Re: the definitions of evolution

From: Howard J. Van Till (
Date: Mon Oct 08 2001 - 12:51:59 EDT

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    As a person who habitually encourages the use of distinctions to improve
    communication, I find potential merit in the distinctions among evolution as
    (1) pattern, (2) process, and (3) mechanism that you recommend.

    Let me see if I have a good hold on how these distinctions would function.

    1. I presume that paleontology would be the chief contributor to the idea of
    evolution as (1) pattern, right?

    2. Where would genetic relationships among extant and recent species fall?
    Would that be counted as evidence that there was a (2) process of evolution
    that occurred, even if details re (3) mechanism are not fully known?

    Howard Van Till

    >From: "Uko Zylstra" <>
    >To: <>
    >Subject: the definitions of evolution
    >Date: Mon, Oct 8, 2001, 8:50 AM

    > The recent exchange over Dick Fisher's book has again raised the question of
    > meaning of evolution and our general lack of precise definitions.
    > I have always found Keith Stewart Thomson's "Marginalia" column in the
    > Scientists (70:529-531, 1982), to be very helpful. Thomson distinguishes three
    > meanings of evolution:
    > Evolution as Pattern (e.g. fish preceded amphibians in fossil record)
    > Evolution as Process (e.g., fish gave rise to amphibians in fossil record)
    > Evolution as mechanism (e.g., natural selection)
    > While there is abundant evidence for evolution as pattern, the evidence which
    > is generally cited in textbooks, etc., there is scant evidence for the actual
    > process of evolution. Furthermore, the recent discussion/debate about
    > irreducible complexity and intelligent design points tot he fact that there is
    > limited evidence for the precise mechanisms that account for the actual
    > that might explain the patterns that we observe. Until we are more consistent
    > what me mean by evolution and more consistent in the explanation of the
    > empirical evidence as to what meaning of evolution it is evidence for, we will
    > continue to have confusion and deep differences in our discussion of
    > "evolution".
    > I, for one, recognize overwhelming evidence for "evolution as pattern" which
    > indicates support for common ancestry. However, I find minimal evidence for
    > actual process which has brought about this pattern ov common ancestry.
    > Speculation in this regard does not contribute to scientific objectivity.
    > Scientific objectivity should lead us to say we don't know, if we don't have
    > empirical evidence for it.
    > Shalom,

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