Different in degree or kind (Introduction)

by dhw, Saturday, December 21, 2013, 14:16 (3779 days ago) @ David Turell

dhw: But convergence entails variations on the same form ... which means genomes in different places respond in similar but often NOT identical ways to similar environmental demands. Doesn't this suggest individual responses rather than a universal programme handed down by the first living cells?
DAVID: Wrong interpretation. You need to look up the term convergence as used in evolution-speak lingo and jargon: The development of an organ with the same purpose but with an entirely different design. I.e., six types of eyes.-There is no contradiction here, except that the distinction between convergent and parallel evolution is sometimes blurred (unrelated desert plants on different continents often have similar forms of leaf, and that is also called convergence). If organisms respond to similar environmental conditions with six different types of eyes, I would suggest that this points to individual responses rather than a universal programme handed down from the first cells.-dhw: As our next exchange clearly demonstrates, you cannot find proof beyond a reasonable doubt.
DAVID: I have found proof beyond reasonable doubt for me. Adler found it for him. And there are many others.-The expression is normally used in a legal context, where the quest is for some kind of objective truth, and so of course that is the impression arising from your claim ... especially when you say it's based on science, which is supposed to be our most objective approach to truth. -DAVID: I don't know God's exact plan when it seems he started evolution and it turned out like a confusing bush of organisms.
dhw: So maybe his plan was not what you thought it was.
DAVID: Your problem is your misinterpretation of convergence, a major point Conway Morris makes. There are many organs life invents for one purpose but they are all different in design, making the point that life as designed in the beginning is very inventive, which is why the higgledy-piggeldy bush appeared. Accept that life is very experimental and much of my reasoning falls into plae.
I am all in favour of the view that evolution is a history of experimentation. That is why, in my opinion, your hypothesis that all innovations were preprogrammed in the very first cells (apart from when God dabbled) makes your reasoning fall out of place. Experimentation and what you call "a confusing bush of organisms" do not fit in with the precise planning advocated by your anthropocentric view of evolution, or with your insistence that cells and cell communities are mere automatons obeying your God's pre-given instructions. You can't have it both ways.