RE: Johnson and "Icons"

From: Hofmann, Jim (jhofmann@exchange.fullerton.edu)
Date: Tue May 15 2001 - 12:25:51 EDT

  • Next message: Moorad Alexanian: "Science and Creationism website:"

    Robert Dehaan wrote:

    "Blaine,

    The issue is not whether the use of drawings, per se, or the simplification

    of them is legitimate. The issue is whether they are accurate. Wells shows

    by use of simplified drawings that Haeckel's simplified drawings are
    inaccurate, and that the biological community has known this for a long time

    and done nothing in concert to correct the situation. Wells goes further
    and
    claims that not only are the drawings inaccurate, but that they are
    deliberate misrepresentations of the facts. "

    It is simply not correct that "the biological community has known this for a
    long time
    and done nothing in concert to correct the situation". The following is from
    Kenneth Miller's website linked to his textbook:

    As you read this, you may wonder why evolution should be limited to changes
    tacked on at the end of the process of development. So did evolutionary
    biologists, and Haeckel's idea was quickly discarded. In fact, evolution can
    affect all phases of development, removing developmental steps as well as
    adding them, and therefore embryology is not a strict replay of ancestry.
    Nonetheless, many of the stages that embryos pass through can indeed be
    understood as remnants of their evolutionary past. One example is the fact
    that the embryos of all placental mammals (including humans) form a yolk sac
    during their development. Why is this important? Because the eggs of these
    organisms do not have large amounts of stored yolk, and therefore their yolk
    sacs are empty! Nonetheless, the persistence of a yolk sac stage makes
    perfect sense when one considers that these animals are descended from
    egg-laying reptiles in which the sac encloses a massive amount of yolk to
    support embryonic development.

                This idea has been pushed back into the news recently by the
    news that Haeckel's drawings of
                embryonic similarities were not correct. British embryologist
    Michael Richardson and his colleages
                published an important paper in the August 1997 issue of Anatomy
    & Embryology showing that
                Haeckel had fudged his drawings to make the early stages of
    embryos appear more alike than they
                actually are! As it turns out, Haeckel's contemporaries had
    spotted the fraud during his lifetime, and got
                him to admit it. However, his drawings nonetheless became the
    source material for diagrams of
                comparative embryology in nearly every biology textbook,
    including ours!

    So, what have we done? Well, we fixed it. Joe Levine and I have now revised
    the drawings that appear on these pages of our textbooks, and the 5th
    Edition of the Elephant book has been published with an accurate drawing of
    the embryos made from detailed photomicrographs. We have also rewritten page
    283 of the 5th edition to better reflect the scientific evidence regarding
    the similarities of early development:

     <<New-embryo-figure.gif>>

    The revised Figure 13-16, showing accurate representations of vertebrate
    embryos, Page 283 During certain embryological stages, vastly
    different organisms show similarities. During later stages of development,
              however, profound changes occur. Thus the adults bear little
    resemblance to one another.

    You can find Miller's comments at:

    http://BioCrs.biomed.brown.edu/Elephant%20stuff/Chapters/Ch%2013/Haeckel/Hae
    ckel.htm

    Jim Hofmann
    Philosophy Department and Liberal Studies Program
    California State University Fullerton
    http://nsmserver2.fullerton.edu/departments/chemistry/evolution_creation/web


    New-embryo-figure.gif

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