New Fossils and Our Understanding of Human Evolution

By Mike Dunford

August 9, 2007 13:31 MST

There [are](http://www.nature.com/news/2007/070806/full/070806-5.html) [a lot](http://abc.net.au/news/stories/2007/08/09/2001083.htm?section=world) [of news](http://www.latimes.com/news/science/la-sci-skull9aug09,1,754351.story?coll=la-news-science&ctrack=1&cset=true) [articles](http://news.google.com/news/url?sa=t&ct=:ePkh8BM9EwLbwQq0w4AFYguQXQJh47LHSOBcZfnSfzf327eaOPWf-X5VFQB1QBDR/4-2-2&fp=46bb89bb53530556&ei=O0u7RraHIIeUrgOnsoWtBA&url=http%3A//www.nytimes.com/2007/08/09/science/09fossil.html%3Fref%3Dworld&cid=1119132016) out today that feature some just-published research on early human research. The research itself - [a paper in the journal ](http://www.nature.com/nature/journal/v448/n7154/full/nature05986.html)_[Nature](http://www.nature.com/nature/journal/v448/n7154/full/nature05986.html)_ by a team of scientists including the mother-daughter combinationon of Meave and Louise Leakey- features two partial skulls found east of Lake Turkana in Kenya. One of the fossils, a cranial dome that's been identified as belonging to a young _Homo erectus_, has been dated at about 1.55 million years old. The other, a partial upper jaw from _Homo habilis_, is about 100,000 years younger (1.44 million years old). This shows that the two species overlapped in time, and that both may have occupied at least some of the same places during the period of overlap.

In the media, this is being reported as a find that "casts doubt on the origins of man" ([Australian Broadcasting Corporation](http://abc.net.au/news/stories/2007/08/09/2001083.htm?section=world)), "eliminat

$es$ one reputed ancestor from the human lineage" ([LA Times](http://www.latimes.com/news/science/la-sci-skull9aug09,1,754351.story?coll=la-news-science&ctrack=1&cset=true)), "challenges standard evolution theory" ([Kansas City Star](http://www.kansascity.com/105/story/224364.html)), and "shows us just how utterly ignorant we were about where we came from" (OK, I made that one up). That's a pretty cool feat for two chunks of bone - if you believe the press reports, anyway. Of course, the press has been known to occasionally blow new research out of proportion every now and then, so it's probably worth taking a closer look at what's actually being claimed for these fossils.