Look at it objectively, from the perspective of a third person. Would they think G2 is G1? Yes, and G2 would carry on like G1 would have done, if he was still around. I am not implying there has been a transfer of 'self' You are just information that has been copied. The idea of self is an emergent property of of all the experiences we've had, embedded in the molecular arrangements of our brain. The one recurring thing, I find when studying the ontology of life and matters relating to it, is you have to get to grips with is the idea of emergence.