Full Idea
We need twelve particles in the master equation of the standard model, but it is necessary to have only four to build a universe (up and down quarks, the electron and the electron neutrino (or lepton). The existence of the others is 'a bit of a mystery'.
Gist of Idea
Only four particles are needed for matter: up and down quark, electron, electron-neutrino
Source
Peter Watson (Convergence [2016], 11 'First Three')
Book Reference
Watson,Peter: 'Convergence' [Simon and Schuster 2016], p.262