Coelacanth Genome Sequenced

damn_registrars writes "The lobe-finned fish described as a 'living fossil' due to its apparent lack of change for hundreds of millions of years (thought to be extinct until the 1930s) has been sequenced by an international team, including scientists from Sweden, Harvard, and MIT. The 3-billion-base-pair genome of the Coelacanth was described yesterday in the journal Nature. This paper is published in an open (non-paywalled) manner on Nature, making the full text available to all. 'We found that the genes overall are evolving significantly slower than in every other fish and land vertebrate that we looked at.'"

Comments

Why Evolve

[zenrandom]

They don't really seem to have any convincing external factors to make them evolve. I have not RTFA'd, but most things evolve because they have trouble surviving. There are so few of these things that they are endangered, but they don't have any natural predators because they apparently make anything that eats it sick... check the wikipedia article on them.

That kind of longevity is awesome

[GodfatherofSoul]

It's amazing to think that a species is so well adapted that it's survived numerous extinction events and still looks relatively the same. Three hundred million years ago, this planet would have looked like an alien world!

Re:That kind of longevity is awesome

[Tablizer]

My understanding is that it has a very efficient metabolic system that allows it to survive famines. It's comparable to some snakes: sit quiet in waiting for long periods of time with meals few and far between. Rather than compete with the newer younger faster whipper-snapper ray-finned fish, it found a nice little niche of hiding out and cruising.

Re:That kind of longevity is awesome

[Anonymous Coward]

It's preposterous to think that the ecology around this fish was changing substantially over eons, and yet this fish didn't adapt at all. Food sources were changing or going extinct, abiotic conditions were changing, predators were becoming more effective... but the coelacanth just didn't care.

It's equally preposterous to think that the ecology around this fish was UNchanging over eons, and yet that's exactly what the article suggests; "Although a static habitat and a lack of predation over evolutionary timescales could be contributing factors to a lower need for adaptation." Wow. I guess they don't have any other option - gotta come up with some story that fits the evidence, no matter how ridiculous.

but is the rate of genetic drift normal?

[schlachter]

I get that there may be low selection pressure. Are they claiming that there's also a slower rate of genetic drift? That would be interesting. I just assumed that drift would happen similarly across species, perhaps with some minor variation for body temp, metabolism, habitat (i.e. radiation exposure), etc.

Re:An obvious extrapolation...

[LateArthurDent]

"...We found that the genes overall are evolving significantly slower than in every other fish and land vertebrate that we looked at.'"..

Which indicates that their environment has hardly changed in many million years...

It can also mean they're fairly robust and can survive in a large range of environments. I think that's more likely considering the other fish sharing the same environment has evolved faster.

That said, it's not like the ocean is dominated by coelecanth, so it doesn't mean they've reached optimality or anything. Just that they're good enough to continue reproducing and surviving.

Re:ATTENTION SLASHDOT ADMINS ... apk

[interkin3tic]

Why not just prevent posts from ACs, new accounts, or accounts with negative karma from going up for, I dunno, half an hour on a story?

Or maybe reorder comments so that they're by score and not first posted by default? Maybe don't jump right into it. There's this little website called reddit that does it that way, maybe slashdot should wait and see if that catches on before making the jump. Maybe people really like completely off-topic posts as the first thing they see?

I get the feeling that slashdot is trolling me these days. They're still updating stuff, but not bothering to fix that.

How do they measure that?

[__aaltlg1547]

The article was pretty sketchy on details. How do they establish how fast coelecanth genes are changing? It's not like they can break open a package of 300 million year old coelecanths and sequence the ancient genome. You have to compare it to other modern animals.