According to the new theory, chimps and humans shared a common apelike ancestor much more recently than was thought. Furthermore, when the two emerging species split from each other, it was not a clean break. Some members of the two groups seem to have interbred about 1.2 million years after they first diverged — before going their separate ways for good.
If this theory proves correct, it will mean modern people are descended from something akin to chimp-human hybrids. That is a new idea, and it challenges the prevailing view that hybrids tend to die out.
It also strongly suggests that some of the oldest bones of "proto-humans" — including the 7 million-year-old Toumai skull unearthed in Chad in 2001 — may have belonged to a line of non-hybrids that died out, and were not human ancestors at all.