Keith Devens .com

Entry 1383

Via Slashdot, Still More Evidence for Evolution... huh? Where? "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".

This article is less of an explanation of the actual discovery than an attack against creationists. This pretty much sums up the actual info in this news release: they "showed in ... 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."

The point is that they turn on and off existing genes. One of the points Spetner makes is that these "switches" were designed in the first place, and that genes switching on and off like what they may be talking about actually appears to be non-random. I'll state here that I really want to see this article, because there isn't enough info in this news release really judge their discovery.

Most importantly, however, even if there are regulatory genes controlling which other genes get turned on and off, this really doesn't seem to offer any proof for macro-evolution at all. The point is, "how did these structures get there in the first place?" No one has ever shown that new structures, not just those that are "turned on" by a gene being switched, have been formed by mutation. Furthermore, to go on to say that "this is how this stuff happened 400 million years ago" seems to be pretty deep speculation, given the extent of their discovery.

I really like the Oklahoma State Textbook Committee's disclaimer mandated for the state's biology textbooks:

"The 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." - emphasis mine.

Update, PingXao had the same ideas that I had about the article being very "anti-creationist". Quantaman makes well the point I made about these structures getting there in the first place. Finally, this doesn't make any sense. If an animal is to turn from one into another very different animal quickly by "flipping a switch", that other genetic information has to come from somewhere. There would be no reason for all these extra structures to be added to the genome, "silently", waiting to be switched on one day.

Update, my post got a score of zero. Good thing I don't believe in Karma ;-)

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03:03 (utc-5)
edited: 03:27 (utc-5)