On the origins of life

Published on February 29, 2016   47 min

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Other Talks in the Series: Evolutionary Physiology

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DR. BILL MILLER: My name is Dr. Bill Miller, and we're going to talk today about the origins of life. I had been a physician by training and practiced in academic medicine and private practice for many decades, became deeply interested in evolution, which led to my book, "The Microcosm Within - Evolution and Extinction in the Hologenome".
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All of you are undoubtedly familiar with the contentious arguments about Darwinism versus creationism and evolution. This debate has been present within our larger society, and even within academia and outside of it. And this difference of opinion spills over into the concepts of the origin of life, too. The perspective that I'll offer in our discussion about the origin of life on this planet is that it can be considered the result of natural physical processes. No supernatural agency needs to be implicated, certainly. That can remain true even if we do not fully apprehend exactly how life occurred on this planet. This doesn't completely discount the possibility of an intelligent, creative entity of one form or another. But our approach to the topic will be from the perspective and some might say, from the bias that there are intrinsic organic processes that can be actualized on the planet and can propel life on Earth with all its variety of forms and its abundances. That is, if only we can discern those forces. Having said that, the mystery of it all can by no means be entirely discounted.
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And there can be no doubt that the exact origins of life have been a mystery for a very long time. For example, here's what Paul Davies, a brilliant physicist who's championed concepts of self-organization, has to say about it. "Many investigators feel uneasy stating in public that the origin of life is a mystery, even though behind closed doors they admit that they're baffled." Beyond leaving physicists stumped, biologists have an equal sense of wonderment about life and its probabilities. Francis Crick, of Watson and Crick and the DNA helix, says this: "An honest man, armed with all the knowledge available to us now, could only state that in some sense, the origin of life appears at the moment to be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going." Now, we may not be at a point in which we could definitively defend an answer to the question of those exact elements that separate life from non-life, but that doesn't mean we haven't made progress towards reaching an answer. One advantage is that we now have better answers to one part of the puzzle. The question has been this: How is complex life on this planet actually constructed? What we now know is that macroorganisms have to be appraised in a fundamentally different manner than we had before. And by doing that, we're learning that we need to concentrate on their cellular properties as opposed to their macroorganic appearances. We're seduced by the variety, and wonder, and the apparent complexity of life. However, by appraising life as it evolves, improved answers can be offered to its origin, too. The key is to fully and completely appreciate the cellular nature of life on Earth and its eternal partnership with the microbial realm. Lewis Thomas was a great scientist and essayist. And like myself, he trained as a physician. Here's a perspective that I'll quote from his admirable "Lives of a Cell". 'The uniformity of Earth's life, more astounding than its diversity, is accountable by the high probability that we derived originally from a single cell, fertilized in a bolt of lightning as the Earth cooled. It is from the progeny of this parent cell that we take our looks. We still share genes around, and the resemblance of the enzymes of grasses to those of whales is a family resemblance.' Now, whether or not we're formed by a bolt of lightning is not the point. What is relevant is his observation of our unicellular origins and that despite the impressive variety of our external phenotypic appearances, and even the vast majority of the metabolic systems, we're all descended from the unicell and continue to resemble it in remarkable ways. It's this connection that can afford some insights into the origin of life on Earth. So buckle up. We're going to move briskly. There's a lot to cover.