More Fruit Fly Larvae

A month or so ago I tackled a DpSU about how all the bad things that happen when you so much as think about tampering with the genetic code for the larvae of the fruit fly disproves evolution. Or rather, doesn’t.

white-eyed_drosophila

Today we have another article on fruit flies, which represents a not a-typical last-ditch attempt to explain away yet another evolutionary tour-de-force to the dangerously curious Creationist masses. Jokes aside, the question of who Brian Thomas’ target audience is is a mystery, albeit one for another day. You do get the idea that these guys are really insecure in their faith, or think other people are.

The article is called Do Hairless Fruit Fly Larvae Spell “Evolution”? Basically, we have a study that reverse-engineers the differences in the fruit-fly genome that cause the species Drosophila melanogaster to have hairs on its larvae, but the related species D. sechellia (see here for the family tree) not to. Brian Thomas begins:

Does it matter whether the larvae of one fruit fly species have hairy backs while those of another are smooth? Well, for scientists who believe both species descended from the same ancestor population, it could perhaps be taken as an example of evolution in action. The genetic causes for these particular differences, however, clearly show that no Darwinian processes were involved.

Couple of points here. History shows that the ICR is firmly wedded to Baraminology, the (BS) idea that multiple species are descended from a given pair of animals on the ark. Consequentially, I’d say that Creationists also would believe that “both species descended from the same ancestor population”. Secondly, Brian Thomas recently spectacularly failed to demonstrate that “no evolutionary processes are involved” in antibiotic resistance. I wonder if he’s learnt? He continues:

An international team of biologists has teased out the genetic underpinnings of fruit fly larval hairs. The researchers found that the presence or absence of hairs resulted from “many subtle-effect substitutions in regulatory DNA,” not in genes.1

(where 1 is the study)

For some reason known only to him, Mr Thomas has a habit of pointing out when mutations happen in non-coding portions of the genome, as if when this happens it’s not evolution. I don’t know why – tinkering with the controls seems like it should play as much of a part as changing the recipe to me…

These minor changes were labeled “evolution in action,” but the study results actually show just the opposite. The variations in larvae hairs show at least two genetic features that only make sense if they were purposefully designed creations.

“Just the opposite”? What is the ‘opposite’ of “evolution in action”? I’m wondering at this point if BT is making promises he can’t keep…

Skipping ahead in the article a bit:

First, the researchers found that reducing the production of these tiny hairs only required the subtle alteration of a handful of DNA sequences that were not genes but were regulatory DNA called “enhancers.” They also found that thousands of DNA bases close to the hair-producing genes were exactly the same between the two species. The differences occurred within a 500-base region that they termed the “focal region.”

The researchers referred to these differences as “mutations,” but by definition, mutations are supposed to be randomly introduced genetic errors. Random differences should therefore be distributed randomly in the genome, not concentrated in a “focal region” that experiences DNA alteration rates “4.8 times higher” than nearby DNA sequences.

Once again,1 randomness is not part of the definition of “mutations”. And I would guess that the focal region is not having more mutations in that location, it’s just that more were saved by natural selection (which is not random).

Why are there so many differences in just one region and so few elsewhere? The authors speculated that the focal region “has evolved under positive selection, or relaxed constraints, or both.” It sounds as though they don’t really know. In fact, the study authors admitted that “detecting the action of natural selection on specific non-coding genomic regions remains a major challenge for evolutionary genetics.”1 Perhaps neither explanation is adequate or accurate.

Science, unlike religion, does not claim to have all the answers at the moment. But we’re getting there…

Now for the goodies:

How could natural selection decide, so to speak, to act on one region of a genome when it can only kill off whole individuals if they prove to be “unfit”? And how does nature act at all, since it has no mind?3

Reference three is to an article on the ICR website called Darwin’s Sacred Imposter: How Natural Selection Is Given Credit for Design in Nature, which is interesting in that it never bothers to tell/remind the viewer as to what natural selection actually is, how it works and what it does. This is important as the author, Randy J. Guliuzza2, could do with such a reminder, as he bases his attacks on how you can’t have ‘selection’ without a ‘selector‘ etc. Please note, only creationists really care about that kind of semantics.3 To deal with Natural selection ‘acts’ by the simple fact of nature that the variation between different organisms mean that, all things being equal, the different organisms have a different chance of reproducing and passing on these traits to descendants. No mind is necessary, in the same way that no mind is necessary to guide a river down a valley.

Yes, changes have occurred in fruit fly genomes.

Glad you admit that.

But since they’re all still fruit flies…

Precisely where is the line that must be crossed before Creationists will admit that “evolution has occurred” in a particular case? Quit moving the goalposts!

…and since the changes are non-random and therefore are controlled by intelligent genetic programming…

The changes are only non-random because natural selection is non-random. It does not follow that they are “controlled” by anything intelligent. And this must be what, the third4 time in recent history that Brian Thomas has implied that things that we call ‘evolution’ are in fact caused by programming in the animal itself that make it adapt itself, Larmarck style?

…these changes do not equal “evolution.”

‘Course it does. Evolution = “Decent with modification”. It doesn’t even matter how it’s done – even Larmarck’s theory counts as ‘evolution’. As for whether it is “Darwinian”, as was the original premise, that would depend on your definition. It would nevertheless require and extremely strict – and, dare I say, ‘Creationist’ – definition for it to not be.

Clearly, the facts that only subtle DNA changes are needed to produce relevant body alterations…

I would think that that would help the case for evolution myself.

…that the DNA changes did not occur in the genes (which would have corrupted vital code)…

How are the regulatory areas any less ‘vital’? It was regulatory type stuff (stop signals) that caused all the havoc in the last Fruit Flies DpSU, after all.

…and that the DNA changes occurred in a small and specific region…

Again, the changes themselves were random (until proven otherwise, which would be exceedingly difficult), but the ones that were retained were not randomly so.

…all add up to spell “Creator.”

No, it doesn’t. Not even metaphorically (mixed though it is). End of story.


References: (just experimenting to see how to work this. Anyone know how you’re supposed to do it?)

  1. ^ I said it in the antibiotics post as well
  2. ^ Who we met before as the co-author – with Brian Thomas – of the Dinosaur Soft Tissue Acts and Facts article at the beginning of the week.
  3. ^ Calamities of Nature: July 20, 2011 – Don’t Want to Believe
  4. ^ He also does it in the antibiotic resistance post and an earlier one about Yeast
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One thought on “More Fruit Fly Larvae

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

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