Anthropology.net

It has been a while since I blogged anything on paleoanthropology. But once I saw John Hawks‘ post where he pointed out Elizabeth Culotta’s news piece in the latest Science on a new hominin femur from Galili, Ethiopia, I was excited. The femur was presented by Bence Viola to the Society of Vertebrate Paleontology, which meet for their annual get together about two weeks ago.

Galili, Ethiopia

Very recent argon-argon dating was done on, and Viola shared those to the Society. The bone is somewhere between between 4.38 million and 3.92 million years old. The bone indicates the individual was larger than lucy but isn’t complete. From what Culotta says, it seems as the distal end is broken off.

The anatomy of the head and neck of the femur suggest the owner was bipedal. But, the distribution of cortical bone around the femur is even. Arboreal primates have an even distirbution of cortical bone around the neck of the femora. The force of gravity and the weight of a bipedal individual causes a lot of stress on the lower half of the femoral neck. It has been observed that the cortical bone of femoral necks of bipedal hominids is thicker on the lower half, as a response to this stress. If you know anything about the debate between the Orrorin camp and the Ardipithecus camp, this should be all too familiar of a discussion.

I first read about hominid remains from Galili in this 2004 piece, which reported on the discovery of an almost complete lower right third molar (GLL 33) likely that of a male Australopithecus afarensis. Hawks pointed out a recent paper which describes the paleoecology of Galili — a open woodland to bushland ecosystem at a time when A. afarensis began replacing A. anamensis. So it is certainly possible that a semi-arboreal/bipedal hominids were navigating this terrain… But, Yohannes Haile-Selassie, who is also working on a 4 million years old hominid from Ethiopia, isn’t too convinced.

What do you think?

E. Culotta (2008). SOCIETY OF VERTEBRATE PALEONTOLOGY 68TH ANNUAL MEETING: Two Legs Good Science, 322 (5902), 670-671 DOI: 10.1126/science.322.5902.670b

A new paper in the open access journal PLoS Genetics reports on a comparison of genetic, geographic, and linguistic patterns of the diverse populations found on the major islands of the Bismarck Archipelago and Bougainville, Melanesia. The paper is titled, “Genetic and Linguistic Coevolution in Northern Island Melanesia.” I think that Simon Greenhill of HENRY may know a bit more about these populations, languages and region than I, but I’m gonna still try and summarize the paper and briefly discuss the results.

The earliest inhabitants of the area arrived around 40,000 years ago, but there was an additional migration into the region about 3,300 years ago. We know that primarily because of the linguistic diversity. The two major languages are Oceanic and Papuan. Oceanic, being a major branch of the widespread Austronesian language family, and the Paupuan languages, likely descendants of languages spoken by people who began arriving in the region more than 40,000 years ago. The rugged geography of the region has been a cause for a lot of the diversification. Despite their regional affinities, the two languages do not form a very coherent language family.

Genetic, Geographic & Linguistic Distances Of Melanesian Popultions

The study sampled 776 individuals from 33 linguistically based populations, which averages to about 23 individuals per population. Each individual was typed on 751 different autosomal microsatellites. The languages were compared on 108 different structural linguistic features. The authors applied two different tests to figure out if genetic and linguistic similarities were formed following early population splits and isolations or if the genetic and linguistic similarities were formed through continuing genetic and linguistic exchange between neighboring populations.

The authors were able to figure out that genes moved freely than languages between nearby populations, regardless of the language family (compare Figures B to D). Language exchanges, on the other hand, have been particularly limited between neighboring Oceanic and Papuan languages (check out Figure D & F). In certain regions, like the rugged interior of the largest island, New Britain, the authors found strong correlations between genetic, linguistic, and geographic distances when compared to their less restricted coastal neighboring populations. They are almost always distinctly different. While extremely restricted to several islands, this study shows us a scenario where language barriers do not particularly hinder genetic exchange, but geography still does.

Keith Hunley, Michael Dunn, Eva Lindström, Ger Reesink, Angela Terrill, Meghan E. Healy, George Koki, Françoise R. Friedlaender, Jonathan S. Friedlaender (2008). Genetic and Linguistic Coevolution in Northern Island Melanesia PLoS Genetics, 4 (10) DOI: 10.1371/journal.pgen.1000239