Tuesday, January 27, 2009

A Biochemist Speaks Out:

At the PoliGazette, a biochemist, who identifies herself only as "Claudia" has written a post explaining how evolutionary theory can seem controversial to someone on the outside but is, in fact, not controversial within the biological community. She writes:

But is there a scientific debate with regards to evolution? Yes, there is, but it bears absolutely no resemblance to the one being waged on the ideological front in school boards across the country. The actual debates within evolutionary biology can be roughly divided in two branches: sequential and mechanistic (this is my terminology, not particularly official).

The sequential debates regard phylogenetics, which can be very simply described as how living organisms relate to one another with regards to evolution. Very simply put, it is the debate about our biological family tree; who came from who, whether organism A and organism B share a common anscestor or are similar because of convergent evolution, who came first in the evolutionary tree etc.

The mechanistic debate is a much more fiercely fought one amongst evolutionary biologists, a debate that is not at all aided by its exploitation and mischaracterization by creationists. The debate involves which mechanism or mechanisms are mainly responsible for the evolution of life; whether one mechanism works or not, how well different mechanisms account for recorded events in evolution and whether one mechanism is more dominant than another. The two sides can be (again, very roughly) divided between those who believe that gradual neo-Darwinian evolution is chiefly or solely responsible for the evolution of life and those who believe that gradualist explanations are insufficient and that other mechanisms capable of introducing very fast changes in organisms must be taken into account or even considered dominant.

Both Neil Shubin and Donald Prothero devote sections of their books to this topic and both are highly worth reading. It is, however, dense stuff. The classic model explains the mechanisms of evolution as being selection, genetic drift, gene flow and mutation, which all work in concert to produce new species and alter population gene frequencies. Even reading anyone writing during the heyday of the new synthesis in the 1940s through the 1980s (George Gaylord Simpson, J.B.S. Haldane, Sewall Wright, Ernst Mayr and so on) one can see that there is a huge amount of evidence and theory underlying these basic tenets.

Things have moved along nicely since then with the advent of evo-devo and it is hard to stay current if you don't eat and breathe this stuff.

3 comments:

  1. I am firmly convinced about the reality of evolution. My wife on the other hand is not much interested in it beyond the ramifications of our relationship to our church community, some of which has already been felt. What to tell the kids has been a difficult subject, and was forced on us all of a sudden when my oldest daughter (who always selects science texts about animals, especially dinosaurs) brought home a book on prehistoric life which included int he final chapters drawings of early hominids. My daughter was instantly drawn to that page!

    Anyway, I wasn't in the room when it took place, but overhead the tail end of their discussion where my wife tried to make it as palable as possible but kept qualifying it with "some people think so" and "there isn't very much evidence" and the worst one "its just a theory". I want my daughter to think critically and learn things by examining evidence as opposed to being told, so I don't mind presenting it like it needs to be examined. But why was my wife making it sound like nobody was really sure. Well I got my answer later. When I asked she stated the very first sentence said that evolution of humans was highly debated among scientists. I tried to explain that this meant "how it happened is debated" not "whether it happened" but had a hard time getting through to her.

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  2. Thanks for that personal story, Pete. For us, my wife is convinced that, yes evolution has happened but that its effect on society has been measurable and negative. She thinks that science has walled itself into a corner and cannot think out of the box. I try to assure her that scientific techniques reveal the glory of God but she thinks that I am guilty of compartmentalization. As far as our friends are concerned, I just lay low. Cowardly, I know, but at the moment I am not sure how to address it. Most of our friends are not scientists and view evolution not as a theory to be evaluated but rather as a corrosive influence. The problem is that they do not have the science backgrounds to realize that the YEC arguments are junk. One of my friends came back from the Creation Museum and said "Wow, I learned a lot!" A lot of nonsense is more likely.

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  3. I'm not sure I understand your wife's position, do you mean mankind's realization and teaching of evolution has been negative?

    I'm also totally in the closet, at least around my church friends. I talk about it at work at lot and of course participate online, but otherwise don't advertise. I was open about it to the leadership of my church through my pastor since I myself was in a small leadership role. Eventually we mutually agreed I should step down though it wasn't exclusively about my belief in common descent but that I think that and much other evidence besides calls into question the historical nature of the Bible (obviously Gen 1-11 and to be honest quite a bit farther into those early books).

    My wife grew up in a fundamentalist environment where evolution was evil and the biggest lie, so she lives with a small amount of fear that the secret will come out and we will be judged (though our church here is nothing like the one she grew up in).

    It is a little awkward since our church stresses training up new leaders in order to grow as fast as we possibly can, and I have somewhat ruled myself out of that, and worse, have been moving backward from their perspective.

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