Dark matter obeys gravity after all — could that rule out a 5th fundamental force in the universe?

Scientists have discovered that dark matter, the universe's most mysterious "stuff," obeys gravity on vast cosmological scales. This could help to dismiss the possibility of a fifth fundamental force of nature — but even if not, it certainly puts restraints on that potential force's strength.

It's long been known that "everyday matter" is made up of atoms, which are, in turn, composed of protons, neutrons and electrons. We also know that these particles fall in line with the known fundamental forces of nature: electromagnetism, gravity, the strong nuclear force and the weak nuclear force. However, what has been less clear is whether dark matter obeys these same four forces. Indeed, one of the reasons dark matter is so puzzling is that it doesn't seem to act in conjunction with light, or e