My guess is that their legal system just hasn't caught up with DNA testing -- the only way to dtermine bio dad
That's kind of what I thought...but you'd think that DNA testing has been around long enough at this point to have been used by someone who needed it to establish or refute paternity for one reason or another.
That's what made me wonder if there was some other reason they held to a legal definition of paternation rather than a biological one.