Evolutionary Scrap-heap Challenge: Antifreeze Fish Make Sense Out Of Junk DNA

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Science Daily reports Evolutionary Scrap-heap Challenge: Antifreeze Fish Make Sense Out Of Junk DNA

Scientists at the University of Illinois have discovered an antifreeze-protein gene in cod that has evolved from non-coding or ‘junk’ DNA. Since the creation of these antifreeze proteins is directly driven by polar glaciation, by studying their evolutionary history the scientists hope to pinpoint the time of onset of freezing conditions in the polar and subpolar seas. Professor Cheng will present her latest results at the Annual Main Meeting of the Society for Experimental Biology in Canterbury on Tuesday the 4th April

Hattip Pete Dunkelberg

The abstract reads

Old proteins and DNA, new tricks: Molecular evolution of antifreeze proteins in polar fishes C.Cheng (University of Illinois) Hyposomotic marine teleost fishes endemic to icy, freezing polar or subpolar waters face constant threat of freezing death. This was overcome in various species by the evolution of novel antifreeze proteins (AFPs), which bind to incoming ice crystals and arrest their growth, thereby preventing organismal freezing. The conventional paradigm of molecular evolution of novel proteins predicates on the “recycling” of pre-existing protein genes from which new genes arose under natural selection. Expectedly, by meaningful sequence similarities, four of the known AFPs (type II, III, IV and V) have inferred protein ancestors of unrelated functions, but presumably possessed structural elements with incipient affinity for ice and became selected upon. The genes of these AFPs arose from simple duplication of their respective ancestral gene (or gene domain), and the protein acquired robust ice-binding properties through cold-driven evolutionary tinkering of the coding sequence. A remarkable twist to this conventional gene-duplication/sequence-divergence paradigm is the creation of a unique functional antifreeze glycoprotein (AFGP) sequence from partly non-coding DNA in Antarctic notothenioid fish, involving de novo duplications of a 9-nt sequence spanning an exon-intron junction of an ancestral trypsinogen-type protease gene to form a large, highly repetitive (ThrAlaAla)n coding region, and shedding most of the protease gene structure. More remarkably yet, and apparently defying the old-to-new protein evolution paradigm is the independent genesis of the northern cod AFGP, which appeared to have drawn on entirely non-coding DNA for de novo expansion to form the repetitive AFGP coding sequence, creating sense from non-sense DNA.

Dr Cheng’s website provides access to much of her research publications.

The evolution of antifreeze in fish has been a well described example of gene duplication divergence and exxon shuffling and even convergent evolution, now it seems that the gene responsible for the anti-freeze in fish evolved from ‘junk DNA’.

Please remind me again: How does Intelligent Design explain all this?

Poof?…

13 Comments

PvM — You really don’t need reminding. Goddidit! :-)

OMG!!!

Front loading confirmed!

(just anticipating the reactions at uncommon dissent) :/

Please remind me again: How does Intelligent Design explain all this?

Intelligent Design specifically prohibits this from happening in the first place by the Law of Conservation of Information. Since genetic information can only decay and not increase, evolution of AFPs from non-coding DNA never happened (twice). Q.E.D.

Yeah, I talked about that news on my show when it came out - pretty cool.

http://www.inoculatedmind.com/?p=64

I think what they would try to say about it is that the “Junk” DNA is instead put there IN ORDER TO EVOLVE new genes as needed. Designed to evolve. So now, every confirmation of evolution is a confirmation of design!

Yeah, I remember talking about this news on my show last year when is came out. Pretty cool

http://www.inoculatedmind.com/?p=64

Their explanation would be along the lines of saying that “JUNK” DNA is not “junk.” The junk DNA is instead DNA designed to EVOLVE new genes when the organism needs them. So, every confirmation of evolution is instead a comfirmation of design!

oops, I thought it lost my first post.

Please remind me again: How does Intelligent Design explain all this?

They will simply deny it as they would deny Alu exonisation.

Silly Darwinists!

This just means they lost the information about how to freeze!

Cool stuff. ;-)

Re “The junk DNA is instead DNA designed to EVOLVE new genes when the organism needs them.”

Do you suppose that this happens often enough (getting a useful gene out of the “junk”) to balance the cost of keeping all that “junk” DNA in the genome? (Esp. if that cost is fairly minor, as it might be in eukaryotes?)

Henry

You have to remember the ID crowd don’t like evolution unless they want to. If it is obvious that even they know they’ll look silly denying it then they’ll say they thought of it. I just got band from UNCOMMON DISSENT (yes I know it’s DECENT) for suggesting one of the loopy Bloggers hadn’t read much on a particular subject. http://www.uncommondescent.com/archives/1981

On the tread were they were talking about the flood and how it affect the animals I didn’t see this fruit loop telling the poster that ID supports evolution. Yet I’m not allowed to say that, I only had a few posts on UD I knew I’d get banned soon enough, they only like fan boys on that site. But not once did any of the Bloggers actually ever point out to the creationist posters that some part of evolution that they (IDist) were happy with so it was a reasonable assumption that she didn’t think evolution happens. I think if there is ever another Dover trial you’d only have to point to some of the treads on that site to prove IDer’s are creationist.

the “Junk” DNA is instead put there IN ORDER TO EVOLVE new genes as needed. The junk DNA is instead DNA designed to EVOLVE new genes when the organism needs them. So, every confirmation of evolution is instead a comfirmation of design!

That’s just theistic evolution, not ID.

I’m not sure whether everyone understood I was being sarcastic or not.

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This page contains a single entry by PvM published on January 20, 2007 12:38 AM.

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