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If evolution is merely leading to greater survival of the fittest, it could have stopped with sharks or with a shark that can defend against the few natural enemies a shark posseses. Instead, relatively fragile human beings are sitting around debating on the Internet - and still being eaten by sharks.

First of all, humans have not evolved from fish. You seem to picture the tree of life as a sort of ladder with humans on the top, sharks farther down, et cetera down to bacteria. It is nothing of the kind.

Anyway, the evolution of complex organisms is a fine example of what is called a 'random walk.' Think about it: the initial life forms were necessarily simple and could not evolve to be simpler. But a subset could evolve to be more complex, so it did. With time there arose niches for more complex forms that were not there initially. For instance, certain unicellular organisms (prokaryotes) would band together into multicellular ones (eukaryotes), trading off independent reproduction for other benefits. In brief, the scope of complexity started out at rock bottom and could only increase by random changes as time went one.

As an analogy, think of companies. The first businesses to arise in a world would probably be one person efforts. In time it might be profitable for some such businesses to fuse and expand. Eventually you would observe a great range of company scales from one to many thousand employees, with the distribution skewed heavily toward the former. Noone would suggest that this development required a grand plan to come about. The increase in complexity happened because it could happen, whereas a decrease in complexity could not.

Let's see, we start with the simple and it can't get any simpler so it gets complex. Why? How about it dies, it doesn't reproduce, it doesn't become more complex, it never does a damn thing. Why not? It trades off single cell self reproduction for complexity and sexual reproduction? Come again?

Nature does not tend toward the complex. All nature is supposedly winding down through entropy to a state of nothing happening in the end. So why does nature bother to create life, which becomes more complex, which becomes conscious, which turns and contemplates nature? According to a purely mechanistic view this is all a bit of a random practical joke, because we are sitting around like foolish little machines and turning the illusion of our intelligence to meaningless questions such as "God" and "evolution." maybe it is all a meanigless random set of events, but there is more mystery to be discovered and for some reason we seem to be very interested in those mysteries. I think there's a reason, one we can't or certainly haven't approached.

I think your description of life and complexity was perfectly logical.

For instance, certain unicellular organisms (prokaryotes) would band together into multicellular ones (eukaryotes), trading off independent reproduction for other benefits. ....

OK, I'll bite.

How did these certain unicellular organisms band together into multicellular ones?

I'm confessing my ignorance of this phenomenon, both in existence and mechanism.

I have this mental image of the one-celled organisms floating around, presumably at some optimal spacing to allow the concentration of nutrients about each to remain above depletion, and the concentration of waste products to remain below deleterious levels.

And then what? I'm working on a mutation to explain the "decision" to band together, and coming up blank. They are single-celled, so there is no much room for a brain and decision making, thus the quotes.

OK. Let's try a hypothetical mutation. One of the organisms exhibits a mutation resulting in a sticky secretion on it's outer surface. Now a random current comes along, and it bumps into its neighbor. Two random events, both must occur within the lifespan of the organism. So now it is stuck to its neighbor who does not have the mutation - I can only fly so far into the face of probabilities. This has to give the pair some advantage over the individual organisms. The advantage should exceed the disadvantage of competing for the same nutients and waste removal.

So - where does this lead? Feel free to correct my premises and assumptions. I didn't want to give the impression of being closed minded, so I did my best to jump start the thought experiment.