Loading ...
Sorry, an error occurred while loading the content.

14652Candid Admissions

Expand Messages
  • Paul
    Jul 21, 2005
    • 0 Attachment
      Paul: Here is an article about the inability of
      critics to overcome objections based on irreducible
      complexity without resorting to just so stories based
      on faith that suitable mechanisms will be found.


      From the article:

      'Origin of genomic regulatory systems'

      "The nature and degree of gene expression is commonly
      governed by a tightly intertwined set of regulatory
      elements found on the DNA molecule. How is such a
      concert of regulatory elements supposed to have
      evolved as a unit? The scenario invoked has a distinct
      flavour of storytelling:

      ‘Advantageous substitutions in regulatory elements
      caused by genetic factors are most interesting. They
      must be responsible for morphological evolution as
      discussed before. When a new chain of gene expression
      patterns for transcription factors and signal
      transduction elements is appearing, many advantageous
      mutations are thought to occur simultaneously at the
      loci participating in the chain. This process is
      called “recruitment” or “cooption” by developmental

      How such a chain originates is a very difficult
      problem, i.e., a module of interacting gene loci would
      have to be constantly tested by natural selection
      under various genetic and external factors. On very
      rare occasions, while wandering via mutation and drift
      under available transcription factors, a module might
      find its place in a larger gene regulation network.
      Then positive selection may work on the regulatory
      elements of the module loci’3 [emphasis added]."

      Paul: Storytelling indeed. Backing up the stories
      with solid evidence is a good deal more difficult.
      Cliff has raised the point that in his view evolution
      was not characterized by gradualism or at least not so
      at all times. Even if you assume this to be true
      where is the evidence that a step by step process
      (gradual or sudden) lead to regulatory systems that
      are ubiquitous in organisms?