MIT physicists have showed that universes quite different from ours still have elements similar to carbon, hydrogen, and oxygen, and could therefore evolve life forms quite similar to us, even when the masses of elementary particles called quarks are dramatically altered.

Some physicists have theorized that only universes in which the laws of physics are “just so” could support life, and that if things were even a little bit different from our world, intelligent life would be impossible. In that case, our physical laws might be explained by the “anthropic_principle,” meaning that they are as they are because if they were otherwise, no one would be around to notice them.

Jaffe and his collaborators felt that this proposed anthropic explanation should be subjected to more careful scrutiny, so they decided to explore whether universes with different physical laws could support life. Unlike most other studies, in which varying only one constant usually produces an inhospitable universe, they examined more than one constant.

Sources: Life beyond our universe and Looking for Life in the Multiverse