  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.
