Joined: Mar. 2013
|Quote (Otangelo @ Nov. 18 2015,13:54)|
|Quote (NoName @ Nov. 18 2015,12:23)|
|Why is abiogenesis impossible?|
There are many reasons. I will post a small list to begin with:
1. In Miller’s experiment he was careful to make sure there was no oxygen present. If oxygen was present, then the amino acids would not form. However, if oxygen was absent from the earth, then there would be no ozone layer, and if there was no ozone layer the ultraviolet radiation would penetrate the atmosphere and would destroy the amino acids as soon as they were formed. So the dilemma can be summed up this way: amino acids would not form in an atmosphere with oxygen and amino acids would be destroyed in an atmosphere without oxygen.
2. The next problem concerns the so-called handedness of the amino acids. Because of the way that carbon atoms join up with other atoms, amino acids exist in two forms—the right-handed form and the left-handed form. Just as your right hand and left hand are identical in all respects except for their handedness, so the two forms of amino acids are identical except for their handedness. In all living systems only left-handed amino acids are found. Yet Miller’s experiment produced a mixture of right-handed and left-handed amino acids in identical proportions. As only the left-handed ones are used in living systems, this mixture is useless for the evolution of living systems.
3. Another major problem for the chemical evolutionist is the origin of the information that is found in living systems. There are various claims about the amount of information that is found in the human genome, but it can be conservatively estimated as being equivalent to a few thousand books, each several hundred pages long. Where did this information come from?
4. If the many instructions that direct an animal’s or plant’s immune system had not been preprogrammed in the organism’s genetic system when it first appeared on earth, the first of thousands of potential infections would have killed the organism. This would have nullified any rare genetic improvements that might have accumulated. In other words, the large amount of genetic information governing the immune system could not have accumulated in a slow, evolutionary sense.a Obviously, for each organism to have survived, all this information must have been there from the beginning.
5.The sugar found in the backbone of both DNA and RNA, ribose, has been particularly problematic, as the most prebiotically plausible chemical reaction schemes have typically yielded only a small amount of ribose mixed with a diverse assortment of other sugar molecules.
6. all the peptide links to form a proptein must be alpha-peptide bonds, not some mix of alpha and epsilon,beta, and gamma bonds
"The first paradox is the tendency of organic matter to devolve and to give tar. If you can avoid that, you can start to try to assemble things that are not tarry, but then you encounter the water problem, which is related to the fact that every interesting bond that you want to make is unstable, thermodynamically, with respect to water. If you can solve that problem, you have the problem of entropy, that any of the building blocks are going to be present in a low concentration; therefore, to assemble a large number of those building blocks, you get a gene-like RNA -- 100 nucleotides long -- that fights entropy. And the fourth problem is that even if you can solve the entropy problem, you have a paradox that RNA enzymes, which are maybe catalytically active, are more likely to be active in the sense that destroys RNA rather than creates RNA."
7.amino acids and sugars combine and destroy each other. In lab experiments the component chemicals are neatly separated from one another. How is this possible in a primitive ocean?
8. Synthesis vs destruction - For chemical bonds to form there needs to be an external source of energy. Unfortunately, the same energy that creates the bonds is much more likely to destroy them. In the famous Miller experiment (1953) that synthesized amino acids, a cold trap is used to selectively isolate the reaction products. Without this, the would be no products. This poses a challenge to simplistic early earth schemes where lightning simply strikes a primitive ocean. Where is the "trap" in such an ocean? Also, the creation of amino acids by a chemist in a laboratory is still much different from forming self-replicating life.
None of those are adequate.
We have life.
We have chemistry and physics.
We have no reason whatsoever to believe that chemistry and physics could not lead to the formation of life.
I note with mild interest that you ignore the example of tobacco mosaic virus.
I note you appear to be unfamiliar with, and likely unaware of, Schrodinger's production of DNA prior to its discovery.
Surely one of the great predictions of evolutionary theory, confirmed and continuing to be useful.
Not a single prediction of 'design "theory"' has such evidentiary backing.
All 'design "theory"' does is whine about alleged problems with the genuine sciences. It produces nothing of itself, it merely casts aspersions. And whine, endlessly.
Your claim was not that abiogenesis was unlikely, your claim was that it was impossible.
The strongest of your, frankly ignorant, objections, can show, at most, that abiogenesis is unlikely.
Your claim, you need to support it. Why is abiogenesis impossible?
Particularly, the challenge you must overcome is to show that there is some aspect of life that violates the laws of chemistry and physics. Until and unless such demonstration is provided, there is little, as in no, warrant, to suppose that chemistry and physics do not suffice.