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Archived Comments for: Beyond Darwin: evolvability and the generation of novelty

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  1. The differentiation tree as a source of novelty and evolvability

    Richard Gordon, Gulf Specimen Marine Laboratory

    14 November 2013

    Dear Marc,

    You suggest that: “One [approach] is to look at development - embryology - …to try and understand how things might have changed, what was the underlying nature of the change. And not just what are the genetic differences…. We want to explain big things….” I didn’t use the word “evolvability” in Gordon (1999), but nevertheless proposed a model that places much of the origin of novelty in embryonic differentiation:

    “Proposition 69: a major step in the evolution of multicellular organisms was the ability to generate the next cell state splitter and accompanying differentiation triggers and commitment signal, i.e., the invention of continuing differentiation with postponed terminal differentiation….

    Proposition 70: the evolution of continuing differentiation coincided with the ability to duplicate terminal branches of the differentiation tree….

    In duplication of terminal branches of the differentiation tree, novelty comes not so much from the opportunities for new proteins, as from the opportunities for new tissues.”

    The initial duplication mutation is likely to produce one of your “non-lethal phenotypic changes”, and a bit of coevolution could iron out minor problems (Figures 24-26). You might want to have a look at it. Thanks.

    Yours, -Dick Gordon

    Gordon, R. (1999). The Hierarchical Genome and Differentiation Waves: Novel Unification of Development, Genetics and Evolution. Singapore & London, World Scientific & Imperial College Press.

    Competing interests

    None declared