For an analogous case, consider Lee Smolin's "Life of the Cosmos" hypothesis. That posits natural selection between universes - and black holes as the birth canal for new universes.

That seems literally incredible - since black holes have no insides. However, the rest of the logic of Smolin's hypothesis does not depend critically on the origin of the new universes - so if you replace "black holes" with "basement universes" the hypothesis becomes much more credible.