Again: this is speculative. But, it's fun.
Theoretical physicists have suggested for years that a universe might give rise to other universes. See, for example,
The Self-Reproducing Inflationary Universe, Andrei Linde, Scientific American, November 1994 pp. 48-55Recently Dr. Lee Smolin suggested an interesting variation on this. Suppose, he said, a black hole can cause a new universe to bud off. Suppose that the laws of physics in the new universe are not identical to the laws in the parent universe. Specifically, suppose that the fundamental constants change a little.
Smolin suggests that a universe with more black holes has more "children". So, a strange sort of evolution could occur. The process would "breed" for productive universes, until the most productive kind was found.
Now, Smolin didn't just throw this out as a bare idea. He's spent a lot of time asking the question: what would the "most productive" universe look like? He thinks that it would be exactly what we see around us. He thinks that the "fine tuned" fundamental constants have in fact been fine tuned - not to allow human life, but to give the very best black holes. Carbon, he says, is here because it helps transfer heat inside protostars.
Is this stuff true? Well, I'm not qualified to judge, and the idea is still pretty new. But right or wrong, it does state a reason for the universe to be "fine tuned". For more details:
New Scientist, 24 May 1997, pp. 38-41
The Life of the Cosmos, L. Smolin, Oxford University Press 1997