Self Identification and the Residual Self Image

I want to start this discussion to generate possible outcomes. Where does unique identity start and where does it end? How much can an individual adapt to survive, and when do they lose their uniqueness? I think of films like the Matrix, Total Recall, any other sci-fi inspirations where one can change existence to adapt to their environment, whether by choice or unknown to the event happening . Games such as Deus Ex are a great example of modifications to the self, furthering the self identity as a dependent to whatever technology is acquired. Now, let's extend this to other types of identity, such as gender. Is the self alignment to male or female a natural biotic process, or a pre-conceived notion, a gray area if you will, only upheld by society. Where do we draw the line at what is acceptable, and should any line be drawn at all? As humanity moves forward, what will the final image be?