From the Celestials’ experiments on this species emerged three branches of Skrulls: the Prime, the Deviants and the Eternals.
The Deviant Skrulls would then split into two groups: the modern Skrulls and the Dire Wraiths.
Because the Deviant Skrulls were able to shapeshift, they emerged victorious in the conflict with the other two races, leaving only an Eternal Skrull and a Prime Skrull alive when all was said and done.
Porto-humanity wasn’t the only species that the Celestials experimented on.