I came across this passage in another blog, Alcaide’s Cafe, written by Russell Husted. As a general rule, Russell’s page is considerably more sophisticated and better written than most of its kind, but this passage came as a surprise to me. In this post, he discusses the fact that finding water and methane on Mars is not necessarily evidence of life on Mars, and on that point he is of course correct. Those things might provide evidence that microbial life was once present, or is now present, on Mars, but that is still an entirely open question. But he doesn’t stop there. He seems to think that if we do find life on Mars, this will be a problem for evolution because that life, presumably, stayed at the microbial level and did not “advance” to more complex, multicellular life. He writes:
But here is the devilish thought that came to me, as I was thinking about all this. What if we really do find indisputable evidence that life once flourished there? The next question, surely, must be whether it ever "evolved"! Suppose we find that single cell life, perhaps even several types of single-cell organisms, flourished all over Mars, but we also find evidence that it did not evolve or "advance" into anything like what we have here on earth. Suppose it remained forever simple, never dividing into, and including, both plant and animal varieties, or multi-cellular forms, or anything we'd call "complex", or "higher forms"? Suppose that the methane, we've detected, actually is being produced by the natives who are still, after a billion or two years of occupation, no more than bacteria-like or algae-like? If life stayed that simple on Mars, does that not pose a bit of a threat to the theory of evolution? If the evolution paradigm is correct, should not life that "arose" on Mars, and persisted for a billion or two years, perhaps still surviving in hospitable enclaves today, have "evolved" in a pattern at least a bit like the history of life on earth? I think the folks hoping to find life on Mars better be hoping, as well, to find "higher life" if they find any life at all. If they don't, it seems to me the argument that you and I exist all because of the creativity of "evolution" is substantially weakened, and the Genesis (Biblical) explanation looks a lot stronger.
This is false for two primary reasons.
First, he is assuming that the “evolution paradigm” (that’s a teeth-clench phrase) requires that life must proceed along the same paths of life on earth. This is an unwarranted assumption. There is no requirement that life must have evolved beyong single-celled creatures. That life did follow the path from unicellular to multicellular forms on earth is the function of contingent events and there is no reason to assume that those same events would have taken place on Mars as well, or that contingent events that could have stopped that development did not happen on Mars.
Second, the existence of unicellular life for one or two billion years without the formation of multicellular life wouldn’t be a problem on Mars because it obviously was not a problem on Earth. The first single-celled life on earth appeared at least 3.7 billion years ago, but the first multicellular life did not appear until some 2 billion years later. Since unicellular life, and only unicellular life, existed on earth for that long, it would hardly be difficult to believe the same thing happened on Mars, if that indeed turns out to be the case.