"Overall, our findings confirm the human family tree is more complicated than we think it is," Dr. Bohlender said. "For example, other archaic populations are likely to have existed, like the Denisovans, who we didn't know about except through genetics."
More complex? That's an easy bet to take. Whenever we think we know something, new evidence comes out to show we know but a fraction. I tend to preface science discussions by saying "Well, the current thinking is ..."