Ancestral Bushwhack: Hominid tree gets trimmed twice

Many anthropologists suspect that hominids, ancient members of the human evolutionary family, branched into as many as 20 different now-extinct species over roughly the past 6 million years. At scientific meetings in Phoenix last week, two skeptical researchers took different approaches to pruning this species-laden scenario.

Their handiwork expands debate over how to identify hominid species in the fossil record.