Here is some information on the
Urey-Miller experiment written explicitly as a reply to
Icons.
You're right that there are too many to discuss them all at once so how's about we start with the Urey Miller experiment.
First of all, you have to understand the purpose of the experiment. The purpose of the experiment was to determine whether or not relatively complex organic compounds could form under relatively simple conditions, focusing on the conditions that existed early in Earth's history. One argument against abiogenesis was that complex organic molecules can't form under natural conditions; they can only be formed by already existing life, or under artificial conditions. So the Urey-Miller experiment was meant to see what conditions the formation of organic molecules requires.
And the Urey-Miller experiment was a great success! Under very simple conditions, complex organic molecules like amino acids could form.
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It was later found by geochemists that the mixture used was not what was indicated to be available in the early rocks so new experiments were done for a more realistic simulation. No amino acids were formed under these conditions.
This is false. The experiment was replicated under a wide variety of different conditions reflecting possible conditions of the early Earth, and in each of them amino acids and other organic molecules formed. In some cases the amounts produced were less than in the Urey-Miller experiment, but they were there.
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The problem with this 'icon' is that despite the fact that it is now generally agreed that oxygen was present in the early atmosphere....
This in not generally agreed to at all. At least it wasn't present in amounts that would have a significant effect on the early organic chemistry. The presence or absence of oxygen would be indicated by the chemical traces in early sediments; the evidence that there was no oxygen is overwhelming and clear.
Speaking personally, I find few things more awesome than contemplating this vast and majestic process of evolution, the ebb and flow of successive biotas through geological time. Creationists and others who cannot for ideological or religious reasons accept the fact of evolution miss out a great deal, and are left with a claustrophobic little universe in which nothing happens and nothing changes.
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M. Alan Kazlev
™ Version 4.2
