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Scientists Discover Mechanism That Gives Shape to Life
First time accepted submitter mcswell writes "Daniël Noordermeer and Denis Duboule, two researchers at Ecole Polytechnique Fédérale de Lausanne and the University of Geneva claim to have discovered how vertebrae get built in sequence in embryos (and by extension, how ribs, arms and so forth wind up in the right place). The story is that the DNA strands contain a linear series of HOX genes, and that the strands slowly unwind over a period of two days, successively exposing each HOX gene, thereby allowing it to be transcribed to form the segments of the vertebra. Snakes, it seems, have a defect that causes the system not to shut down; eventually it 'runs out of steam.' The same process is said to apply in many invertebrates, including worms (presumably segmented worms) and insects."
Now if only we can find the gene that causes ignorance.
"No matter where you go, there you are." -- Buckaroo Banzai
What a Hox gene might be
Slashdot, fix your code or at least hire someone who is competent at it to do it for you.
Well, this is the creationist version of how snakes get their shape anyway
Monstar L
A watchmaker made of tides and magnets?
I think I'll call it Evolution.
"The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
TFA is saying that organisms are built in slices, from the tip of the head down to the tip of the tail. These slices are activated in order, from first to last. It is the same in fruit flies, worms, whales, dogs, monkeys, deer and humans. The HOX genes control the basic sequence, like a player piano roll or a series of punch cards.
The reason we get so many different organisms, like whales, fruit flies and elephants, is evolution.
The gene that controls procrastination
No, it merely affirms that all the other less precise mechanisms did not survive.
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
A caveat as I write this critique, I have only read the linked article and the abstract of the original scientific article, not the full Science article.
Also, I'm a Ph.D. in Developmental Biology from 2000.
If unwinding the super-coiled DNA is considered the chronometer for embryonic segmentation, what makes the DNA unwind at such a specific time? I'm not sure how much new light is shed by this work. We've known for >20 years that transcription factors help "open" DNA for the transcription process. We've also known for >20 years that HOX genes in their clusters are the masters of structural differentiation. Put these two facts together and we can see it should be obvious that the HOX genes need to be "opened" sequentially.
In the end, we are left with the still burning question of "What controls the HOX genes and their clusters?"
If there's an omnipotent, omniscient creator of the world, then nothing can "happen by accident." Ergo, in such a universe you would have no means to distinguish accident from non-accident.
The sinuous body of the snake is a perfect illustration. A few years ago, Duboule discovered in these animals a defect in the Hox gene that normally stops the vertebrae-making process. “Now we know what’s happening. The process doesn’t stop, and the snake embryo just keeps on making vertebrae, all identical, until the process just runs out of steam.”
Looks more like a feature than a bug to me. Another fine example of evolution by mutations.
Escher was the first MC and Giger invented the HR department.
an infinite loop error?
Given how old and successful snakes are as a life form, I'd hardly call this a "defect". Just a "fascinating difference" in how the genes are expressed.
it will grow from the top to the bottom, one slice at a time
First the neck, then the thorax, then the lumbar, and so on,”
I wonder how two headed snakes happen. According to TFA, I can imagine how a snake head could have two bodies, but I've never heard of that.
So what is the implication of the defective snake? What happens if we could repair this defect? Would it grow to encompass a different form? Or would it just be a shorter, fatter snake?
I'm sure there's a joke to be made here somewhere...
From Wiki
Non-coding RNA (ncRNA) has been shown to be abundant in Hox clusters. In humans, 231 ncRNA may be present. One of these, HOTAIR, silences in trans (it is transcribed from the HOXC cluster and inhibits late HOXD genes) by binding to Polycomb-group proteins (PRC2).[19] The chromatin structure is essential for transcription but it also requires the cluster to loop out of the chromosomal territory.
-KI
#include bier;
Perhaps the best excuse I've heard from advocates of intelligent design was that God creates families, and well-documented processes of microevolution create genera and species within those families.
Does anyone have any better trolls than this? Just staring at it is making me bored.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
I think the significant finding is how the layers are timed or sequenced....they knew that embryos develop in layers, they just didn't know how that was achieved. Now they do: layer after layer of the relevant DNA is exposed via a mechanical unwinding of the HOX genes.
AB HOC POSSUM VIDERE DOMUM TUUM
(reposting as myself, sorry.) Attempts to explain the mechanics of DNA leave me with so many burning questions I end up as a bemused pile of ash with some ACGT letters in it. Besides "What controls the HOX genes and their clusters?"
I'm in awe that we can puzzle out our own creation, but either our understanding or the explanations of it are riddled with gaps.
=S
It all hinges on the precise meaning of the word translated "kind" in Genesis 1:21-25 and 6:20. I guess a creationist would argue that a "kind" is very close to a modern taxonomic "family" but not exactly the same: humans aren't the same "kind" as orangutans, gorillas, and chimps, created during the fifth period, despite their modern classification into Hominidae. Humans were created during the sixth period of creation as God's attempt to see how many of his own qualities he could squeeze into free space in the chimp genome.
Indeed it does. A blind watchmaker, to be precise.
"Money is a sign of poverty." - Iain Banks
A few years ago I found out that the explorers in the science of paper folding have proposed that any three dimensional physical object can be formed by folding a single sheet. That resonated with my contact with embryology (which included watching frog eggs divide under a stereo microscope). And it still resonates with my work with special education kids where I puzzle about which layers of their motor skill function stack are not working well.
So another burning question, or at least request for explanation is: What is the shape and structure of the embryo before the HOX genes begin unwinding. What is the shape and structure when the second HOX gene begins acting? Is there a neural tube present at this time? Does the HOX gene start a series of surface tension changes in a single cell that sets off an extrusion?
I think stuff like this should be touted as proof of Intelligent Design... not to prove God exists but to reconcile American fundamentalist Christian ideas with science. And from there push the meme that God wants us to examine the world and understand his creation so we can bask in the wonder of His glory. Then maybe they'll ease up on trying to oppose science sometimes.
Question: How do the Jesuits feel about biological science vs. intelligent design? I assume (with total ignorance of their ideas on the subject) that they acknowledge evolution?
Deltron 3030 - Virus (music video)
Wow!
Decades ago, in ninth grade biology class, I asked my biology teacher how a Hydra (or other creatures) knows how to form its shape from cells, but he hemmed and hawed, and essentially would not admit that he did not know, or even that no one knew. We had been supposed to look at some Hydra in class, but they never arrived or something like that. I later studied Hydra in Ecology and Evolution grad studies, but people still did not quite know how they formed their shapes.
A couple lessons there for me I guess including the one about some teachers and authority:
http://www.newciv.org/whole/schoolteacher.txt
http://www.johntaylorgatto.com/chapters/16a.htm
In pretty much every other way he was a great teacher from my point of view back then though (aside from not being willing to admit he did not know something), because he went covered a lot of material in an interesting way, and was obviously very proud of his knowledge. He definitely sparked my interest in biology with the way he ran the class, the way he handled that question aside. Anyway, thanks for everything Mr. Nast -- one of your students went on to biology graduate studies and making biology-related software made possible by the great job you did in some blue collar high school on Long Island.
Plants work somewhat differently from animals though. My wife and I implicitly used some of the ideas related to auxins etc. in this software we wrote to breed virtual 3D plants:
http://www.kurtz-fernhout.com/PlantStudio/
https://github.com/pdfernhout/PlantStudio/blob/master/README.txt
A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
so is there another clock that turns on this clock?
My guess is yes, there is something else. It may not be a protein but a small nuclear RNA.
but when new cells form in that area weeks later, how do they know their place?
Molecular landmarks sort of like what makes one intersection different from another even if both have a coffee shop, a fast food place, and a gas station. The landmarks could be on the cells, on the extracellular matrix, a diffusable protein gradient, or some other way to differentiate an environment.
Is the HOX system reused to control the layout of my arm down to five jointed fingers? If not, what takes its place at lower levels?
Actually, they are. Nature likes to re-purpose genes temporally and spacially to do more than 1 thing when in the correct environment. Scientists have a decent understanding of how fingers in a mouse and a rat are made. It's quite interesting how expression of one Hox gene creates fingers while the another one is required to create the space between our fingers.
What if someone were to take a newly created snake embryo and repair that 'defective' gene before letting it develop further? Would it automatically develop four limbs and look more like a lizard? Whatever the result, if successful it might give us some more insight into how these fascinating creatures evolved.
Obligatory post by a plant biologist who is sick of the animal folks overgeneralizing their findings in press releases.
The 1st thing that comes to mind is the possibility we could construct things out of organic material now. Instead of cutting down a tree to build a house we could organize tree DNA to deliver a real tree house. Patent pending.
'I don't know what it's called. I just know the sound it makes, when it takes a man's life.' ~ Four Leaf Tayback
Does this mean that lawyers have mutated HOX genes that fail to unwind, thus leaving them spine-less?
"Does the HOX clock run in every cell? If not, which ones? If each one, what keeps them in sync? Some cells are 3 days old during this process, some are brand new"
I'm the original OP, and yes, I wondered about this too--particularly how the current unwinding gets transmitted down the length of the animal as the cells undergo mitosis. Or maybe it only unwinds a little with each division, and only the cells at the posterior end (which I presume are in the last segment produced) govern further division? Except that the anterior cells must be dividing too, if the anterior end continues to grow (which it obviously must, sooner or later, otherwise we'd have pinheads).
It's an interesting story, but there are lots of unanswered questions.
Galileo was a long time ago. The Catholic church, by now, has no beef with the well-settled science on Evolution, the Big Bang, etc.
Although I'm not quite sure what process they use to decide which parts should be taken literally (i.e. the resurrection of Jesus) and which should be discarded as poor translations of ancient epics (the seven days of Creation, Adam and Eve, etc.)
And it baffles me that any form of Christianity decided to include Revelation; whoever wrote that had clearly discovered some Magic Mushrooms...
Organic 3D printing, okay. The printers are cheap but you have buy 18 years worth of expensive ink cartridges in a manner of speaking.
Snakes have a defect!!! Then, they ARE in league with the devil! Grandma was right all along!
Crap, Annon, you beat me to it. It's only a defect if what you wanted is not a snake, for them is a feature. Opinions may vary but I for one don't feel so defective because I don't have gills or feathers for instance...
+Raider of the lost BBS
So how do I get this gene to express itself as greater penis size?
This discovery also illuminates another aspect of growth. Sure, you can build in a slice fashion, but obviously the initial full structure will not have full internal (neural) communications, because that can only be grown point to point AFTER the points are built. So this explains why infant maturing involves such massive neural growth. The building has been constructed, now the phone and IT infrastructure gets built up, over years. Plus, the building keeps getting improvements and expansions, so wiring has to be dynamically upgraded for the first 18 to 20 years. This also gives me some ideas for dynamic AI architectures, so whoo-eee! Fruitful discovery.
It didn't happen just by accident, it happened by an uncountable number of accidents all starting where the last one left off.
404: sig not found.
A "god" can be omnipotent without being omniscient. For example, suppose you ran a powerful simulation on a Linux box(es) of a universe and it evolved intelligent life. You'd essentially become a "god" to that universe and be omnipotent. (We may be in such a simulation and couldn't tell the difference.)
You could poke into the code and data and fuck with anything you wanted. You are omnipotent because every actual bit is under your control. However, you will not know all the details in the simulation, and are thus not omniscient.
(I hope God makes backup tapes)
Table-ized A.I.
Allow me to point out that an "omniscient" and "omnipotent" god would have no need to attempt anything.
"Attempt" was sloppy wording, for which I apologize. Grammatically, I needed a noun in that position.
And being omniscient he would know the outcome of any such attempt without trying.
The current age is how God demonstrates to the not-omniscient created beings (spirit creatures and humans) that man cannot effectively rule man.
whoo-eee! Fruitful discovery./quote.
Well, informative discovery would probably be more correct. NOW we will see if this discovery will actually bear fruit in finding therapies or the ability to correct for certain early birth defects such as Spinda Bifida.
Official Heretic from the "Church of Global Warming". Proven right thanks to whistle blowers. AGW = Flat Earth Theory
"The reason we get so many different organisms, like whales, fruit flies and elephants, is evolution" That's irrelevant here.
As for the article, the most interesting part is that instead of traditional regulation, where genes are turned on and off by specific interactions of gene area with other molecules (proteins, microRNA), the authors propose a mechanical mechanism where active and inactive HOX genes are spatially segregated in two blobs of DNA.
The question is what mechanism provides persistent of this blobs arrangement during mitosis. DNA replicates during mitosis which requires dissolution of the spatial arrangement of DNA that existed in the parent.
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
It's turtles all the way down.
The current age is how God demonstrates to the not-omniscient created beings (spirit creatures and humans) that man cannot effectively rule man.
And you know this... how?
The way of man does not belong to man (Jeremiah 10:23). Satan has challenged God, calling him a liar who withholds good from humankind (Genesis 3:2-5), right in front of millions of angels (Job 38:7; Daniel 7:10).
You didn't address the other point, which was that trying to ascribe intent to an omnipotent and omniscient being is nonsense.
God makes his intent clear in the Bible. He built this earth to be inhabited (Isaiah 45:18) by human beings who serve him. And he always fulfills his purposes (Isaiah 55:10-11), even when other forces make him change exactly how those purposes will be fulfilled.
[God] should know the proper way or ways to ensure that everybody will believe
And this proper way is not by forcing people to believe something. It's by allowing this system of things, which is ruled by Satan (1 John 5:19), to play out to its inevitable conclusion among nonbelievers. God knows that we humans are collateral damage in this demonstration, which is why he provided the ransom in the death of his son Jesus "to break up the works of the Devil" (1 John 3:8) and make everlasting life possible (John 3:16).
Secondly, Adam and Eve didn't know good from evil before eating the fruit
But they knew their maker from a snake in the grass.
Christian theology associates the serpent with Satan, although there is nothing in the story itself to indicate this.
Explicit identification of the serpent with Satan is found later in the Bible. John of Patmos wrote in Revelation 12:9 of "the original serpent, the one called Devil and Satan, who is misleading the entire inhabited earth".
If Satan tempted man, it's because God allowed it.
God allows evil to exist to illustrate a point: that evil is a destructive force that man cannot contain alone.
given the premise that there is evil in the world: is God evil, is he not omniscient, is he impotent to stop it, or does he simply not exist?
Allowing evil != being evil. God hates evil more than people do, but it's there for a reason. For one thing, it helps people appreciate the coming paradise more because they know what they'll be leaving behind. See what Watch Tower has to say about why God continues to allow evil for the time being.