Many skeletal remains of humans that lived before Adam have been discovered. This is an undeniable truth. Beware of the ramifications of denial, Exodus 20:16. The mitochondrial DNA of one such find was inconsistent with all other people on Earth. It makes sense that some of the remains of humans that predated biblical Eve would have had different mitochondrial DNA than modern humans- some but not all. There would likely have been at least three mitochondrial DNA strains from the origin of Homines sapientes (ancient humans). Some sources suggest that even fewer than three mating pairs are essential to a viable population.4
4 Mack, Steve, Genetics, Molecular and Cell Biology, Children’s Hospital
However, the traces of the so-called mitochondrial Eve from over 140 thousand years ago will show up even in Noah’s descendants (us) since Noah and his sons probably had wives outside the Adam and Eve bloodline. This is why geneticists using their modern findings project back to a mitochondrial Eve from about 140 thousand years ago. There is no evidence against literal biblical Genesis in mitochondrial findings, only support.