Full Idea
It seems essential that you come from your gametes. Suppose (for reductio) that I come from Nixon's actual gametes. Now add my actual gametes to that possible world, and suppose they become an adult. Which has the stronger title to be me?
Clarification
'gametes' are sperm and egg
Gist of Idea
Suppose a world where I'm from different gametes; add my gametes; which one is more me?
Source
Colin McGinn (On the Necessity of Origin [1976], p.132), quoted by Nathan Salmon - Reference and Essence (1st edn) 7.25.5
Book Reference
Salmon,Nathan: 'Reference and Essence (2nd ed)' [Prometheus 2005], p.209
A Reaction
[See Nathan Salmon 1981:209] Feels like the Ship of Theseus. You say 'that's Theseus Ship', until the rival ship appears around the headland. Confusion. If Nixon's gametes can produce McGinn, the second gametes could produce a Nixon! Then what?