The article is full of gross approximations and falsehoods. The author later states things like

That link lies in the fact that mitochondria are not just cellular batteries. Billions of years ago they were actually independent organisms. They are an example of how the human body is not entirely “human.”

and (quoting someone else):

“Until recently, science has basically ignored the fact that we are all walking around with two genomes in every cell,” Dowling says, “that of our own nuclear genome, and that of the mitochondria.”