Genome and evolvability: layers that modify (Introduction)

by David Turell , Thursday, February 08, 2018, 18:40 (2276 days ago) @ dhw

QUOTE: Genome invading agents such a viruses and RNA-networks represent a very large and dynamic source of genetic novelty. They can co-operate, build communities, generate nucleotide sequences de novo and insert/delete them into host genetic content. Viruses and RNA-networks often remain as mobile genetic elements or similar ‚defectives’ and determine host genetic identities throughout all kingdoms including the virosphere. But inclusion of a transmissive viral biology differs fundamentally from conventional thinking in that it represents a vertical domain of life providing vast amounts of linked information not derived from direct ancestors.”

DAVID: The genome then is less of a pristine descending tree of common descent than one that has influences coming in from the outside of the tree working with previous developments and based on the past, pushing evolution into new directions. Could easily be the way God dabbles! Thus it looks like simple common descent, specifically linked entirely to the past, but really isn't. Darwin doesn't fit, but there is no way he could have imagined all these hidden influences which destroy his theory of mechanism.

dhw: By definition a novelty will provide information not derived from direct ancestors, but each novelty will still have to occur in existing organisms unless you believe in a God who creates every new organism from scratch. Cooperation was a major feature of Lynn Margulis’s interpretation of evolution, and it makes perfect sense that if an “invading agent” brings benefit to the host, the novelty will survive. The novelty is not “linked entirely to the past” – how could it be? – but evolution is a process by which existing organisms change into different organisms through innovation. The host provides the transition of descent from previous form to new. I agree yet again that Darwin’s mechanism of random mutations doesn’t work, but these “hidden influences” do not in any way undermine his theory of common descent. What you have called the "basic patterns" remain, and influences both hidden and open may determine what new forms they take.

Once again, we are in general agreement.