What does the human face tell us about our evolution

Henryn recently posted a question asking which part of the human body is the most evolved. To see sabrinah's answer click here.

�

Meanwhile another feature of human evolution is causing a stir in the world of palaeontology: our flat faces. A 3.5 million year-old hominid skull unearthed in a small gully in Kenya may force scientists to re-examine the evolution of modern humans.

�

Q.� What is a hominid

A.� A human like creature that walked on two feet. Until now it was thought that there were only three groups of hominid: Homo (the genus from which modern humans eventually evolved), Paranthropus, presumed to be an evolutionary dead end and Australopithecus; thought to have given rise to Homo.

�

Q.� What has been found

A.� The skull, parts of the jaw and some teeth. The specimen has been assigned to a previously unknown hominid genus and species, Kenyanthropus platyops, which means 'flat faced human from Kenya.'

�

Q.� Why is Kenyanthropus causing such a stir

A.� Because it's the first hominid that's been found dating from 3 to 4 million years ago since Australopithecus afarensis was unearthed in 1974. Very few specimens exist for this crucial period when our ancestor should have been displaying less ape like and more human like features.

�

Humans and African ape lineages split between 5 and 10 million years ago. Until now Australopithecus afarensis was thought to be a species directly on the lineage from this split to modern humans. Now Kenyanthropus platyops may claim the title instead.

�

Q.� Why does Kenyanthropus platyops seem more likely to be our ancestor than Australopithecus afarensis

A.� The skull shows much more human like features than the relatively ape like Australopithecus afarensis. It has a less protruding jaw and more pronounced cheek bone, giving it a flat face. A flat face is one of a set of uniquely human features.

�

Logically, the oldest fossil displaying the most human like features will be our direct ancestor. Any other fossil will be classified as a mere distant relative.

�

Q.� So is Kenyanthropus platyops definitely a direct human ancestor

A.� The scientists are refusing to speculate too heavily and are struggling to sort out the relationship of various extinct hominids.

�

Has something in this article raised a question about human evolution for you Just click here to post it.

�

by Lisa Cardy