re: #100 Blind Frog Belly White

There have been two attempts by ST series to explain this:

Preceding the Federation by hundreds of thousands of years there was a large empire that spread over much of the galaxy in which the Federation now occupies.

Secondly, long ago in the early period of the galaxy an extra-galactic civilization seeded our galaxy with amino acids that would form the basis of the evolution of life into similar forms.

A third explanation is the god-in-the-box solution, which was never formally presented but lays there like an open sore: The Q.