User blog comment:D.Ryan/As Sonbird is to Big Daddy as Elizabeth is to Little Sister/@comment-91.115.117.238-20130329153750

I'm sure the Andrew Ryan is not an alternate version of Booker because we know very much about ryans past and it differs greatly from anything that we know about booker. From my point of view Neither Elisabeth nor Columbia ever existed because in the end Elisabeth kills Booker and disapears herself so that there wont be a comstock in any reality anymore. So in the end Elisabeth grows up as Anna Dewitt together with her Father Booker without any powers (since there was never an accident with a tear) and had a normal life.

If Columbia existed the technology for vigors would also exist and so the discovery of the sea slug and the creation of adam eve and plasmids wouldn't be such a great deal. Of course vigors seem to have less posibilites concerning genetical manipulation but they have far less side effects than plasmids. In fact no one in columbia seems to suffer from any problems with vigors even though they use them frequently.

Another indicator for the non existance of columbia is its absence during wwII columbia even attacked the boxers and with their superior quantum and vigor technology they would be easily able to attack nazi germany or communist russia bof enemys of the Columbian way of life.

I think the similaritys between big daddy and songbird as well as many other things are there to so that Bio Inf still feels like a real Bioshock with the recurring motives of Political and economical fanatics, decadent utopian societes, and the power and danger of technologies.