start spontaneously. The necessary left-handed amino acids and right-handed nucleotides (for RNA and perhaps later DNA) had to be present somehow for spontaneity to occur. - And finally, as I have explained before, organic compound manufacture of compounds necessary for life require processes with feedback loops to control the outcomes to get the right results, the right amounts of concentrations, the right shapes since carbon can make strings, loops of various sizes, etc. It is like the chicken and the egg: how do feedback loop controls get started from scratch? Some amino acids happen to bump together and react to join forces? The production of active protein molecules requie alot more than that. - My conclusion: either some very simple organic molecules got together and luckily over 6-700 million years by lots of undirected banging together, made a simple organism to start life, with stupendous odds against that eventuality, or the start of life was directed. Those are the only two possibilites: Take your choice.