This got me to thinking about some relatively recent developments in our society--sperm banks and women donating eggs to other women in order to conceive. I think in both cases one could argue that the "biological parents" might be the donors. However, is any record kept of who these people are? Does the birth certificate indicate that John Doe donated the sperm; but the mother, Mary Jones, husband was Tom Jones. I am not sure; but am guessing it doesn't. With the gaining popularity of DNA testing, one can imagine an adult 20 years from now tracing their family tree through both digital records and DNA coming up with some questions, especially if their parents didn't tell the person he/she had a donor father or mother. How does one distinguish between this situation and an illegitimate or adopted child?I guess my first impression is that essentially the situations posited are no different than the current and past issues created by adoption where the adoptive parents never disclosed the process of adoption to the adopted child. I have heard dozens of stories from patrons at the Mesa FamilySearch Library over the years how they "discovered" that they were adopted late in their life. In those situations, nearly all of the current genealogy programs provide for optional parent-child relationships: adoptive, guardianship, grandparents caring for the child, foster parents etc. I have also raised the issue that our standard pedigree chart view of families obscures many cultural and social family relationships such as God Parents and other similar relationships.
The answer is simple, we handle these situations in the same way we have always handled adoptions and illegitimate or out-of-wedlock children; by noting the relationships and identifying the participants when they are known. I have stated in the past that finding an ancestor born out-of-wedlock may constitute a valid end-of-line situation if there is no information about the identity of the father or the mother or both. In short, I don't see the issues as creating any new situations that haven't already been addressed by genealogists many times in the past.