AS ONE of the most significant primate fossil finds ever made, Ida will be hailed by some as “the missing link” in our evolutionary history.
But is that really true? Well, yes and no.
The phrase usually refers to the creature that links us to the apes, in particular the common ancestor of chimpanzees and humans.
At 47 million years old, Ida – or Darwinius masillaeto use her formal name – is much more ancient than that.
But she is undoubtedly a very significant link in the primate lineage and the evidence from her extraordinarily well-preserved skeleton points to her being a very early member of our own primate line.
The fossil evidence of primate evolutionary history is sparsely populated – more missing than link. So almost any major primate fossil at a significant point in our ancestral line could be referred to by that overused phrase.
Also, filling the gap is not the end of the story. “Every time you find a link that once was missing, you find two more, you’ve created two more that are missing. So it’s never going to be a complete chain,” said Sir David Attenborough.
Jorn Hurum, at the University of Oslo, the scientist who led the team that studied the fossil, is relaxed about the phrase.
“Why not? I think we could use that phrase for this kind of specimen,” he said. “[People] have a feeling that if something is important it is a missing link.”
However, in the paper published in PLoS ONEfrom the Public Library of Science on the fossil, he is more circumspect.
" Darwinius masillaeis important in being exceptionally well-preserved and providing a much more complete understanding of the paleobiology of an Eocene primate than was available in the past . . . [the species] could represent a stem group from which later anthropoid primates evolved [the line leading to humans], but we are not advocating this here."
The paper’s scientific reviewers asked that they tone down their original claims that the fossil was on the human evolutionary line. – (Guardian service)