Discussions on the history and historiography of Australia's New England

Monday, June 12, 2017

Paleoanthropologists having fun - Almost Human, new discoveries from Jebel Irhoud

In “Almost Human,” the search for hominin fossils reads like an extreme sport. Written by Lee Berger with fellow paleoanthropologist John Hawks, the book documents with riveting intensity Berger’s lifelong fascination with fossil hunting and the contributions he has made to our understanding of human origins. Rachel Newcombe Washington Post
There is no doubt that paleoanthropologists are having fun at the present time. One sign of this is the release of Lee Berger and John Hawks' Almost Human. From Rachel Newcombe's review in the Washington Post it sounds like a rattling good yarn.
In contemporary paleoanthropological circles, Berger ..... is considered something of a maverick. He invites National Geographic to document his expeditions for social media, puts out calls on Facebook to invite scientists to join his teams and, rather than hoarding his finds so he alone can analyze them, makes replicas and photos of fossils available for other scientists to study. Rachel Newcombe
Berger may be a maverick, certainly he has drawn criticism from fellow professionals, but he is part of a new wave that is reshaping our fundamental understanding of the deep human past.

"The famous drawing of a linear and simplistic evolution from ape-like individual morphing to an upright modern human is anything but accurate." Renaud Joannes-Boyau

The latest in the string of recent discoveries exciting paleoanthropologists comes from the Jebel Irhoud site in
Morocco 100  some kilometers west of Marrakech. This site first  came to attention in 196o when a barite mining operation discovered a fossil skull. Subsequent excavations uncovered a range of hominin (early human) fossils but there were considerable difficulties in dating them accurately.

In 2004 an international team of scientists led by Jean-Jaques Hublin from the Max Planck Institute  for Evolutionary Anthropology in Germany and including Renaud Joannes-Boyau from Southern Cross University began a  new study of the site. They found 16 new human fossils, animal remains and a large number of African Middle Stone Age artifacts showing Levallois technology with a high proportion of retouched tools.

The rather starting results  have now been announced in two articles published in Nature.well summarised by two stories, one by Renaud Joannes-Boyau in The Conversation,  a second by Kate Wong in Scientific American.

The fossils have been classified as belonging to homo sapiens. They display our species slim "gracile" face as compared to the more robust face and elongated skull of the Neanderthals. However, there are differences in skull structure from today with a more elongated brain case, both longer and lower. In date terms, the remains have been dated to 300,000 years ago, adding 100,000 years to the earliest known date for homo sapiens.

In parallel with the two Nature articles on the latest Jebel Irhoud results, results have been released for a pre peer review formal publication study entitled Ancient genomes from southern Africa pushes modern human divergence beyond 260,000 years ago.This early release process allows  preliminary study results to be made available quickly; the formal peer review and publication process can take years.

This study examined the genomes of seven people from several different groups in Southern Africa who lived between 300 and 2,000 years ago. The results suggested that the different groups to which these individuals belonged diverged at least 260,000 years ago, implying that homo sapiens is at least this old.      

 I lack the technical expertise to properly evaluate the latest results. However, the conclusions as I see them are:
  • Homo sapiens emerged earlier and was more wide spread across Africa than previously realised, well before the 100,000 or so years ago date for the out-of-Africa migration
  • The evidence for overlap in time between various hominid species seems to be getting stronger all the time
  • The definition of just what constitutes homo sapiens among hominids has become very uncertain. I's all very messy if also intensely interesting! 
  • The need to understand the detail of constantly changing environments over long periods keeps growing. 


Johnb said...

We seem to be getting closer to matching the subjectively obvious to the scientifically established Jim. I would expect further discoveries in Australia and our near North to continue to add challenge to the original Out of Africa hypothesis and timeline. Primates are not exclusive to Africa and Geography itself is a variable over time that must have also had significant influence both in a Darwinian and Physical sense. Completely agree with your,bullet point as to the overlap of hominid sp..and I suspect inter-breeding to have promoted the emergence of the new and to have accelerated simple Darwinian selection. The Moroccan discoveries will also provide evidence for a much simpler route into Western Europe than the long slog from the East, the Atlantic coast even provides a highway and an immediately exploitable food resource on arrival. Very much a case of 'Watch this Space'.

Jim Belshaw said...

Definitely watch this space, Johnb! I'm still inclined to support out of Africa for homo sapiens sapiens, but... You may find this piece by John Hawks interesting - Features of the Grecian ape raise questions about early hominins http://johnhawks.net/weblog/fossils/miocene/graecopithecus/graecopithecus-fuss-2017.html. Everybody is getting into the claim game!

Johnb said...

Many thanks for pointing me tothe John Hawks weblog Jim, I have dutifully bookmarked it for ongoing reference.
I also found the Elephant story of interest and felt some of his words there need to be considered Jin the evolution of Homo Sapiens as we are. Quote The researchers found evidence that many of the different elephant and mammoth species had interbred. Straight-tusked elephants mated with both Asian elephants and woolly mammoths. And African savannah and forest elephants, who are known to interbreed today — hybrids of the two species live in some parts of the Democratic Republic of Congo and elsewhere — also seem to have interbred in the distant past. Palkopoulou hopes to work out when these interbreeding episodes happened. end quote. In reference to the Greek mandible fossil my immediate thoughts went to the discoveries in Georgia that are opening another page in our story. Out of Africa may remain the most favored option but discoveries are starting to give pause for thought as a more complex reality is being revealed.

Jim Belshaw said...

I find JH's material very interesting, Johnb, although I wish he would do more interpretive, overview stuff. I really feel the need for that.

I also wish that we had more easily available material on the pattern of environmental change over the last million or so years and especially during the Pleistocene. We really need that now. Anyway, I do.

I know from my Australian work that a knowledge of changing geography is critical to the interpretation of other evidence. I have still to find proper sea level maps that allow me to understand the detail so far as New England is concerned.

Johnb said...

This is where our geologist friend across at Northern Geology was so useful even though his forte was geological time. I was particularly interested in his article on the Orara River, the river that flows the wrong way. The geological story of the Clarance River catchment also impacts very much on the story of New England, much more so than the traditional catchments running off the tablelands to the coast.South of the Orara river.

Jim Belshaw said...

Rod has moved to Armidale. That plus the sad death of their daughter has had an understandable impact. I really would like Rod to write again. Perhaps time i encouraged him.certainly I would like to pluck his brains.

Rivers on both sides of the Tablelands first flow north!