Genomics

“Evolution,” we are told, “can cause a rapid reduction in genome size”

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From the Max Planck Institute, we learn (April 21, 2011):

Despite being closely related to the lyre-leaved rock cress, the thale cress has a considerably smaller genomeIt would appear reasonable to assume that two closely related plant species would have similar genetic blueprints. However, scientists from the Max Planck Institute for Developmental Biology in Tübingen, working in cooperation with an international research team have now decoded, for the first time, the entire genome of the lyre-leaved rock cress (Arabidopsis lyrata), a close relative of the thale cress (Arabidopsis thaliana), the model plant used by geneticists. They discovered that the genome of the lyre-leaved rock cress is fifty percent bigger than that of the thale cress. Moreover, these changes arose over a very short period in evolutionary terms. This new high-quality genome analysis will provide a basis for further detailed comparative studies on the function, ecology and evolution of the plant genus Arabidopsis

Also,

A smaller genome appears to offer advantages during the natural selection of individuals.

Paper here free.

9 Replies to ““Evolution,” we are told, “can cause a rapid reduction in genome size”

  1. 1
    DrREC says:

    From the paper:

    “… most of the difference in genome size can be attributed to hundreds of thousands of small deletions, mostly in noncoding DNA and transposons.”

    Looks like A. thaliana dumped a lot of the ‘junk’. Wonder if there was any impact on fitness.

  2. 2
    Arthur Hunt says:

    DrREC,

    I noticed the same thing.

    Kudos to Uncommon Descent for pointing out literature that contradicts leaders of the Intelligent Design movement (such as Dr. Wells, in this case).

  3. 3
    Mung says:

    A smaller genome appears to offer advantages during the natural selection of individuals.

    Amazingly enough, a larger genome also appears to offer advantages during the natural selection of individuals!

    Nothing like having something that can explain anything with a mere wave of the hand and an occasional fanciful tale.

  4. 4
    Ilion says:

    Well, you know the old saying: “Eith ‘evolution,’ all things are possible!

  5. 5
    DrREC says:

    “A smaller genome appears to offer advantages during the natural selection of individuals.

    Amazingly enough, a larger genome also appears to offer advantages during the natural selection of individuals!”

    Depends what is being selected for, I suppose. If it is quick reproduction at low maintenance cost, a small genome would be warranted. If it is slower growth with diverse metabolism, a larger genome with more capabilities might be advantageous.

    I can’t find any literature suggesting A. thaliana has any fitness costs associated with loss of much junk DNA. It is a fast growing nearly-worldwide weedy plant.

  6. 6
    Mung says:

    Depends what is being selected for…

    Actually, no. All that matters is reproduction rate. If I leave more offspring than you, I win.

  7. 7
    DrREC says:

    Mung-

    “All that matters is reproduction rate.”

    Than bacteria have ‘won’? E. coli, for example, reproduces in thirty minutes. Why isn’t it the only organism on the planet?

  8. 8
    Mung says:

    Why isn’t it the only organism on the planet?

    Hey, no one ever said there weren’t flaws with the neo-Darwinian theory. 🙂

    Some how a new gene pool must have been created, and this must have happened numerous times, else as you point out, we would have no new species.

    As we all know by now, Origin of Species explained adaptations, but not the origin of species.

  9. 9
    zeroseven says:

    I must admit is is somewhat heartening to see that the ID movement does publicise material that contradicts one of its key arguments. This commitment to objective analysis does raise the movement in my estimation.

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