Universes may have natural selection, meaning they create other universes and evolve like living things.

Inflation universes – The Big Bang, a patch of ordinary space that contains no matter but a ton of energy that appeared in a different type of space called the false vacuum. It then grew like an expanding bubble which birthed our universe. If this is true then the false vacuum should experience a kind of inflation in which it accelerates its expansion at a incredibly fast speed. Meanwhile other bubble universes of true vacuum can appear within it, this universe would be different from our universe which appeared 13.8 billion years ago, it would be constant. Inflation multiverse relieves us of the need to choose or find a “Theory of Everything” as if this is true then parallel universes have been popping up in an inflating false vacuum for billions of years, so each could have different physical laws, determined by one of these solutions is the string theory, if true then it could explain why our universe seems FINE TUNED to values needed for life.
There is not yet an answer of why our universe seems fine tuned to our needs. If used as a theory, expect someone to use god as an excuse for the fine tuning.

COSMIC NATURAL SELECTION
Universes may have natural selection, meaning they create other universes and evolve like living things. Example, a black hole occurs when a huge star collapses under it’s own gravitation pull, which crushes all its atoms together until they reach infinite density. Stephen Hawking and Roger Penrose in the 1960S pointed out that this collapse is like a miniature BIG BANG in reverse. If this is true then a black hole could become a big bang which would spawn a entire new universe within itself. The resulting universe would be different from ours, it may have different physical properties than the one that made the black hole, this resembles a genetic mutation of sorts, like a new baby organism is different from its parents. If a baby universe has different physical laws that permit the formation of stars, atoms and life then it will also contain black holes, which means it could create more universes that have black holes inevitably creating universes in which more black holes are common than those without black holes, that cannot reproduce. Our universe then doesnt have to be the product of pure chance, if a fine tuned universe that contained life arose at random, surrounded by universes that arent fine tuned, then Cosmic Natural Selection would mean that fine tuned universes kept being produced thus making it impossible common phenomena. 1 BIG ADVANTAGE! IT CAN BE TESTED! If this theory is correct then our universe should be suited to making black holes.

THE BRANE MULTIVERSE THEORY
First intimation of hidden dimensions began with theoretically physicist Theodor Kaluza’s work. In 1921 in a newspaper he showed that by adding an extra dimension to Einsteins theory of general relativity he could obtain an extra equation that seemed to predict the existence of light. This was cool and all but wheres the extra dimension? Swedish physicist Oskar Klein gave an answer in 1926, he was thinking that the mysterious fifth dimension was curled up into a extremely small distance, about a billion-trillion-trillionth of a centimeter. Physicists have taken these ideas much further into the String Theory this seeks to explain fundamental particles such as vibrations of smaller entities called strings. When the String Theory was developed in the 1980S, we found out it could only work if there were extra dimensions. In the modern version of the string theory, also known as the M-THEORY there are up to 7 hidden dimensions. What’s interesting though us that these dimensions may not be compact after all, they can be extended regions called the branes which is short for membranes, which may be multi dimensional. A brane could be a perfect hiding spot for an entire universe; the M-THEORY proposes a multiverse of branes of various dimensions, coexisting rather like a stack of papers. If true then there should be a new class of particles called Kaluza-Klein particles. In theory we can make them in a particle accelerator like the Large Hadron Collider. These particles would have distinctive signatures, because some of their momentum is carried in the hidden dimensions. These “brane” worlds would remain separate from each other as forces like gravity do not pass between them but if they were to collide, the results could be monumental. Such a collision could have created our own big bang. It also has been proposed that gravity might leak between these branes which would explain why gravity is so weak compared to the other fundamental forces.