Fossil 'not the missing link after all'

When Ida the fossil's discovery was announced, it was called "the link" that would reveal the earliest evolutionary roots of monkeys, apes and humans.

But experts protested that Ida was not even a close relative - and now a new analysis supports their reaction.

Erik Seiffert, of Stony Brook University in New York, says Ida is as far removed from the monkey-ape-human ancestry as a primate could be.

He and his colleagues compared 360 specific anatomical features of 117 living and extinct primate species to draw up a family tree. They report the results in today's issue of the journal Nature.

Ida is a skeleton of a 47-million-year-old cat-sized creature found in Germany. It starred in a book, 'The Link: Uncovering Our Earliest Ancestor'.

Ida represents a previously unknown primate species called Darwinius.

The scientists who formally announced the finding in May said they were not claiming Darwinius was a direct ancestor of monkeys, apes and humans.

They did argue that it belongs in the same major evolutionary grouping, and that it showed what an actual ancestor of that era might have looked like.

But the new analysis says Darwinius does not belong in the same primate category as monkeys, apes and humans. Instead, the analysis concluded, it falls into the other major grouping, which includes lemurs, and experts agreed.

Eric Sargis, an anthropology professor at Yale, said: "This is a rigorous analysis based on many features."

He said he found the argument of the Darwinius researchers unconvincing, so the new result came as no surprise.

It confirms what most scientists think, said David Begun, a paleoanthropologist at the University of Toronto.

Jorn Hurum of the Natural History Museum in Oslo, Norway, an author of the Ida paper, said he welcomed the new analysis.

Darwinius is an example of a group of primates called adapoids, and "we are happy to start the scientific discussion" about what Ida means for where adapoids fit on the primate family tree, he said.