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Deep-Sea Microorganism Hasn't Evolved For Over 2 Billion Years

sfcrazy writes: Evolution is a natural process — everything evolves over a period of time, depending on the environment. But now scientists have discovered an organism which hasn't evolved for over more than 2 billion years. That's almost the half of the life of the Earth. "The scientists examined sulfur bacteria (abstract), microorganisms that are too small to see with the unaided eye, that are 1.8 billion years old and were preserved in rocks from Western Australia’s coastal waters. Using cutting-edge technology, they found that the bacteria look the same as bacteria of the same region from 2.3 billion years ago — and that both sets of ancient bacteria are indistinguishable from modern sulfur bacteria found in mud off of the coast of Chile." Scientists say the extreme stability of the environment around the organisms made further adaptations unnecessary.

25 of 138 comments (clear)

  1. uhhh by bob.lansdorp · · Score: 4, Interesting

    Just because a fossil looks similar does not mean it hasn't evolved. Most evolution happens on the molecular scale, if you looked at the genomes I guarantee they would be different.

    1. Re:uhhh by JumperCable · · Score: 2, Informative

      I agree with your primary point. However the article does state he analyzed the chemistry too. I wonder how much the chemistry is really going to change if the microbes are pulled from the same environment. I would expect proteins to break down after a couple of billion years.

      Schopf used several techniques to analyze the fossils, including Raman spectroscopy — which enables scientists to look inside rocks to determine their composition and chemistry

    2. Re:uhhh by Em+Adespoton · · Score: 3

      He doesn't need a methodology for analyzing the changes to point out that the scientists could not arrive at the conclusions presented in the media (not I'm not saying they arrived at those conclusions) without such a methodology.

      I'll add to that that the information as presented in TFS does not prove or disprove that descendents of the original bacteria evolved -- it just shows (if you accept their methodology) that at least some of them didn't, at least not in the ways the scientists were measuring.

      Since these bacteria DO use DNA, which has built-in mutation weaknesses, this is impressive no matter how you look at it. It is possible we will find that they have some process that inhibits the mutation of their genome in a significant portion of their culture.

    3. Re:uhhh by Phronesis · · Score: 3, Interesting

      Just because a fossil looks similar does not mean it hasn't evolved. Most evolution happens on the molecular scale, if you looked at the genomes I guarantee they would be different.

      The paper in PNAS discusses this at length. It clearly states that it would be very nice to be able to check DNA, but that defining species in microbes is about phenotypes, not genotypes, and the important thing is that there is no sign of speciation (that is, two separate populations, separated in space, did not diverge.

      The morphology-based “concept of hypobradytely does not necessarily imply genomic, biochemical, or physiological identity between modern and fossil taxa," a claim of extreme evolutionary stasis—a lack of speciation over billions of years—would be strengthened not only by discovery of additional fossil communities but by firm evidence of their molecular biology. Although speciation-based evolution occurs at the phenotypic rather than genotypic level of biologicenvironmental interaction, the biomolecules underlying such change are not preserved in the rock record in which such assessment can be based only on indirect proxies and inferences of physiology based on isotopic analyses

      However, the article noted, it's possible that this interpretation is wrong and that what they saw was two separate populations that underwent convergent evolution rather than one population that was separated and remained static or that there might have been significant biochemical evolution that did not change the morphology.

      Moreover, large-diameter (“giant”) sulfur bacteria of differing phylogenetic lineages can exhibit similar morphologies and patterns of behavior suggesting convergent evolution of morphologic “look-alikes” adapted to a same or similar function. Although it remains to be established whether such morphological “mimicry” is exhibited also by the more narrow 10-m-diameter sulfur bacteria described here—the two modern sulfur bacterial taxa of similar dimensions being aerobes rather than anaerobes like the Duck Creek and Turee Creek fossils—it remains conceivable that the marked similarities between the two mid-Precambrian communities and their modern counterparts could be an example of the so-called Volkswagen Syndrome, a lack of change in organismal form that masks the evolution of internal biochemical machinery

  2. Re:Plenty of other creatures haven't "evolved" by BlackSWE · · Score: 2

    ~2.3 billion years > ~35 million years. Just saying...

  3. Visual only by Tablizer · · Score: 3, Interesting

    They seem to be going by visual appearance. There may be loads of DNA changes that affect metabolism chemistry and behavior that wouldn't be detectable by visual inspection of fossils. Looks can be deceiving.

    Also in the TFA: "If they were in an environment that did not change but they nevertheless evolved, that would have shown that our understanding of Darwinian evolution was seriously flawed."

    It's possible for a chance mutation or set of mutations to "discover" a new feature even in a stable environment. There are probably always better designs in highly remote combinations of mutations.

  4. Re:Plenty of other creatures haven't "evolved" by MightyMartian · · Score: 5, Informative

    Morphological changes may have been minimal, but I suspect genomic changes have still occurred. Neutral drift alone would assure that these bacteria were not identical at the molecular level to their two billion year old ancestors.

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  5. If it ain't broke don't fix it by TrollstonButterbeans · · Score: 2

    Is part of evolution

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  6. Re:Why Evolve? by Rob+Y. · · Score: 3, Interesting

    If they reproduce asexually, then evolution has to count only on random mutations and copying errors. Sexual reproduction intentionally mixes up the genes so you get new combinations all the time. Evolution based on random mutations that still produce a viable organism is closer to monkeys at typewriters.

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  7. Looks good enough for science writers by nowsharing · · Score: 2

    To summarize: Fossils that look similar "haven't evolved". That is quite possibly the stupidest thing that I read today.

  8. bacteria ... too small to see with the unaided eye by Nutria · · Score: 3, Funny

    Has our educational system sunk so low that it must be mentions that you need a microscope to see bacteria?

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  9. Re:bacteria ... too small to see with the unaided by quenda · · Score: 4, Informative

    Most, but not all.

    e.g. http://en.wikipedia.org/wiki/T...

  10. Re:Why Evolve? by presidenteloco · · Score: 4, Informative

    In a simple and stable environment, the critters could have adapted a locally optimal form and strategy (given the evolutionary path they had already taken), to the point where all variations reachable from the current form function worse and are selected out. "reachable" is key here. You (your lineage) are very unlikely to evolve into spherical iron rock crystal creatures of roughly the same mass. The relative Kolmogorov complexity to get your form to that form, as well as the energetic infeasibility, mitigate against that direction, no matter how random evolutionary variation is. There are always constraints, not only on survival probability, but also on variation direction possibility.

    This has zero to do with religion. It's about combinatorics, complex system constraints, and non-equilibrium thermodynamics.

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  11. Re:bacteria ... too small to see with the unaided by ihtoit · · Score: 2

    Not so, some are large enough to see with the naked eye: Sogin, Nature, vol. 362, page 207

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  12. Re:Summary is wrong by Barsteward · · Score: 3, Funny

    Species, Species II, Species III and Species - the awakening . http://speciesfilms.wikia.com/...

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  13. Re:Earth has only existed for six thousand years. by l0ungeb0y · · Score: 2

    Hmmm ... I don't think WASP means what it think it means. White Anglo-Saxon Protestant is typically used to describe lacoste clad and teeth whitened mcMansion types, not bible banging NASCAR fans

  14. Re:Plenty of other creatures haven't "evolved" by unrtst · · Score: 5, Insightful

    sometimes there is no force nor need for evolution.

    .. and from TFS:

    ...made further adaptations unnecessary.

    It really bugs me when I see the theory of evolution referred to this way. There is no "need" or "desire" or "necessary" involved. Similarly, "survival of the fittest" has nothing to do with who is in the (subjectively) best shape or who is the smartest (though there may be correlations). Fish did not decide that they'd like to walk on land or breath air (if they did, it had nothing to do with that happening).

    If these things haven't evolved in 2 billion years, it simply means that any mutations that may have occurred resulted in lines that did not reproduce as effectively. That's still a very impressive feat, but it's not because it didn't "need" to, it's because when it did change it didn't do as well. In this case, it's very likely that this is at least partially due to the simplistic nature of this bacteria (fewer dip switches in its DNA, so to speak) and, of course, as the article points out, the very consistent environment (allowing for an optimized implementation to consistently out perform any random brethren).

  15. How can the prove that the sulfur bacteria has not by TimSSG · · Score: 2

    How can the prove that the sulfur bacteria has not evolved? Note: They could prove that the sulfur bacteria still exists like it did long ago. But, I see no way they can prove there was NOT failed evolution paths taken in the past. And, I am NOT sure that there has NOT been evolution paths taken in the past that has resulted in bacteria so different that it might not be currently believed they evolved from this sulfur bacteria. Tim S.

  16. Re:Plenty of other creatures haven't "evolved" by Chikungunya · · Score: 2

    I have always interpreted the "need" or "necessary" as the requisites that have to be fulfilled in order to find a certain organism in a certain place today (or whatever time they are talking about). So yes, the organism or the species don't "need" adaptations, they just survive or not, but you "need" the adaptations in order to explain how they can survive there. This kind of place "need" very few explanations because there is not real change and any organism that could survive at the beginning could just keep doing it.

    Nevertheless, this finding assumes quite a lot of things, they compared the morphology of fossils with modern organism and propose that the lack of visible differences means no adaptations, also they compared bacteria from two distant geographical places and assumed that this means genetic isolation (likely but not certain). I would prefer if they waited until they could report on both modern bacterial genomes (trivial task nowadays) before making such bold conclusions.

  17. Re:Plenty of other creatures haven't "evolved" by lgw · · Score: 3, Insightful

    Lamarck called; he wants his discredited theory back.

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  18. Re:Plenty of other creatures haven't "evolved" by rubycodez · · Score: 2

    A wasp is a very complex multicellular organism though, and yet it stopped evolving so long ago. The american alligator species is 150 million years old !

  19. Re:Plenty of other creatures haven't "evolved" by jdschulteis · · Score: 3, Insightful

    I would think that any organism would seek a better or easier path and perhaps come back to center as no gain was found but I think the drift would be endless even if the return to center is endless. Otherwise we would have to explain the ability of an organism to simply be content and intelligent enough to stop trying to change.Other than a decision making process the only other explanation might be divine intervention.

    There is no seeking, no contentedness, no intelligence, no decision making process, and no divine intervention.

    There is only a stable environment, in which no mutations have occurred that conferred a reproductive advantage.

    There is beauty in simplicity.

  20. Re:Why Evolve? by jdschulteis · · Score: 3, Informative

    How did eyes evolve? The structures are too complex to be accounted for by traditional evolutionary explanation mechanisms.

    That old chestnut? Open your eyes.

  21. Re:Plenty of other creatures haven't "evolved" by GNious · · Score: 2

    ~2.3 billion years > ~35 million years > 6000 years old planet

  22. Re:"cutting edge technologies"? by RockDoctor · · Score: 2

    The likelihood of getting a vaguely complete DNA sequence from multi-billion-year old fossils is slender. Our best example of "ancient DNA" from fossils has a less than 1% complete genome from rocks a little over 100Myr old. 2000 Myr old fossils might have a 0.0000000000000000001 % complete genome (if preserved in exceptionally well.

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