RE: [Fwd: That's about it for mean, Intelligent DesignHypothesis]

From: Joe Dees (
Date: Tue Feb 12 2002 - 08:35:40 GMT

  • Next message: Joe Dees: "RE: RE:"

    Received: by id IAA13573 (8.6.9/5.3[ref] for from; Tue, 12 Feb 2002 08:41:21 GMT
    Date: Tue, 12 Feb 2002 00:35:40 -0800
    Message-Id: <>
    X-Authentication-Warning: www set sender to using -f
    Content-Type: text/plain
    Content-Disposition: inline
    Content-Transfer-Encoding: binary
    X-Mailer: MIME-tools 4.104 (Entity 4.116)
    X-Originating-Ip: []
    From: "Joe Dees" <>
    Subject: RE: [Fwd: That's about it for mean, Intelligent  DesignHypothesis]
    Precedence: bulk

    ('binary' encoding is not supported, stored as-is)

    >Date: Fri, 08 Feb 2002 16:06:03 -0800
    > "Michael M. Butler" <> "" <>Reply-To:
    > has the nifty images.
    >Graphic and image of Artemia=A0
    >Credit: Matthew Ronshaugen, UCSD
    >Biologists at the University of California, San Diego have uncovered the
    >first genetic evidence that explains how large-scale alterations to body
    >plans were accomplished during the early evolution of animals.
    >In an advance online publication February 6 by Nature of a paper scheduled
    >to appear in Nature, the scientists show how mutations in regulatory genes
    >that guide the embryonic development of crustaceans and fruit flies allowed
    >aquatic crustacean-like arthropods, with limbs on every segment of their
    >bodies, to evolve 400 million years ago into a radically different body
    >plan: the terrestrial six-legged insects.
    >The achievement is a landmark in evolutionary biology, not only because it
    >shows how new animal body plans could arise from a simple genetic mutation,
    >but because it effectively answers a major criticism creationists had long
    >leveled against evolution=8Bthe absence of a genetic mechanism that could
    >permit animals to introduce radical new body designs.
    >=B3The problem for a long time has been over this issue of macroevolution,=B2
    >says William McGinnis, a professor in UCSD=B9s Division of Biology who headed
    >the study. =B3How can evolution possibly introduce big changes into an
    >animal=B9s body shape and still generate a living animal? Creationists have
    >argued that any big jump would result in a dead animal that wouldn=B9t be abl=
    >to perpetuate itself. And until now, no one=B9s been able to demonstrate how
    >you could do that at the genetic level with specific instructions in the
    >The UCSD team, which included Matthew Ronshaugen and Nadine McGinnis, showe=
    >in its experiments that this could be accomplished with relatively simple
    >mutations in a class of regulatory genes, known as Hox, that act as master
    >switches by turning on and off other genes during embryonic development.
    >Using laboratory fruit flies and a crustacean known as Artemia, or brine
    >shrimp, the scientists showed how modifications in the Hox gene Ubx=8Bwhich
    >suppresses 100 percent of the limb development in the thoracic region of
    >fruit flies, but only 15 percent in Artemia=8Bwould have allowed the
    >crustacean-like ancestors of Artemia, with limbs on every segment, to lose
    >their hind legs and diverge 400 million years ago into the six-legged
    >=B3This kind of gene is one that turns on and off lots of other genes in orde=
    >to make complex structures,=B2 says Ronshaugen, a graduate student working in
    >William McGinnis=B9 laboratory and the first author of the paper. =B3What we=B9ve
    >done is to show that this change alters the way it turns on and off other
    >genes. That=B9s due to the change in the way the protein produced by this gen=
    >=B3The change in the mutated protein allows it to turn off other genes,=B2 says
    >William McGinnis, who discovered with two other scientists in 1983 that the
    >same Hox genes in fruit flies that control the placement of the head, thora=
    >and abdomen during development are a generalized feature of all animals,
    >including humans. =B3Before the evolution of insects, the Ubx protein didn't
    >turn off genes required for leg formation. And during the early evolution o=
    >insects, this gene and the protein it encoded changed so that they now
    >turned off those genes required to make legs, essentially removing those
    >legs from what would be the abdomen in insects.=B2
    >The UCSD team=B9s demonstration of how a mutation in the Ubx gene and changes
    >in the corresponding Ubx protein can lead to such a major change in body
    >design undercuts a primary argument creationists have used against the
    >theory of evolution in debates and biology textbooks. Their specific
    >objection to the idea of macroevolutionary change in animals is summed up i=
    >a disclaimer that the Oklahoma State Textbook Committee voted in November,
    >1999 to include in that state=B9s biology textbooks:
    >=B3The word evolution may refer to many types of change. Evolution describes
    >changes that occur within a species. (White moths, for example, may evolve
    >into gray moths). This process is microevolution, which can be observed and
    >described as fact. Evolution may also refer to the change of one living
    >thing into another, such as reptiles and birds. This process, called
    >macroevolution, has never been observed and should be considered a theory.=B2
    >=B3The creationists=B9 argument rests in part on the fact that animals have two
    >sets of chromosomes and that in order to get big changes, you=B9d need to
    >mutate the same genes in both sets of chromosomes,=B2 explains McGinnis. =B3It=B9=
    >incredibly unlikely that you would get mutations in the same gene in two
    >chromosomes in a single organism. But in our particular case, the kind of
    >mutation that=B9s in this gene is a so-called dominant mutation, so you only
    >need to mutate one of the chromosomes to get a big change in body plan.=B2
    >The discovery of this general mechanism for producing major leaps in
    >evolutionary change has other implications for scientists. It may provide
    >biologists with insights into the roles of other regulatory genes involved
    >in more evolutionarily recent changes in body designs. In addition, the
    >discovery in the UCSD study, which was financed by the National Institute o=
    >Child Health and Human Development, of how this particular Hox gene
    >regulates limb development also may have an application in improving the
    >understanding human disease and genetic deformities.
    >=B3If you compare this gene to many other related genes, you can see that the=
    >share certain regions in their sequences, which suggests that their functio=
    >might be regulated like this gene,=B2 says Ronshaugen. =B3This may establish
    >how, not only this gene, but relatives of this gene in many, many different
    >organisms actually work. A lot of these genes are involved in the
    >development of cancers and many different genetic abnormalities, such as
    >syndactyly and polydactyly, and they may explain how some of these
    >conditions came to be.=B2=A0
    >Copyright =A92001 Regents of the University of California. All rights
    >Official web page of the University of California, San Diego

    Looking for a book? Want a deal? No problem AddALL! compares book price at 41 online stores.

    This was distributed via the memetics list associated with the
    Journal of Memetics - Evolutionary Models of Information Transmission
    For information about the journal and the list (e.g. unsubscribing)

    This archive was generated by hypermail 2b29 : Tue Feb 12 2002 - 08:56:34 GMT