Genetic Stop Sign Halts Evolutionary Explanations (DpSU)

Soo… If you genetically modify the good ol’ fruit fly, Drosophila melanogaster, to remove a presumed-redundant genetic ‘stop signal’ at one of the many places in the fly’s genome where there are double ups, you don’t get a very happy fly. Also, this disproves evolution. hmm…

You may have noticed that Mr Thomas has two default templates for his news articles. In the first – such as the baby tyrannosaur news item I covered at the end of this post, or the Io post – he takes a legitimate news piece and/or scientific study, and uses that as a launch pad to talk about something only vaguely related, usually something he claims ‘evolutionists’ cannot yet explain. Alternatively, in a post like this, he takes the study and reinterprets it to back up creationist ideas.

In this article, Thomas also talks about “a study published in 1980, [where] core fruit fly genes were altered, one by one, and the resulting plethora of dead flies proved that there was no “wiggle room” to add the mutations that evolution would require.” The 1980 study can be freely downloaded here, while the new one will require a subscription to Nature (which I don’t have, btw). When referring to the study Thomas links to an article here on the subject, if you want to read along.

The 1980 study deals specifically with mutations that affect “segment number and polarity in Drosophilia“. I would contend that tinkering with such genes is like randomly playing with the foundations of a house that’s already been built. Especially since all the mutations involve the removing of segments. As a general rule, major changes in the body plan of animals are rare, for the reason that other things have been built on top of this and rely on it to work, otherwise they become harmful. You can’t give a cat six legs – at the very least you’ll stuff up it’s finely evolved balance. It shouldn’t be unexpected that such mutations would be largely detrimental – evolution doesn’t progress in such large stages all at once.

As for the new study, this doesn’t really support Mr Thomas’ conclusions either. As I mentioned (to quote from the article on the study) “the majority of genes have more than one stop-signal” which looks at first to be redundant and useless. That we can show that there is a strong reason for this doesn’t mean that the organism cannot evolve. Basically, Thomas does not succeed in backing up his conclusions:

First, in addition to the raw code for proteins carried in the gene, this particular stop sequence is also required for any fruit fly to survive. In other words, the genes plus the regulatory DNA comprise an all-or-nothing system that defies evolutionary ideas of the fruit fly being the product of a gradual accretion of its parts.

Moreira said that both full stop signs are required for “effective regulation of the levels of the resulting proteins.”2 The correct numbers of proteins must be expressed during embryonic development.

Second, this result adds to an ever-growing list of regulatory DNA sequences that do not code for proteins but are nevertheless vital. It appears that a vast majority of any organism’s genome is highly regulated, tightly packed with information (often double-layered), and therefore unable to tolerate many mutations without breaking down.3

Citation 2 is from the alphagalileo.org article I linked to above, while 3 is from one of Thomas’ own articles, which is surprising as it seems to be related to Junk DNA, a common subject in the ID community at the moment, for some reason. There are therefore plenty of better places to cite for this important statement.

In summary, what Thomas is saying is that Fruit Fly genome is such that further modifications cannot be made by evolution as all mutations are detrimental. He is also extending this into the past, effectively claiming that the D. melanogaster genome is Irreducibly Complex. This is again a dangerously large example if IC – there could easily be a simpler form, considering what we know from the two studies. A lot of research has been done on D. melanogaster, and I don’t know if there has been other studies showing places where you can mutate the fly to get surviving offspring. I have a hunch though, that there have been documented cases of this.

So, Thomas is trying to show that “the removal of this one fly “stop sign” demonstrates that the whole fly must also have been purposefully engineered.” He doesn’t manage it. All we have is a study that shows it’s not possible to remove segments from the fly willy-nilly, while the other shows that a common feature of genes is infact useful, as you would expect. More evidence is needed to “prove that there [is] no “wiggle room” to add the mutations that evolution would require”. Until then…

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3 thoughts on “Genetic Stop Sign Halts Evolutionary Explanations (DpSU)

  1. Pingback: More Fruit Fly Larvae « Eye on the ICR

  2. Pingback: Head-Desk Embryological Stupidity « Eye on the ICR

  3. Not only is Thomas’s logic is seriously flawed (since showing that some mutations are lethal or harmful is a far cry from showing that all are); his claims are also contradicted by empirical evidence. There are many known examples of neutral or beneficial mutations in flies and many other groups. I was a biology major in college and often worked with fruit flies. Many mutations in them have been documented, and often the offspring reproduced just fine. Moreover, there is evidence of speciation among fruit flies, other flies, and other groups even in historical times. Google “speciation” for examples. If no beneficial mutations ever occur or get selected for, or as some YECs like to say, “no new information” ever arises, how did we go from at most only 2 alleles for each gene in each animal “kind” only a few thousand years ago (when only a pair of most animals was taken on the Ark) to all the variation we see today, where in many cases genes for various traits include a dozen or more alleles? Not only does that require beneficial mutations and natural selection, but for all that change to happen in only a few thousand years would require more rapid and dramatic evolution than even most “evolutionists” allow. For more discussion of why this is a serious problem for YECism, see: http://paleo.cc/ce/ark-gene.htm

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