And 'gene duplication' and 'regulatory gene modification' produces only freaks that would be eliminated from the population, not new more fit creatures.This statement is trivially false.
But please, if you disagree, explain clearly to me how a gene duplication event, independent of gene product or expression level, will always lead to a reduction in fitness.
Here's where this started as support for the discussion of 'leg development'. The process of developing novel features through gene duplication and/or modification of regulatory genes has been reproduced in the lab. Please provide a relevant example where this did not result in a freak. No polyploidy in plants please. That wouldn't be relevant.