This is perhaps a bit of an odd question, but here goes. When physicists started investigating atomic nuclei, it turned out that protons and neutrons were composite, and the force binding them into nuclei was a complicated result of the strong interactions among their component quarks and gluons. Could it have turned out differently, without affecting the phenomena of everyday life? Could a universe very much like ours (at least to casual observation!) exist where instead protons and neutrons were elementary particles, and an elementary scalar field bound them in nuclei with a Yukawa force? (Edit: for clarification, I'm imagining that protons and neutrons in this scenario would be related in the same way as electrons and neutrinos, and the details of the electroweak interaction are the same as in our universe.)