I am an experienced DNA analyst and I have not heard of morphing. The possible explanation exists that YSTR kits are far more sensitive to Y (male) DNA than regular STR kits and can pick up the male DNA contribution when STR kits cannot. That is what makes them useful.
Alot of female DNA can mask the YSTR, or male DNA and that is why we use YSTR markers/kits. I have seen it numerous times. It doesnt' mean that the STR profile is wrong, it just is picking up at a differnt level and looking at different markers than the YSTR kit is. You can have tons of female DNA in a YSTR sample, and it picks out only male DNA, because it is amplifiying markers of the Y chromosome, only males have. Does that help?
