DNA findings may point to new human ancestor

So the Siberian species may be new, although the scientists cautioned that they are not ready to make that assertion yet.

Other specialists agreed that while the Siberian species may be new, the case is far from proven.

“We really don’t know,’’ said Ian Tattersall of the American Museum of Natural History in New York, who was not involved in the new research.

But “the human family tree has got a lot of branchings. It’s entirely plausible there are a lot of branches out there we don’t know about.’’

The discovery “is like many new finds,’’ said Eric Delson of Lehman College of the City University of New York, who did not participate in the new work.

“You say, ‘I think this is different, but I’m not sure.’ And then you look for more material, and you try to make better comparisons.’’

The researchers, who say the Siberian species is not a direct ancestor of modern-day people, hope further genetic analysis will show whether it is a new species.

Some specialists are skeptical about whether such analysis will resolve that.

In any case, the finding emphasizes that quite unlike the present day, anatomically modern humans have often lived alongside their evolutionary relatives, one specialist said.

“We weren’t alone,’’ said Todd Disotell of New York University, who was familiar with the new work.

“When we became modern, we didn’t instantly replace everybody. There were other guys running around who survived quite well until very, very recently.’’

The new work was published online yesterday by the journal Nature.