Studies of mtDNA had suggested a timing for the "Out of Africa" exodus of 60-70, 000 years ago.

BBC: Humans 'left Africa much earlier'

Therefore the amount of mtDNA actually recoverable by PCR in this experiment may well have been minimal.

FORBES: Big Study Linking Chronic Fatigue To Virus May Be Fatally Flawed

The researchers analysed mtDNA sequences in 211 dingoes and compared them to a world-wide sample of 676 dogs.

BBC: NEWS | Science/Nature | Dingo's origins tracked by DNA

Although both sons and daughters inherit mtDNA from their mothers, only daughters can pass mitochondrial DNA to their children.

CNN: DNA provides clues to family's African heritage

Indeed studies have demonstrated that such cell lines are either depleted of mtDNA (12) or that the mitochondrial genome is highly mutated (13).

FORBES: Big Study Linking Chronic Fatigue To Virus May Be Fatally Flawed

Next we turn to the section of the study where the authors test the ability of their PCR assays (IAP and mtDNA) to detect mouse DNA in mouse cell lines.

FORBES: Big Study Linking Chronic Fatigue To Virus May Be Fatally Flawed

Similarly the claim that IAP is superior to , or even as reliable , as mtDNA PCR in vivo is not supported by the data cited as alternative explanations for the findings are readily available.

FORBES: Big Study Linking Chronic Fatigue To Virus May Be Fatally Flawed