Lyme bacteria show that evolvability is evolvable

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Some gamblers succeed by spiriting cards up their sleeves, giving them a wider range of hands to play. So do some bacteria, whose great capacity for genetic variability helps them evolve and adapt to rapidly changing environments.

Now research on Borrelia burgdorferi, the bacterium that causes Lyme disease, shows that the capacity to evolve can itself be the target of natural selection. The results were published today in PLoS Pathogens

“There are other data that suggest that there could be selection on evolvability, but this is the first example where there really aren’t any other confounding answers for the data,” says lead author Dustin Brisson, an evolutionary biologist at the University of Pennsylvania in Philadelphia.

B. burgfdorferi can cause a chronic infection even if its animal host mounts a strong immune response — evading those defences by  tweaking the shape and expression of its main surface antigen, VIsE. A series of unexpressed genetic sequences organized into ‘cassettes’ recombine with the VIsE gene, changing the resulting protein such that it escapes detection by the host’s immune system.

Written By: Hannah Hoag
continue to source article at nature.com

9 COMMENTS

  1. “Chance favors the prepared genome.” – Lynn Caporale, author of “Darwin in the genome”.
    Another very good book on the subject is “The Plausibility of Life: Resolving Darwin’s Dilemma” by Marc Kirschner, John Gerhart and John Norton.

  2. I have often wondered about cave animals that lose their eyes, or birds that lose the ability to fly. Is there any way they can put that ability “in the attic”, to be turned on later if needed.

    I would think temperature adaptability might work that way, or it would be great if it did.

    • From general observation I’d say that reversing the path of vestigial organs or functions might not be as easy as we would think. Perhaps once genes or networks are broken they are harder to reconstruct than to start from zero. It’d be nice to see research on the subject.

      I have often wondered about cave animals that lose their eyes, or birds that lose the ability to fly. Is there any way they can put that ability “in the attic”, to be turned on later if needed.

      I would think temperature adaptability might work that way, or it would be great if it did.

    • The cave animals that lose their eyes retain ALL of the genes necessary to make eyes. What happens is a hox gene mutates into the “off” position. So, the eye “routine” is never accessed, but the “program” stays intact.

      So, there are genes that regulate other genes! It would be hugely unlikely that all the eye genes in an organism would “all at once: have problems. The hox gene that “sits on” the eye cascade of development turn off and so does eye production.

      Not many many mutations, but ONE!

      Awesome or what????

      In reply to #3 by Roedy:

      I have often wondered about cave animals that lose their eyes, or birds that lose the ability to fly. Is there any way they can put that ability “in the attic”, to be turned on later if needed.

      I would think temperature adaptability might work that way, or it would be great if it did.

      • But you cannot discount that with the passage of time, and not being subject to selection, those genes or networks intervening in the formation of the trait might further degenerate and make reversion quite unlikely.

        The cave animals that lose their eyes retain ALL of the genes necessary to make eyes. What happens is a hox gene mutates into the “off” position. So, the eye “routine” is never accessed, but the “program” stays intact.

        So, there are genes that regulate other genes! It would be hugely unlikely th…

        • Eduardo Sibilis,
          Excellent point.

          In reply to #7 by Eduardo Sibils:

          But you cannot discount that with the passage of time, and not being subject to selection, those genes or networks intervening in the formation of the trait might further degenerate and make reversion quite unlikely.

          The cave animals that lose their eyes retain ALL of the genes necessary to make ey…

  3. Lyme bacteria evolved to become more proficient at evolution. Cool!!!
    Except when you get Lyme disease. A friend of mine has it, and if I understood correctly, it’s pretty much uncurable so far. Uncool.

  4. Adaptability = the ability to evolve…. its two fold…Life that can’t move – must stay put and adapt to new conditions genetically or
    life that can move away – must still adapt to new habitat and conditions….
    If there is no way to genetically adapt or move away from any changing exterior pressures and conditions – surely extinction follows ?

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