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Sunday, July 1, 2012

Reflections on the Origin of Species

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The The Origin Of Species by Charles Darwin was published 150 years go as I write this. At the time, several different alternative theories of the origin and history of life were being discussed in the West. Some of these theories were theological. Theological ideas included a literal translation of the bible, with the flora, the fauna, and humans created in three separate but related creation events on a freshly made earth just a few thousand years ago. Another theological idea had an Abrahamic God’s hand involved in the history of life but in ways we were not likely to understand until after death. Still another idea, championed by the influential Louis Agassiz, had several God-made origins each representing a different combination of habitat, ecology, climate, and human race. Ice ages would periodically wipe everything out and then God would replace the bits, much like how a gamer re-creates a simulated landscape after system crashes or save failures in SimCity (See Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral for an excellent overview of this and related issues). Maybe the gamer does it a little differently each time, and maybe god did that too. Non theological ideas were emerging at the time as well including some like Darwin’s, but it was Darwin that focused and created several of the key models that are part of Evolutionary Theory today, and it was Darwin and Wallace who advanced the specific theory of Natural Selection. These evolutionary ideas rested within a broader panoply of evolutionary ideas, some of which have faded away, others incorporated, others waiting to be reconsidered.

The Origin of Species was itself a bit like a Noachian flood in that as we look back we often imagine a pre-Origin dark ages of theological misunderstandings washed away by the flood of The Origin which gets it all right. And this is true to some extent from a purely scientific point of view, but in the broader context of the history of good ideas and the still broader context of the history of all ideas (good or bad) it simply isn’t close. Or at least, the world of modern Western ideas is awash in living fossils, to put it nicely.

Theological ideas about the origin and history of life are very much the same today as they were in the mid 19th century. There were and there are young Earthers and there were and there are those who did not care about the Usher young-earth chronology but have God’s hands on the levers of biological creation and history. A careful analysis would probably reveal differences between Paley’s Natural Theology and Behe’s intelligent design but both are Intelligent Design theories and the differences between them … and this is critically important … are not related to which one is more correct. Both way incorrect. They are both irresolvable wrong. Irreducibly wrong maybe. They are both made up, religiously motivated, and politically motivated. They would both ultimately become constructions of anti-science rhetoric more so than they had ever been religious doctrine.
The history of change in scientific theories should be considered much more complex and dynamic. Pre-Darwinian evolution is probably understudied. Darwinian theory consisted of multiple ideas related to each other to varying degrees. “Darwinism” is the idea of common descent, but it is also the idea of Natural Selection. The former is an assertion about what the history of life looks like, the latter a mechanism for change. “Darwinism” is a theory about branching, or speciation, of life forms, something that we probably take more for granted today than in an age where the prevailing culture was linked to a theology in which all species were made within a few days time as we see them today, more or less. I recommend Ernst Mayr’s short book One Long Argument: Charles Darwin and the Genesis of Modern Evolutionary Thought (Questions of Science) for a quick read on the complexity of Darwin’s theories.
Meanwhile, other aspects of the science related to evolution subsequent to the Origin have been very dynamic. The mechanism of inheritance and the role of mutation and population genetics were only vaguely, and in many details incorrectly, understood by Darwin and his contemporaries. I find it interesting that starting some time in perhaps the 1970s or a bit later, many people including geneticists but also various science writers and others have attributed to our understanding of DNA a much greater power than it has earned. Even before DNA was figured out, this was true. The “Synthesis” was all about imbuing Darwinian Theory with newly understood genetics and some cool math to finish off the central theories of life and evolution, and thus understand everything (I oversimplify but not much). But there was a lot more to know, it turned out. With the realization that the DNA molecule is the place where inherited information is stored, and that it is a double helix, and so on, we could now aspire to understand life at the most basic level and in all its details and expressions. Well, it’s been a few decades and we are still discovering new and important things about how DNA works, and the connection between complex ecology, evolutionary histories, and behavior on one hand and DNA on the other is a gap that grows wider, not narrower. The Human Genome was going to advance our understanding of human biology including development, disease, mechanism, all of it. But the day after the sequence was published we did not know a lot more than before.
Granted, I’m characterizing and lampooning a public view of science more than what scientists actually thought. But not really. Geneticists will not want to hear this, but they have long associated their work with words like “truth” and the work of morphlogists or other scientists with terms like “conjecture” and “indirect evidence” and have had a hard time dealing with he fact that truth comes along with a lot of … conjecture and uncertainty, rethinking after some “conjectural” field disproves your overly neat theory, and so on.
But that is a bit of a digression. My main point is that despite the shortcomings of the egos of those involved in the cognate set of genetics related fields of research, the process of understanding the mechanisms of inheritance has expanded and changed the Darwinian body of theories and continues to do so in ways that no theological revelation or understanding has affected any of the religious ideas about the origin and history of life. Biogeography, ecology, the investigations of the deep sea, experimental work on the origin of life, and of course behavioral biology are also major players in reshaping Darwinian Theory.
Very little of Darwin has been thrown out. Less Darwin has been thrown out than Newton, considering that everything Newton did with mechanics is a tiny bit wrong. (Yes, I know, that is an absurd comparison on most levels, but still interesting to think about.) Most of what has become known since The Origin has related to, been informed by, modified but not destroyed, and built on that which is in The Origin.
Key Words: A.R.Wallace, Agassis, Charles Darwin, evolution

Reflections on the emOrigin of Species/em

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