Japhia888 said:
If you were to say that going from no life, no organic compounds, to multicellular life as we know it, is extremely improbable. Ludicrous even, and comparable to a chimp, banging away on a typewriter, producing the collected works of William Shakespeare. If you were to say that, you would be entirely right.
All states are equally probable, and equally improbable at the same time, if you are comparing those states to, essentially, a world in which they do not exist. The probablity of going of going from there being nothing, to anything at all, is infinitely small. This is what is really meant when someone says that ever individual state of affairs is a miracle. It is good that you recognize that this kind of statement, alone, is almost meaningless.
From no life to single celled is improbable. From no life to multicellular is impossible. Finally from no life to primate is so improbable that the number for this probability would have to be stashed with all the other probabilities beyond our understanding. It would be put in a sequence which has as it's terminator the probability of the entire universe at one time undefined, and at once becoming defined, and as it is now, with far flung but clustered stars and planets. I would define this probability ("something from nothing"), as being infinitely small, no other event is less likely.[/indent]
It is reasonable to say that life cannot have come about by "chance," because life as we are most familiar with it, is complex. Too much so.
We have found that DNA is the core of all life we have seen, and it is thought that DNA could have come from RNA, which, while less able to store genomic information like DNA, is self replicating and could have also existed, alone, without any real form of life, not even single celled. If anyone thinks that abiogenesis theories are ludicrous because they describe life, single celled, from inorganic, then that is because they are misinformed. Abiogenesis is largely concerned with how those self replicating molecules came about, and them alone. It is a much simpler problem than that of non life to cellular life. Perhaps they came from meteor bombardments, or were created by electrical activity in the atmosphere, discharging into primitive oceans, or perhaps they were created in the super hot vents deep in the ocean. These are the prevailing theories.
As far as the first cells, because their formation of a cell wall, or membrane, holding them together is thought to be crucial in their success, it is also thought that the kind of energy storage molecule which forms that cell wall, called lipids may have existed with or before RNA. We have also seen that lipids will spontaneously form a bilayer, as in hollow shell, but elastic, in the water. This last part is my own conjecture, but it seems to me that at one time there might have been RNA and lipids, and other complex molecules. Remember, this is not even simple life yet, just replicating molecules, and that over a great deal of time, partnerships were formed, lipids interacted and coexisted with RNA, and other types of molecules came together as well, until over all that time, the first single celled organism, composed of several molecular machines working in tandem, appeared.
From that point, life existing, nearly unchanged, single celled and primitive, for 2 billion years, until finally those simple machines came together to make even more complex machines all working together, and on to multicellular life, and onto arthropods, those primitive insects, makes the going from single celled to multi to the ancestors of insects, to reptiles, to birds, to primates, and so on, almost likely.
So, Japhia, is that not a good explanation for our existence? Better than God? A tad more interesting, certainly.
See this timeline on wikipedia for an overview: http://en.wikipedia.org/wiki/Timeline_of_evolution
