Evolution is a Fact #28 - Something Darwin Didn't Say

by cofty 36 Replies latest watchtower beliefs

  • Ruby456
    Ruby456

    shepherdess

    Further to what Ruby says, if SBF (in his second post) is suggesting that phenotypic plasticity involves a change to a genome, I disagree. When read carefully and in context, particularly the next page, the paper doesn't say that at all.

    I'm not saying that sbf is suggesting that phenotypic plasticity involves a change to a genome

    glad that we agree with each other though in our readings of the text

  • Ruby456
    Ruby456

    in actual fact, cofty, the article you linked to in your opening post is suggestive of phenotypic plasticity

    edit: in other words cofty you shouldn't allow the idea that evolution only stems from changes in genes the way you define this to stymie your thinking. keep reading

  • shepherdless
    shepherdless

    Hi Ruby,

    I don't understand that last post. In fact I don't see the article linked to his post. I fully agree with your earlier posts.

    At this stage, to me, Cofty's fundamental point stands. SBF (being the contrarian he is) has pointed out a limited and interesting exception.

  • cofty
    cofty
    you shouldn't allow the idea that evolution only stems from changes in genes the way you define this to stymie your thinking - Ruby

    Evolution does "only stem from changes in genes". If the genome doesn't change no evolution has taken place.

    As Shepherdless said I didn't link to any articles in my OP but the evolution of pigeons has nothing at all to do with phenotypic plasticity.

    Put simply, some insects have genomes that allow alternative body plans to be built depending on environmental factors. It's a bit like having plans for a modular building where parts can be selected and modified depending on needs.

    To illustrate - every cell in your body has all of the genes required to make an eye. These genes are only switched on in two locations. Geneticists have switched them on in multiple locations in fruit flies with interesting results.

    This is not evolution. Phenotypic plasticity is about development within a specific generation. Evolution is about changes in the genome between generations. However phenotypic plasticity may result in a selective pressure that drives evolution in a particular direction. For example let's say phenotypic plasticity builds a version of an insect body that favours a nocturnal lifestyle. This may result in other evolutionary changes over many generations. Colour optic genes may be lost for example.

    There is speculation in the article SBF linked that there may be a way for phenotypic plasticity to alter the genome more directly.

    There is no basis for SBF's assertions about "Dawkins' strident materialism and atheism". If other mechanisms of evolution are discovered the process will still be about chemical nuts and bolts. To bring atheism into the conversation is just bizarre.

  • Ruby456
    Ruby456

    here is the link shpeherdess and cofty

    This is nicely illustrated by a seven year field study of the predation of feral pigeon's that was conducted by Alberto Palleroni and his team of Harvard University
  • cofty
    cofty

    The evolution I described in the OP has absolutely nothing to do with phenotypic plasticity.

  • Ruby456
    Ruby456

    I don't see that sbf is being contrarian - he is disagreeing with cofty and providing evidence. His evidence broadens the subject of evolution and chimes with other evidence I have read which also disagrees with cofty's very narrow definition of evolution, genes the genome.

  • Ruby456
  • cofty
    cofty

    Ruby I don't have a narrow view of evolution, you are just echoing SBF.

    Later in this series I will include epigenetics and look at other forms of selection but ultimately there is no other way to evolve than to change the genome.

    You have linked to an article that contains only an index. How does that help?

  • Ruby456
    Ruby456

    change the genome? this is the problem - it is a problem of conception and definition - In a sense the genome does not have to change as for example in a mutation. However, irreversible and reversible adaptions can be absorbed into the genome.

    edit: I'd love to stay and talk - I do like talking to you and others on this thread, shepherdess, sbf etc but I have two appts and an essay to start planning

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