But Tim White, a prominent evolutionary biologist at the University of California Berkeley, just isn't buying this new species idea, nor is Milford Wolpoff, a longtime professor of anthropology at the University of Michigan. They said the Leakeys are making too big a jump from too little evidence.
White said it's similar to someone looking at the jaw of a female gymnast in the Olympics, the jaw of a male shot-putter, ignoring the faces in the crowd and deciding the shot-putter and gymnast have to be a different species.
Eric Delson, a paleoanthropology professor at Lehman College in New York, said he buys the Leakeys' study, but added: "There's no question that it's not definite." He said it won't convince doubters until fossils of both sexes of both non- erectus species are found.
"It's a messy time period," Delson said.
Seth Borenstein can be followed at http://twitter.com/borenbears