I've yet to see any evidence that humans have ever evolved (ie, it's sci-fi to me, and poorly constructed at that), so no point in even arguing this. Yeah, the work could do great things (maybe), but you know... I'm 28 and I've had my idealism beat out of me and think resolutely it would be used as a weapon before anything else. And probably will be...
Back on topic:
I just read Seven Daughters of Eve which talks about how mitochondrial dna can be used to trace back common ancestors of humans (unfortunately lots of times from an evolutionary standpoint, but...). I think that at the very least the islander's blood would give a rough estimate of how long ago the PC tampered with us just by comparing variations with the isolated islanders.