Most people think of "Darwinism" as equivalent to "evolution" but that can't be right. There are some mechanisms of evolutionary change—like random genetic drift—that clearly don't fall under the general beliefs of Darwin and his modern followers.
In today's terminology, Darwinism refers to a worldview that emphasizes natural selection as the most important mechanism of evolutionary change. Some extreme Darwinists even deny that change by random genetic drift counts as evolution.
Those of us who adhere to a broader view of evolution are called "pluralists" because we we consider several different mechanisms of evolution and several different levels of evolutionary change.
Jim Lennox is a philosopher. He has written a revised version of the "Darwinism" entry in Stanford Encyclopedia of Philosophy [Darwinism]. Now we all know that philosophers can be wordy, if it can be said by a normal person in two paragraphs then a philosopher can't possible write anything less than a small book. However, at the very least you expect to see a conclusion that makes sense. Is "Darwinism" a viable position in the 21st century? What does "pluralism" mean?
And wouldn't you expect a serious discussion of adaptationism and how it relates to Darwinism? I would.
Read the entry and see if you can decide whether "Darwinism" is a good synonym for "evolution."
[Hat Tip: John Wilkins]
"When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean - neither more nor less.”
ReplyDelete"There are some mechanisms of evolutionary change—like random genetic drift—that clearly don't fall under the general beliefs of Darwin and his modern followers"
ReplyDeleteThen I'll quote Darwin again:
"I am inclined to suspect that we see, at least in some [cases], variations which are of no service to the species, and which consequently have not been seized on and rendered definite by natural selection.… Variations neither useful nor injurious would not be affected by natural selection, and would be left either a fluctuating element, as perhaps we see in certain polymorphic species, or would ultimately become fixed."
The Origin of Species, 6th ed.
And those Darwin's "modern followers" that doesn't have random genetic drift as a "belief", well, good for them. I hope science is not about beliefs and following charismatic leaders. I see random genetic drift (as well as natural selection, gene flow, mutation, etc.) in lots of scientific works, made by scientists who stand on Darwin's shoulders (like all evolutionary biologists of today).
ElPaleoFreak says,
ReplyDeleteThen I'll quote Darwin again: ...
You can find lots of things by combing trough Darwin's works. Like any good scientist, he recognized the limitations of his theory of natural selection and made sure to point out those objections in "Origins."
However, it's a bit silly to take one or two quotations and try to claim that Darwin thought of random genetic drift as an important mechanism of evolution.
He put much more emphasis on the evolution of acquired characteristics than on the role of random genetic drift.
I wasn't talking about "emphasis" or relative importances. Yo wrote "general beliefs". Darwin did propose a primitive version of genetic drift and talked about it as something he was "inclined to suspect". I'd said -if I liked this way of talking about scientific thinking- that he was confessing a belief.
ReplyDeleteAnd for the acquired characteristics, they and other things prove that Darwin was indeed a "pluralist" -Gould said that, didn't he? So today "pluralists" are "following" Darwin much more than those radical ultraselectionists you are always calling "Darwinists".