I remember being taught that the MtDNA had to come from the mother, and her blood, through the umbilical cord, provided the mitochondria. If Dad is contributing this material, how is his mitochondria introduced?
This might be a window into an unexplored region of the Human genome...
The tail of the sperm contains mtDNA and if it enter the egg then there might be paternal mtDNA as well.
Could it be drug-induced mutation of genetic material that is passing more MtDNA to male children and less to the females? ....Could that explain the whole transgender trend over the past decade or so?