Using neutron stars and primordial black holes to test theories of quantum gravity

Three observational tests of cosmological natural selection, a theory that follows from some hypotheses about quantum gravity, are described. If true, this theory explains the choices of the parameters of the standard model of particle physics. The first, the observation of a pulsar with mass greater than $2.5 M_\circ$, would cleanly refute the theory. The second and third, having to do with primordial black holes and early massive star formation, could do so given likely developments in the near future. However given present knowledge these arguments do not presently refute the theory. This shows that cosmological natural selection has not so far been refuted, in spite of being very vulnerable to falsification by possible observations.