Water everywhere

Lately I've been reading about water. How did all our water get to earth. There is a lot of it here. It makes up 0.4% of the earth by volume, about 326 000 000 000 000 000 000 gallons. That's a lot of water. For most evolutionary theories to work, water had to be present in large quantities early on in the earth's development. The problem is that the early earth was hot and dry, molten lava cooling slowly. Also, the early earth had no atmosphere and the solar winds were strong so any formation of water vapour would have been whisked away into space. Hydrogen and oxygen should have been present so the capability to make water was there. The problem that I see is that water needed to have formed fairly quickly in the geological clock, in around 150 million years according to most theories. If it took significantly longer, there would not have been time for the long, slow evolutionary process to occur. To get 326 000 000 000 000 000 000 gallons of water the earth would have had to receive 16 500 tons of water every minute for 150 million years. And that is not considering the water we lose to space by the disassociation of oxygen and hydrogen that is taking place on a tiny but constant basis. There are two main theories on how our water got here. It may have been formed from volitiles in the earth's crust being expelled by volcanoes outgassing or the water may have been imported here by falling comets. Neither of these seem reasonable to me. I can understand the physics of this happening but I can't imagine how either of these could have supplied anywhere close to the amount of water that we are talking about. The articles I have read don't supply any reassurance. There doesn't seem to be a logical physical explanation for it.

The Minimum Requirements for Life

One assignment I received during a graduate course in microbiology was to find a candidate for the first living cell. The first cell would have needed to metabolize and replicate. We (the other graduate students and I) began by looking for the simplest possible living cell. We narrowed it down to the archaeon and viruses. Simple viruses only need about 10 000 base pairs but we disqualified them because they absolutely must have another cell to be able to reproduce. Some archaeon need only 30 000 base pairs in their DNA molecule and so the archaeon became our candidate for the simplest life form and possibly a relative of the first living cell on earth. The largest human DNA molecule by contrast has 220 million base pairs. Then we gathered a list of everything the cell needed to be able to be considered a living thing. Now, I'm going from memory here so forgive me if I omit something or get numbers wrong. Here is what the simplest living things needs to be a living thing;

- a minimum of 30 000 base pairs in the correct order with phosphate and sugars to provide the backbone

- a minimum of 12 proteins with the amino acids in the correct order

- a number of molecules of ATP

- a number of molecules of NADPH

- a semi-permeable cell wall that completely engulfs these substances

There were other things on the list but I forget them. If any one of these components was missing or a tiny percentage of the nucleotides or amino acids are out of order, the cell would not be able to function and there would be no life. It was astounding to me how complex the simplest living cell was. I cannot imagine this set of circumstances happening by chance. First of all, where did all these components come from? The experiment of Miller and Urey in 1953 has been more or less discarded as a viable example of the early earth's environment. Even if there were amino acids, what is the probability of them lining up in the correct order for not one but 12 different proteins. It's been a while since I've taken statistics but the probability of the amino acids of just one protein lining up in the correct order is so infinitesimally small, it is hardly worth considering, let alone a DNA molecule of 30 000 base pairs. It is not logical for the first cell to have happened by chance. There must be another explanation. I have read of a theory that postulates that the components for the first cell were "seeded" on earth by meteorites. I find this unlikely also. What is the probability of all these components being in close enough proximity to each other and then engulfed by a semi-permeable cell wall? What kind of environment could have formed these components somewhere out in space? How could these components have remained viable in the harsh environment of space and the traumatic trip to earth? I have yet to see a reasonable model for the first living cell. This aspect of the origin of life debate pulls me toward the intelligent design side.