Posted on 12/01/2003 5:20:42 AM PST by neverdem
ifty years before Darwin defended his theory of evolution in ''The Origin of Species,'' the French biologist Jean Baptiste Lamarck put forward a theory of his own. For Lamarck, life has an inherent tendency to develop from simple to complex through a preordained sequence of stages. The lineage to which human beings belong is the oldest, since we are the most complex of living things. Present-day worms belong to a lineage that is much younger, since they are simpler. For Lamarck, today's human beings and worms do not have a common ancestor, even though human beings derive from wormlike ancestors.
Darwin's theory was radically different. All the organisms alive today trace back to a common ancestor. And Darwin found no merit in the vague idea that lineages have an ''inherent tendency'' to develop through a set sequence of stages. Rather, he proposed a concrete mechanism -- natural selection -- to explain why lineages change through time and why they diverge as each responds to different environments. No wonder he was irritated when some of his contemporaries dismissed his theory as a mere restatement of Lamarckism.
Darwin's successors further advanced the idea that evolution has no pre-established sequence of stages. Lineages evolve in response to accidental circumstances. Where Lamarck's theory sees the history of life as the unfolding of an inevitable pattern, Darwinism gives pride of place to contingency. In ''Wonderful Life,'' Stephen Jay Gould provided a vivid metaphor for this thought, drawn from the 1946 movie in which the character played by Jimmy Stewart gets to see that his world would have been profoundly different if he had not existed. Gould contended that life would have been profoundly different if conditions at the start of the evolutionary process and along the way were only modestly different. Human beings, and the features we have that we most prize, are radically contingent. Replay the tape and there would be no human beings, and nothing remotely like human intelligence and language. Indeed, there would be no mammals and no vertebrates.
Simon Conway Morris's bold new book, ''Life's Solution,'' challenges this Darwinian orthodoxy by extending ideas he presented in his ''Crucible of Creation.'' He is a booster of inevitability. Replay the tape, he says, and the same broad patterns will emerge. He is also an emphatic adaptationist; he insists on the ubiquity and power of natural selection as a determinant of evolutionary outcomes. Lamarckism is a dirty word in present-day biology, so it is no surprise that Conway Morris does not choose to describe his theory as Lamarckian. But there is an additional reason the L-word goes unspoken in his book. Conway Morris builds his case for the inevitability of numerous evolutionary outcomes mostly on a Darwinian foundation.
His crucial observation is something Darwinians have always known about but, he thinks, have never properly appreciated: the pervasiveness of convergence. When two species are similar because they inherit traits from a common ancestor, the similarity is said to be a ''homology''; when they are similar because their ancestors independently evolved the same novel features, this is convergence. The camera eye found in vertebrates has independently evolved in other groups -- in squid, some marine worms, jellyfish, snails and spiders. In addition to such standard examples of convergence (like the remarkable similarities that unite placental and marsupial mammals), Conway Morris presents scores of fascinating examples that are less familiar. The lesson is clear. The living world is peppered with recurrent themes; it is not an accumulation of unique events.
Conway Morris argues that convergence is a decisive objection to radical contingency. He is right: we should reject the claim that evolution of the camera eye in the vertebrate lineage depended on all the historical circumstances being precisely as they were. The lineage leading to squid was able to accomplish the same result with a different set of starting conditions. However, it is a further step to show that evolution of the camera eye was inevitable (or even highly probable). You can't show that an event was inevitable or highly probable just by pointing out that it has happened many times. To estimate the probability of the camera eye's evolving, you need to know how many times it evolved and how many times it did not. Conway Morris never describes how often convergences failed to occur.
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Even if the probabilities of different evolutionary transitions could be estimated, a second obstacle confronts claims of inevitability. Imagine a long sequence of evolutionary transitions, stretching, as Conway Morris humorously remarks, from the prebiotic soup all the way to shopping. Even if each transition is highly probable, it does not follow that the transition from the first to the last is highly probable. The problem is that probabilities multiply; multiply a big probability like 9999/10000 by itself enough times and you get a probability that is very small indeed.
Toward the end of the book Conway Morris ventures beyond the confines of Darwinian theory. He calls for the development of new biological ideas to explain how life repeatedly manages to discover the tiny islands of adaptedness in a vast ocean of biological possibility. He apparently does not believe that the theory of natural selection suffices. He also makes bitter remarks about the self-congratulatory atheism of many popularizers of evolutionary theory. He thinks the large-scale features of the history of evolution ''are congruent with a Creation,'' though they do not ''prove'' that God exists. He finds it significant that our universe ''seems strangely well suited for us,'' without pausing to consider that a hospitable universe is the only kind we could possibly observe. His recommended ''path to recovery'' from the corrosive naturalism that he deplores involves facing up to the fact that ''it is reasonable to take the claims of theology seriously.'' Lest the reader misunderstand, he repeatedly emphasizes that he has no respect for creationism or for its current repackaging under the heading of ''intelligent design theory.'' He clearly indicates which philosophical and theological ideas he opposes, but he provides few details about the ideas he endorses. The direction of his yearning, however, is plain.
Elliott Sober is a philosopher of science whose most recent book, written with the biologist David Sloan Wilson, is ''Unto Others: The Evolution and Psychology of Unselfish Behavior.''
I agree that it's significant. The Earth could be different. Our poles could be so cold that no human could survive there. The Sahara could be so vast, that Africa would be totally inaccessible. Volcanoes could be more prevalent. In short, there might be only a small section of the globe where humans could survive. Think of gorillas. They don't have a big range. Think of penguins. Pretty confined.
But humans can go anywhere. We did it without advanced technology (think eskimoes and tuaregs)and we dominate the planet wherever we go.
Almost like the place were made for us.
a hospitable universe is the only kind we could possibly observe
So, if the Earth seems perfect for Humans, it proves nothing, says the author. How could it be otherwise?
And
If much of the Earth is imperfect for Humans, it seems to speak against the notion that the place was made for us (Bierce's observation)
I think both sides would like to have it both ways. Well, that's what makes the whole topic so interesting.
The point is: We Don't Know How We Came To Be Here As We Are. To listen to the "learned scientists" who participate so passionately in the evolution debates on this forum, one would think we've got it all figured out. THEY ARE WRONG.
"You see, there's no question whether Post Grape Nuts Cereal is right for you. It's whether you're right for Grape Nuts." -- Wilford Brimley
Quantum physicist have gotten to a point where they say something - a word or a thought - had to start it all. They stop just short of God, because they can't find a way to make him a mathmatical equasion.
(Quantum Questions - Ken Wilber)
"In the beginning was the word, and the word was with God, and the word was God."
(Holy Bible)
And if the Oceans covered 99% percent of the planet, that would make it more hospitable to man?
Probably there are others beside Ambrose Bierce who have no understanding of climatology.
If the present state of affairs is virtually inevitable, that too proves ID.
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