There are several reports in the media about a third hominin group besides Denisovans and Neanderthals, and how they contributed to Melanesians. Science News has a sober summary of it all.
Several people have asked me on email and Twitter about this, and I told them to ignore it. The reason I say this is that I was in the room when the presentation was given, and it was clear people were having a hard time following what was going on. Afterward several pretty intelligent statistical human geneticists expressed great confusion.
A few things to take away. First, it was a presentation at a conference. One can’t expect very novel findings to be understood easily in a 15-30 minute talk. Wait for the preprint at least. Second, this was a presentation at a conference. A lot of presentations don’t pan out. If it’s a really surprising theoretical or interpretative finding, as opposed to sequencing a new species (an empirical result), generally I don’t pay close attention. A lot of time the reason that no one else has stumbled onto the surprising results is that they are wrong, or trivial upon further inspection.
Finally, there are complexities of human history we don’t have a good grasp on. There may indeed be other hominins which contributed to the human gene pool to the point of detectable admixture. I think it is likely. But it is a different thing to have specified all the details.
Basically, I wish the press would set a higher bar for presenting on new results from conferences. It’s not even that it’s not been peer reviewed. Often the results are provisional, and they don’t end up turning into the paper that’s promised.