If you want to examine something from a text (such as a geneology), but there's no direct way to test it, the next best thing is to look at the text as a whole, and to test to see if what it says is true. For example, lets say you have a history book, and it tells about Joan of Arc, but you have no body to examine, you look at what she did, and then you look at examples from history, and see if they line up with what the text says.
Basically, see if it lines up with reality.
So in the case of the Bible, we look at what it says as a whole, for example, it says that egypt fell and that a semitic people left around that time, and we see that (per the Ipuwer Papyrus) this very similar to what we see in reality, and another example are cities, coinage, etc.
Taken as a whole, the Bible has been largely proven correct, at least as far as what can be proven scientifically/archaeologically, etc.