Interestingly enough, there is some new evidence from the genetic sciences that it is at least possible for all human persons to have come from an original homo sapien pair; at least genetically. I don’t understand these issues that well, because there is a lot of modeling and also a lot of math involved, but there was a long series of exchanges between BioLogos advocates and ID advocates on this last November. Some of the folks involved in that were Dennis Venemma from BioLogos, Richard Buggs, Joshua Swamidass, and Ann Gauger (from the Discovery Institute). The issue had to do with a claim that was made in Venema and Scot Mcknight’s book on Adam. As far as I know, right now things stand that there could have been an original genetic pair, but that pair would have had to exist, at the latest, around 500 million years ago or earlier.
Here is an article relating to that conversation of several thousand posts between Venema, Buggs, Swamidass, et al.
Note, I’m not saying that this is the view I hold (i.e. that there was an original pair some 500 million years ago that just was Adam and Eve), but the backing away from the claim that there could only have been a population of at least 1000 or more, I think does illuminate how scientific results are never really as fixed as we think they are. Who knows where the “consensus” will be in 50 years?
Also, I think that the argument from common design over common descent is also getting stronger; so that the genetic similarities between us and apes, gorillas and chimpanzees might very well be better explained not by ancestry, but by common design plan. Here is a good video on that: