New Jawbone Fills Gaps, Raises Questions

A group working in the Afar Triangle has discovered a mandibular fragment with associated teeth that show strong affinities to early Homo.

The catch is that the provisional date for this specimen is 2.8 million years. Writes Pallab Ghosh for the BBC:

The head of the research team told BBC News that the find gives the first insight into "the most important transitions in human evolution".

"This is the most important transition in human evolution”

Prof Brian Villmoare University of Nevada

Prof Brian Villmoare of the University of Nevada in Las Vegas said the discovery makes a clear link between an iconic 3.2 million-year-old hominin (human-like primate) discovered in the same area in 1974, called "Lucy".

Could Lucy's kind - which belonged to the species Australopithecus afarensis - have evolved into the very first primitive humans?

"That's what we are arguing," said Prof Villmoare.

This find in the north of the continent strains, almost to the breaking point, the argument that Australopithecus sediba is the best candidate for being ancestral to early Homo. That find came from a cave in South Africa and, up to this point, all of the respective species of Australopithecus have been fairly tightly geographically restricted in their home ranges. The distinct possibility exists that only A. afarensis is ancestral and ALL other australopithecines went extinct, but we will have to wait for considerably more comparative studies on the morphology of the jaw to make any sort of rudimentary arguments along those lines.