I don't understand this argument, as it would apply equally to all features of the theoretical LUCA
> No it won't. Different features would have different tolerance levels to > modifications. Yes, this "tolerance" is the second (hidden or implicit) principle I referred to. So you'd have to explain why the codon convention is so intolerant/invariant relative to the other features--it seems to me that either it is at an optimum or there is some big barrier holding it in place. And you'd have to explain this without invoking interchange of DNA, viruses, etc, as we're talking about a LUCA here, right? And you'll have to make sure that whatever reason you invoke cannot be applied to other features of this LUCA which are indeed seen to be variable. JPK ******************************************* Jacob Pearson Keller, PhD Looger Lab/HHMI Janelia Farms Research Campus 19700 Helix Dr, Ashburn, VA 20147 email: kell...@janelia.hhmi.org *******************************************
