Terry:
Good question! We know that according to the Gospel Judas was appointed an Apostle by Jesus. After Jesus death and ascension, the book of Acts states that remaining 11 Apostles "cast lots" to decided between 2 possible replacements for Judas. Matthias was appointed as Judas' replacement.
All Bishops in the Catholic Church can trace their succession back to the 12 Apostles of Act chapter 1. The concept of the "Governing Body" is new even to the Watchtower relatively speaking. The 8 members of the Governing Body cannot trace their lineage back to the 12 Apostles. They can only trace their lineage back a few decades when the whole concept was created.