Knowing physics is roughly same every where in the universe, same rules of biology will apply elsewhere where if conditions meet, maybe earth is one of many conditions that can form life.
Within those rules are a lot of things that can get by under them. Take two points in earths history bound by the same physical laws and life can look dramatically different. You can think of it like how we all use the same microsoft word but that doesn’t lead to the same exact book being written independently twice or more often. The amount of permutations to be taken along the way is a countless number probably far larger than the number of habitable star systems in the universe.
