…Neanderthals did not contribute mitochondrial DNA to modern humans; Neanderthals are not our ancestors…
The original pre-visitation Earth inhabitants were probably the Cro-Magnon, Engis, Homo Erectus or Neanderthals. There could have been some other race altogether, but given the suppression of data in these subjects, it is doubtful if we will ever know the truth about our Earth ancestors. Recent findings seem to indicate that both Neanderthal and Cro-Magnon races were genetically interfered with and were the victims of hybridization.
It is known, however, that these Neanderthals suddenly vanished from the Earth for no known reason.