I know most of you have already read it with your print subscription to Seed, but I’ll mention it anyway: my last column can now be read on the web. This one is all about the weird, accidental, clumsy way segmentation patterns in flies are set up.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
Biology consists in multi-dimensional interactions in which little could be designed, but only evolution could adequately deal with the complexity.
What is bizarre about ID is that it takes the complexity and multi-dimensional effects to be evidence for “design,” even though it is just that sort of complexity that resists design, only arising from evolutionary processes. Indeed, genetic algorithms are used where the complexity is very difficult for minds and rational computers to handle.
Glen D
http://tinyurl.com/2kxyc7
A very good column PZ. I must echo Larry Moran’s earlier-expressed concerns about there being little actual science in SEED Magazine (you are probably the most sciencey it gets). I subscribed last year and I’m struggling to decide whether to renew my subscription or not. It just gets so wishy-washy some of the time – why can’t they simply talk about real science more often, like your column does?
In godless books, mindless arguments
We’ve managed to go from “militant” to “ultramilitant” without blowing up a single church!
We’ve managed to go from “militant” to “ultramilitant” without blowing up a single church!
You know, some of you ultramilitant totalitarians have been really slacking in your ultramilitant totalitarianism. Stop smelling the flowers and petting the puppy dogs for crying out loud. No more singing Christmas carols either, please. And no more cookies and ice cream. Thank you.
I can already see the ID quote mines: PZ Myers admits that the genome is like computer code – and computer code requires a programmer!
Yeah, but don’t forget what we’re capable of doing without even lifting a finger. We can corrupt good Christian children by merely teaching them science, we caused the 9-11 disaster via magical and linguistic connections, and we have destroyed science through evolution (UD is trying to save it, because, you know, biology has stagnated while ID research is surging).
Imagine if we really tried to cause evil, considering that our words alone have caused most of the world’s evils. I always consider it a good day’s work whenever I hear of some death or destruction in the world, knowing that I played a significant part in it simply by writing comments on a web log.
Glen D
http://tinyurl.com/2kxyc7
Loved it.
tinyfrog, it seems to me that the point was that it is *not* like computer code. Or at least, not the code of an intelligent programmer. Yes I understand your point that creationists will grasp at any straws to bolster their argument, but still….I think PZ expresses beautifully that what is found in biology is the exact opposite of what you would expect to find in something programmed by an intelligent entity.
Thanks PZ for an excellent article.
“This one is all about the weird, accidental, clumsy way segmentation patterns in flies are set up.”
– Does that mean it looks like they weren’t designed?!!! Duhn Duhn Duhhhnnnn!
robbrown,
He said that the DI would quote-mine it, which they probably will.
Of course, just to play devil’s advocate, PZ: You’re making an assumption that you can’t back up: Namely that the designer would, like us, favour simple, elegant, solutions to problems.
For all we know he could be an obsessive micro-manager that cares nothing for elegance.
Or, so I’d assume the DI will point out when questioned about this. If nothing else, they’re master spin doctors.
This is precisely what we see in the fruit fly. It doesn’t build its segments sequentially at all: instead, gene products interact in complex ways, with broad bands of segmental genes refining themselves rapidly by early interactions to establish a pattern of segmental stripes almost all at once. When the individual segmental genes are examined, they are found to each have stacks of logical switches to turn them on in dedicated patterns in specific places in the animal–each stripe is specified by a hard-coded set of regulatory elements.
PZ,
I’m now convinced that you know the truth.
You’re too smart not to…
The only question still remaining is whether you’re deliberately avoiding admitting it because it will give comfort to creationists, or you’re just too damned stubborn.
So at last the truth comes out: the Intelligent Designer is Microsoft – and Bill Gates is Lord of the Flies!
DI spin: “So regulated development in some creatures is evidence of evolution, but ad hoc development in some other creatures is also evidence for evolution – how convenient!”
Your article contained a germ of an answer to this, that you could predict when the different strategies would be used by examining the speed of development. Evolution predicts that leisurely, patterned development is the base condition, perhaps dating from the time before the evolution of predation. On top of this is layered several different (in different r-selected species) ad hoc patterning systems that accelerate the process.
PZ, I liked the article, but I think the last paragraph made a claim a bit too strong. If human designers had come up with the fruit fly genome directly, we’d justifiably call it a mess of kludges. But if human designers had written the fly genome in a high level language, and a compiler had translated it into the low-level ACGT sequences, then we’d expect it to be almost unreadable. The main argument against design is the fact that the fly genome, as it stands, is something that could have evolved. Out of the many, many possible genomes that would lead to a fruit fly, most are not something that could have evolved from other life forms. That we can see how we got here from there is the proof of evolution. This might be a point a bit too subtle for the article, though.
This is off topic, but I thought you’d like some of the pictures: The Machine Animals of Nantes. Scroll down. Look for squid.
Generation of the repeating stripes of ‘even skipped’ expression certainly shows the ad hoc nature of each pattern element even as the overall repeating pattern looks so orderly.
To add specificity to David vun Kannon’s hypothesis, could you remind us if what happens in short germ band insect.
Background for non-fly people – Drosophila have a long germ band form of embryonic specialization, all the segments and positional identities within segments are initially established essentially simultaneously in a very short time in early embryogenesis. Other insects, superficially at least, have the repeated (both positionally and temporally) specification of segments PZ described. These short germ band insects than have only a single segment being specified at a time, with progression of specification and differentiation moving from one end to another. A number of the genes used in segment establishment and identity (eg. engrailed, Hox cluster genes) are used in short germband insects. So my question to PZ amounts to ‘Do short germband insects have the clean code pattern that his argument predicts?’
I was wondering why you used the word gemish in your article:
“…but if you look under the hood you are simultaneously appalled by the sheer inelegance of the molecular gemisch and impressed with the accumulation of complexity.”
Gemisch (das) meaning, usually in English commixture, mixture, jumble, medley, potpourri, blend and so on, of course. In certain contexts, it could mean sludge, mishash, etc… .
In an event, did you mean to also refer to its sense of Invertzucker ( invert sugar )
and the popular term Gemisch von Trauben- oder Fruchtzucker
( sugar that has undergone chemical changes )?
I’d imagine this would escape most of your readers, but…well, I was simply curious as to why you would use the German word. I must be missing something, no???…and that wouldn’t surpise me, if so! :-))