Anthropology.net

I don’t know who this is worse for, the editors & reviewers over at Nature or the authors of the article who can’t tell the difference between crocodile teeth markings and stone tool modification, nor raise the possibility. The paper, “Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia,” very confidently proclaims unambiguous evidence for,

“stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access.”

Butchered by early humans or eaten by crocodiles? Image: David DeGusta

Given that the said rib fragment, DIK-55-2, came from a prehistoric lacustrine site. These markings could have been produced by crocodiles. Crocs, if you aren’t aware of (ahem editors and publishing group) are very abundant in the Rift Valley — both currently and prehistorically. On top of that, crocs like to eat meat and scavenge. Yes its true, they are carnivores. Australopithecines were at most ominivores, with wide based teeth useful in grinding tubers and nuts. Crocs have more meat shearing, bone crushing teeth than 3.39 million year old stone tools, which there are none of at the moment.

Given that there really isn’t an archaeological record for Australopithecine tools, I’ll take a gander and say crocs like to eat meat and scavenge more effectively than A. afarensis could make and use said tools to butcher a large ungulate. They have been on this Earth for roughly 197 million years more than hominins have and they are really good at what they do… Again, probably better than a species of hominins who did not live in the Stone Age. It is just as likely (if not more) that the markings were produced by crocodiles just given the ecological context.

Now just how different at cut marks from crocodile teeth marks? David DeGusta, from Stanford University, compared and contrasted the two different markings using images from Njau and Blumenchine (2006) paper titled, “A diagnosis of crocodile feeding traces on larger mammal bone, with fossil examples from the Plio-Pleistocene Olduvai Basin, Tanzania,” to those published in the current Nature article. I’ve inserted DeGusta’s image into this post on right for your own inspection. DeGusta was also on Science Friday, discussing this possibility, with one of the article’s authors, Zeresenay Alemseged. What do you think? Do they look completely different or similar? Seriously, I am asking you to comment. I’d like to know what you see.

Personally I don’t see much of a difference. I agree that stone tools marks are more V shaped, while croc teeth are more pitted/rounded. But take this into light: tool use, especially butchery, is a very human behavioral trait. In their search to attribute this human behavior to a primitive hominin species who roamed 800,000 years earlier, to the era of Australopithecus afarensis, without considering another possible explanation, the authors and editors of Nature were somewhat foolish.

Many paleoanthropologists are in this mad rush to claim their precious find is the most human of hominins, so as to etch their name into the textbooks in rewriting human evolution, that they sometimes forget about doing thorough comparative science. And many publications are in this mad rush to publish the most human of findings, that they sometimes forget about thoroughly editing scientific works. Think that could be the case? I sure do… Why should we settle on secondary evidence for Australopithecine stone tools when none have been found yet, and when another possibility hasn’t been extensively exhausted?

McPherron, S., Alemseged, Z., Marean, C., Wynn, J., Reed, D., Geraads, D., Bobe, R., & Béarat, H. (2010). Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia Nature, 466 (7308), 857-860 DOI: 10.1038/nature09248

Afarensis shared with us a news that 35,000 year old artifacts were found from an iron ore mine site is seen at Hope Downs, Australia. I think this is a interesting find, but it is by no means the first time artifacts of this antiquity have been found in Australia, nor is it the oldest finds. The Associated Press news article by Tanalee Smith explains this distinction.

The article doesn’t tell us how these artifacts were dated, nor does it indicate if these finds will be published in a peer reviewed journal. But it does include a photo of one of the artifacts, a chert knife.

Groundstone axes below, from the Sahul landmass (actually Bobongara) have been dated to be 38,000 years old by thermoluminescence. Thermoluminescence isn’t always accurate… A 2004 review of artifacts from more than 30 archaeological sites, recently concluded Sahul was peopled around 42–45,000 years ago. This was based off of radiocarbon dating of flakes, hearths, animal bones. Lake Mungo, in south-western New South Wales, Australia, confers this time frame as well — Mungo Lady, a partially creamted body has been also dated to around 40,000 years ago.

So while this isn’t the most significant archaeological find in understanding the details of how Australia was peopled, it does shows us that people were living in more arid parts of Australia, such as the Pilbara region, earlier than previously known and had adapted and stayed.

Kenneth Collerson and Marshall Weisler the University of Queensland, Australia have been studying 19 2,000 year old adzes which were excavated in the 1930′s from coral atolls in the Tuamotus, in the Pacific. Adzes are type of stone tool that function like a pick and resemble an axe. Their research, “Stone Adze Compositions and the Extent of Ancient Polynesian Voyaging and Trade” is now published in Science.

The axe part of the adzes are made of basalt, a type of volcanic rock which was not available in the Tuamotus because the Taumotus rose up fro the sea 800 years after these basal adzes were created. The basalt probably originated from Hawaii, one of the few volcanically active islands in the Pacific, around 2,000 years ago.

“Collerson, a geochemist who studies mantle processes, knew that basalts from different types of islands have a distinctive signature in their trace elements and isotope chemistries. So the team took centimetre-wide chunks from the adzes and compared them to a database they had compiled from sites throughout the Pacific.”

What they found out is pretty remarkable. The basalt from the adzes have matching signatures to basalt from the Marquesas, Pitcairn, and the Austral islands. The research confirmed that one adze had been fashioned from hawaiite, a type of basalt specifically from the island of Kaho’olawe. Collerson says commented that hawaiite’s chemical signature matches one other one,

“the only other possible location on the planet where it could have come from is one of the islands in the middle of the Atlantic.”

This indicates that about 2,000 years ago, Polynesians were extensively travel the Pacific. Which is nothing really ground breaking. We already knew that before 2,000 years ago, Samoans and Tongans hauled out eastward. They settled many different islands and archipelagos in the Pacific Ocean, including the Cook Islands, Tahiti, and the Marquesas Islands. Within 1,000 years ago they colonized most of these places.

So the Polynesian people were moving a lot around. The linguistic data supported it, and even so recently, chicken genetics gave us a clue about what Polynesian’s were doing in South America. And now some pretty solid archaeology and geology supports it.

I’m pretty sure anthropologist Geoffrey Irwin from University of Auckland is all happy about this study.