Owen Lovejoy has some theories which he is using to process the data from the spate of Ardipithecus ramidus papers. When it comes to the argument about social structure based on the anatomy of the extant remains I’m skeptical. I just recorded a diavlog with John Hawks which is 2/3 devoted to Ardi-issues (should be up Saturday), and he pointed out that Lovejoy has been laying out the case for a monogamous social structure for early hominins for years. This is why I’m not that surprised that some of the numbers he cites from the literature are off. He’s probably quoting older values, and hasn’t been tracking updates or revisions.