New paper sets out the precise “Swiss clock” mechanism of embryo development

_{Denyse O'Leary

October 14, 2011

Biomimicry, Evolution, Intelligent Design, News}

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In “From Blue Whales to Earthworms, a Common Mechanism Gives Shape to Living Beings” (ScienceDaily, (Oct. 13, 2011), we learn how the embryo gets organized, hourby hour, in two days:

Very specific genes, known as “Hox,” are involved in this process. Responsible for the formation of limbs and the spinal column, they have a remarkable characteristic. “Hox genes are situated one exactly after the other on the DNA strand, in four groups. First the neck, then the thorax, then the lumbar, and so on,” explains Duboule. “This unique arrangement inevitably had to play a role.”

The process is astonishingly simple. In the embryo’s first moments, the Hox genes are dormant, packaged like a spool of wound yarn on the DNA. When the time is right, the strand begins to unwind. When the embryo begins to form the upper levels, the genes encoding the formation of cervical vertebrae come off the spool and become activated. Then it is the thoracic vertebrae’s turn, and so on down to the tailbone. The DNA strand acts a bit like an old-fashioned computer punchcard, delivering specific instructions as it progressively goes through the machine.

“A new gene comes out of the spool every ninety minutes, which corresponds to the time needed for a new layer of the embryo to be built,” explains Duboule. “It takes two days for the strand to completely unwind; this is the same time that’s needed for all the layers of the embryo to be completed.”

This system is the first “mechanical” clock ever discovered in genetics. And it explains why the system is so remarkably precise.

And just think, it all happened by natural selection acting on random mutations, … Well, let’s just say it would be illegal to introduce, in American or British schools, any kind of doubt that that’s the origin of the mechanism.

Also:

The Hox clock is a demonstration of the extraordinary complexity of evolution. One notable property of the mechanism is its extreme stability, explains Duboule. “Circadian or menstrual clocks involve complex chemistry. They can thus adapt to changing contexts, but in a general sense are fairly imprecise. The mechanism that we have discovered must be infinitely more stable and precise. Even the smallest change would end up leading to the emergence of a new species.”

Ah yes, there’s the ritual kowtow to Darwin (“who changed everything, greater than Copernicus” – E.O. Wilson), although in this case, the PR writers daren’t be explicit.

In reality, “Even the smallest change would end up leading to the … ” death of the embryo.

The real lesson here is the importance of model. Embryo development must be precise, like a clock, and not randomly mutated due to the chances of chemistry.

Comments

Kellyhomes:
PaV:And, of course, we all know that computers arose through blind processes. KH:You could say the same thing about nuclear reactors!
Now, you seem new to this blogsite. So I'll show a little bit of patience for right now. But, I can be a little thin-skinned. So, be aware. Nuclear reaction take place within the earth and, presumably, in earth's core; nuclear reactors are designed. If you can't see this distinction, well . . . .
Provide an alternative then! I’ve been asking KF some detail on his version of ID where the designer needs to intervene millions of times over millions of years. But he’s unable to provide any detail other then that the “signs point to design” and he indicates he will not discuss it further. Conveniently.
It's hard to know exactly where and, therefore, when, these interventions have taken place. But "reason", not religious faith, tells us that causes cause effects. And though matter and energy can be transformed, neither mass/matter, nor energy, can be either created or destroyed. It's just there. So, that which exists---and this includes you---at one time didn't exist. Or would you like to claim that you've existed for all time? So, what power is there that can bring things into existence? And what is this first cause? Well, reason---that is, the Greek philosophers who lived before the time of Christ, and who were not Jewish---tells us that this power must be reserved to God. In the case of the Greeks, it was sort of parceled out to several gods. But there was Aristotle's DemiUrge, etc. So reason, not faith, tells us that some kind of God exists. This is why religions exist the world over; because human reason, where ever it is found, can arrive at these conclusions. For a God who created the entire universe and all it contains, intervening "millions of times over millions of years" is really a simple matter. Now this is the simplest and most reasonable assumption. But, if we want to humor those unable to think things through, we can permit other possibilities: like periodic "seeding" from aliens, and so forth. Just try to think about this. Don't start with preconceived ideas---like materialism, or atheism. It's really not that hard. Naturally, at some level, nature operates to bring about diversity. This will necessarily be limited, but can produce spectacular changes. Where intervention of intelligent agency is required, and where natural forces can take over, will likely be difficult to unravel. But, after all, that's what science is all about.
If it was a computer they would say so. It is not. It looks and in the main acts nothing like a computer.
Is a robot a human? No. But it can act just like a human. Now, is the robot the product of blind forces? Just try and think your way through these things.
But despite literally millions of examples of claimed ID intervention we still don’t know anything about how those interventions come to be. Not a *single* thing!
I've already run out of patience. So, . . . . In your great silliness, can you please tell me exactly how these body-plans arose using Darwinian principles? I await your detailed response. PaV

PS: And a digital, symbolic sequence is precisely what is being announced by Sci Daily, hence their repeated references to paradigmatic examples of computing. This is instantiation, not mere analogy (which last BTW is actually foundational to a lot of scientific reasoning, i.e. it is embedded deeply in how induction works). kairosfocus

KH: Pardon, it is a basic academic courtesy to link to the justification for a claim, rather than giving a dismissive strawman summary. I suggest you start here on and here at IOSE to see why I raise the issue that body plans show strong, empirically tested and found to be reliable signs of design; which should be understood in the context that scientific arguments, being inductive, are inherently provisional though they may be quite empirically reliable, as this one is. If you think the signs are not reliable, do us the favour of showing us why, at minimum by providing links and helpful clips. And, BTW, an algorithm is a finite, step by step sequence of actions that per prescribed process, solves a problem or achieves an end. In the case of a digital, symbolic sequence to specify the steps, we are dealing with algorithms written in language and based on coding and digital communication schemes, all of which are highly irreducibly complex and empirically reliably known to be artifacts of design where we do directly observe the cause. GEM of TKI kairosfocus

"Introduce doubt but surely it has to be reasonable? What’s the alternative explanation you’d like to introduce?" You in favour of being honest with the children then? An hones statement would read: "The development of an organism works like a vastly complex computer programme that is far, far more complex than anything devised by human intelligence. While this developmental programme bears many of the hallmarks of intelligently designed systems, no Darwinian explanation for it's origin currently exists. Beyond the appearance of design, nobody knows how such systems came to be." Any harm in just telling the kids the truth? Alan

Well,
Well, let’s just say it would be illegal to introduce, in American or British schools, any kind of doubt that that’s the origin of the mechanism.
Introduce doubt but surely it has to be reasonable? What's the alternative explanation you'd like to introduce? As we're talking about a specific mechanism you'd need a specific alternative, not some generic "design" coverall that could equally be applied to birds, bees, candlestick makers etc. Can you provide such a ID explanation of the precise “Swiss clock” mechanism of embryo development? Can anyone? PaV
Are we to believe that the “watch” came into existence through blind processes?
Provide an alternative then! I've been asking KF some detail on his version of ID where the designer needs to intervene millions of times over millions of years. But he's unable to provide any detail other then that the "signs point to design" and he indicates he will not discuss it further. Conveniently.
And, of course, we all know that computers arose through blind processes.
You could say the same thing about nuclear reactors!
Gee, cellular processes are just like what computers do.
Did you notice the modifiers in the very sentence you quoted?
The DNA strand acts a bit like an old-fashioned computer punchcard, delivering specific instructions as it progressively goes through the machine.
If it was a computer they would say so. It is not. It looks and in the main acts nothing like a computer. It's poor evidence for ID that X acts a bit like like a computer, computers were designed therefore X is designed. If that's the case it leads me quickly to the conclusion that humans designed themselves! So we come back to the very question you asked PaV:
Put another way, if exquisite precision is needed for proper embryonic development, then where did this precision come from?
Where did it come from? All KF can tell me is that the signs reliably point to design as an origin of all that exquisite precision. But beyond that, who knows. Perhaps you can change that, where *did* it all come from PaV? When, where, how, who or what? Take your pick, any one of them would be more then I know now. KF insists that every new bodyplan observed in the fossil record was the act of deliberate design. Yet we see no out of order fossils. No crossings of designs over the lines of descent, as any designer could and would do. No echo-locating cows for example. But despite literally millions of examples of claimed ID intervention we still don't know anything about how those interventions come to be. Not a *single* thing! kellyhomes

as to:
“Even the smallest change would end up leading to the … ” death of the embryo.,,, Embryo development must be precise, like a clock, and not randomly mutated due to the chances of chemistry.
This exact line of reasoning is behind this video and article by Paul Nelson:
Modern Synthesis of Neo-Darwinism Is Dead - No Evidence For Body Plan Morphogenesis From Embryonic Mutations - Paul Nelson - video http://www.metacafe.com/watch/5548184/modern_synthesis_of_neo_darwinism_is_dead_paul_nelson/ Understanding Ontogenetic Depth, Part II: Natural Selection Is a Harsh Mistress - Paul Nelson - April 7, 2011 http://www.evolutionnews.org/2011/04/understanding_ontogenetic_dept_1045581.html
bornagain77

This is Paley's "watchmaker argument" in real life. Are we to believe that the "watch" came into existence through blind processes? Put another way, if exquisite precision is needed for proper embryonic development, then where did this precision come from? And you can't help but love this quote: The DNA strand acts a bit like an old-fashioned computer punchcard, delivering specific instructions as it progressively goes through the machine. Gee, cellular processes are just like what computers do. And, of course, we all know that computers arose through blind processes. PaV

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