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Coelacanth Genome Sequenced 82

Posted by Soulskill
from the elderly-base-pairs dept.
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.'"
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Coelacanth Genome Sequenced

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  • Why Evolve (Score:3, Interesting)

    by zenrandom (708587) * on Friday April 19, 2013 @04:13PM (#43497637) Journal
    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.
    • I believe they are cousins of the lungfish, so their evolutionary spawn may have escaped notice since they are no longer sea-bound.
    • by djl4570 (801529)
      That was my thought. Evolution requires selective pressure that causes certain traits to become assets or liabilities. The coelacanth fills an ecological niche and doesn't have much if any competition in that niche except from other coelacanths.
      • by Shavano (2541114)

        That was my thought. Evolution requires selective pressure that causes certain traits to become assets or liabilities. The coelacanth fills an ecological niche and doesn't have much if any competition in that niche except from other coelacanths.

        Competition from other members of the same species is supposed to be one of the major drivers of natural selection.

        • Re: (Score:3, Insightful)

          by Anonymous Coward

          But why would natural selection lead to significant evolutionary diversification if maintaining the status quo is closest to the optimal solution? In that case, wouldn't selection work to keep things more of the same? I'd suspect those fish probably aren't alone in being "genetically old", there are likely some insects and creatures like jellyfish that really haven't evolved much since some wormlike thing had the luck to spawn the first vertebrate. Thus plenty of critters we have now aren't really all that

    • by flyneye (84093)

      Behold, a species perfectly comfortable in its environment. No motivation, probably just swims around all day gloating at its luck.

  • ...and I didn't even notice.
  • by GodfatherofSoul (174979) on Friday April 19, 2013 @04:16PM (#43497673)

    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!

    • by Tablizer (95088) on Friday April 19, 2013 @04:53PM (#43498153) Homepage Journal

      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: (Score:1, Interesting)

      by 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 ti

      • by Joe Snipe (224958)

        We have the ability to compare this fish to actual fossils from the time, your incredulity notwithstanding. What boggles my mind is why ancient life has so many more gene pairs than current life. It's like we are being sculpted from some master block of genes.

  • by Anonymous Coward

    "...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...

    • by LateArthurDent (1403947) on Friday April 19, 2013 @04:31PM (#43497863)

      "...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.

      • by b4upoo (166390)

        One wonders how these critters prosper. It may be that they taste lousy to predators or that they simply can get by in such stark environments that they don't have to compete much to get by. But if the gene sequence is available I would think we could cross breed some species and perhaps generate a fish of great use to humans. Cross breeding species seems to not be mentioned a lot but surely the scientists are trying it out. Is it so hard to do something like cross breed a trout with a bass

        • by cusco (717999)
          Is it so hard to do something like cross breed a trout with a bass or a catfish with a carp?

          Yes, they're different species, they can't mate successfully. If you actually mean splicing genes from different species together to make a chimera of some kind I'm sure that some are trying it, but plants and insects are a lot easier to work with and more profitable.
      • by heson (915298)

        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.

        I would say that their genes are stuck in a local maxima where they can't evolve. Any mutation dies off or are so different that they leave the area and become a new species.

  • by schlachter (862210) on Friday April 19, 2013 @04:30PM (#43497853)

    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.

  • "genes overall". I wasn't aware my overalls HAD genes!

    • by Livius (318358)

      You're thinking of overalls genome sequencing.

      Gene overalls are overalls for genes.

  • by Anonymous Coward

    after reading the first 20000 base pairs. Yawn...

  • Sadly no longer a Googlewhack.
  • by Mystakaphoros (2664209) on Friday April 19, 2013 @06:46PM (#43499179) Homepage
    *shakes its non-evolved fist* Those damned kids...

    If Coelacanth had a front porch, it'd be stealing our baseballs and yelling at us.

  • It's a known fact here in Brazil.
  • Woah (Score:4, Funny)

    by wakeboarder (2695839) on Friday April 19, 2013 @07:51PM (#43499669)

    The first time I read it I thought it said Cthulhu genome sequenced, now that would be impressive.

  • by Shavano (2541114) on Friday April 19, 2013 @11:15PM (#43501057)
    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.
    • I don't know how strong your biology, specifically genetics, background is, but they do explain how they established the rate of change (the second paragraph under the heading "The slowly evolving coelacanth"). I will try to keep my explanation of that second paragraph succinct and simplified, so it might not satisfy your curiosity. But, you can also consult the methods, which are in a linked PDF document (bottom of page 8, through to page 10).

      Due to random copying errors during DNA replication, a base pair

  • I fail to see how this article is worthy of being on the front page. Sure, the fish itself was an interesting find in 1938, but we have been sequencing DNA for years now - what's so special about this paper?

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