Re: Macro- and microevolution [was: Re: Icons of Evolution]

Date: Fri Jun 15 2001 - 15:14:25 EDT

  • Next message: John W Burgeson: "Griffin #8"

    I too would like to see the "micro-" and "macro-" prefixes to "evolution"
    used consistently as well. Still, I suspect that there will always be
    some ambiguity given that there aren't a lot of clear-cut boundaries which
    have been identified for a definite demarkation. Most frequently, I have
    seen "macro-" used to include changes above the level of species. There are
    references, such as noted by Paul, where the "macro-" prefix is used
    to also include variation produced by mechansisms other than "allelic
    substitution"/"micro-evolution". It's very unclear, however, what is meant
    by "above micro- evolutionary mechanisms", although most recently it seems
    that regulatory "programs" are gaining attention. But the distinction
    remains fuzzy in the minds of most people I've talked to.

    I do concur with Allan that among popular creationist literature (which
    is the sub-topic that started this conversation), the macro/micro division
    frequently correlates with "evolutionary changes I don't believe could
    happen" vs. "evolutionary changes I can accept". This is nothing shocking
    or new, and two minutes with the Google search engine easily confirms this.
    And even for a particular author, the application can be quite
    inconsistent. For instance, the human/great ape split often falls into
    the "macroevolutionary"/"questionable" category whereas the variation in
    entire bird, bat or insect groups are accepted as potential micro-
    evolutionary events. Another problem with such creationist uses (as
    opposed to what is proposed in scientific literature) is that it may also
    imply that mechanisms of macroevolutionary events are beyond investigation.
    This makes it hard to formulate a means of evaluating an explanation
    for the existence of and relationships between "macro-evolutionary"
    divisions. Given current understanding, I suppose the strongest case
    could be made for progressive creation via modification of locally
    extant organisms over a long period of Earth's history ("Old-earth,
    unnatural, common descent").

    On a separate note:
    Peter Ruest appears to distinguish macro/micro, in part, in terms of
    information transformation or acquisition. However, I haven't seen much
    of anything in the literature that would allow one to easily divide the
    vertebrates along such lines, let alone primates. Gene numbers, genome
    lengths, gene diversity & etc. have all been considered as metrics but
    few consider them to be anything but rough and somewhat ambiguous
    measures; first-approximations at best.

    Tim Ikeda

    Mail2Web - Check your email from the web at .

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