Tell me sir in what way is it falsifiable?
Darwin cited several possibilities that would be "fatal to his theory". Recall that he and his age were utterly ignorant of molecular biology, which we understand as the entire basis of genetics. It's very easy to imagine any number of ways that biological evolution could have been falsified with this new knowledge. If different groups of plants or animals had incompatible genetic coding, that would do it.
Of course, just the opposite occurred, with genetic sequencing providing a sort of microscope into the details of ancestral relationships, and so providing comprehensive and spectacular confirmation of evolutionary descent.