Polygenism already
is established science.
In genetic terms, monogenism means that there was a time when there was a
population bottleneck with the size of 2, or, that there was a time when the
effective population size of humans was 2.
Past effective population size can be calculated from an analysis of genetic diversity of the present population. Basically, there are some statistical laws which govern how genes change (so-called
genetic drift) and they allow you to back-calculate what the human population would have to be in the past to get to the present state. Here is (one of many) technical paper which does that:
genome.cshlp.org/content/17/4/520.long
Here’s the important result: there is no evidence of any population bottleneck with the population size of 2. Nothing. Nada. The lowest estimate of a population bottleneck we have is 1200 and it is linked to the Toba catastrophe. Also, this is not a new development either: there are papers from at least 20 years ago discussing that. The evidence simply continues to mount.
Here is a quite understandable treatment of the subject written by a Catholic priest and a biologist:
3op.org/nicanor_austiaco_article.pdf
So yes, the claim made in
Humani Generis #37 has been falsified. With all the nasty consequences. Meaning, it appears that we have to throw out everything, starting from papal infallibility, through Orginal Sin and ending with Redemption. Or, as you prefer, the whole religion appears to collapse.
That said, it appears that the writer of Humani Generis #37
did leave us an escape hatch. The hatch is a essentially a technicality, so I’m not quite convinced that he did it on purpose; nevertheless; the hatch
is there. Make of this what you will.
The escape hatch works like this. The text in #37 says
it is in no way apparent how such an opinion [polygenism] can be reconciled [with faith]. So it doesn’t say that polygenism
cannot be objectively reconciled with faith; but that the
writer of Humani Generis
does not see how it can be reconciled. The implication is that
if someone can propose a theological reasoning which reconciles Christianity with polygenism
then the prohibition in #37 is void. See e.g this:
vox-nova.com/2011/02/11/moving-forward-with-polygenism/
Of course
how to do that technically
is no way apparent 
but there are some papers out there with different ideas, written by theologians wrestling with the problem. The very existence of these papers proves that – as minimum – the theologians believe that the problem is not unsolvable.
In my opinion, while Catholicism can indeed escape through that escape hatch, it will end up badly wounded. The problem is that #37 still contains a
definitive prohibition:
the faithful cannot embrace the notion… So even if someone finds a theological way to integrate polygenism into Christianity, we are still talking a major doctrinal revision. So one still has to (1) salvage papal infallibility and (2) explain what happened to the poor souls who were condemned to hell for believing in polygenism. Basically, it’s the Gallieo blunder all over again.
Fun times