Does not follow

Rienzi asserts, based on this study [1], that 'Personal "self-identification" is not enough. Genetic analyses of ancestry are required.' Rienzi clearly implies this study of "African Americans" indicates a need for individual genetic ancestry analysis of white Americans--an absurd conclusion.

Studies have repeatedly shown American blacks average ~20% European admixture, while white Americans show minimal if any non-European admixture. Gene flow was overwhelmingly one way.

It is no surprise that among American blacks "self-report of a high degree of African ancestry in a three-generation family tree did not accurately predict degree of African ancestry". The overwhelming majority of American blacks have "African" (black) parents and grandparents. No doubt most of Aframs' European genes entered the Afram gene pool more than 3 generation ago. Aframs without recent white ancestors may range from light-skinned to coal-black. We see no such variations in the phenotypes of white Americans.

Additionally, most white Americans who care to can construct pedigrees for themselves much deeper than three generations.

While I personally find genetic ancestry analysis interesting, and look forward to further developments in the field, as of now I see nothing of benefit for the overwhelming majority of white Americans in any commercially available test of individual admixture.


[1] Comparing genetic ancestry and self-described race in african americans born in the United States and in Africa. Yaeger R, Avila-Bront A, Abdul K, Nolan PC, Grann VR, Birchette MG, Choudhry S, Burchard EG, Beckman KB, Gorroochurn P, Ziv E, Consedine NS, Joe AK. Cancer Epidemiol Biomarkers Prev 2008;17(6):1329-38

More ancient DNA results from Xinjiang

I'm unfamiliar with the site and I haven't read the paper, but based on the dates mentioned (~500 BC to 1 AD) these results again most likely have little or no bearing on the question or the origins of the older, Northern European-looking mummies (which date to as early as ~1800 BC).

Sci China C Life Sci. 2008 Mar;51(3):205-13.

Mitochondrial DNA analysis of human remains from the Yuansha site in Xinjiang, China.

Gao S, Cui Y, Yang Y, Duan R, Abuduresule I, Mair VH, Zhu H, Zhou H.

Laboratory of Ancient DNA, Research Center for Chinese Frontier Archaeology, Jilin University, Changchun, 130012, China.

The Yuansha site is located in the center of the Taklimakan Desert of Xinjiang, in the southern Silk Road region. MtDNA was extracted from fifteen human remains excavated from the Yuansha site, dating back 2,000-2,500 years. Analysis of the phylogenetic tree and the multidimensional scaling (MDS) reveals that the Yuansha population has relatively close relationships with the modern populations of South Central Asia and Indus Valley, as well as with the ancient population of Chawuhu.

PMID: 18246308 [PubMed - indexed for MEDLINE]

Some ancient DNA results from the Tarim Basin

Note: some clown references this paper on Wikipedia in the following context:

The cemetery at Yanbulaq contained 29 mummies which date from 1800–500 BC, 21 of which are Caucasoid—the earliest Caucasoid mummies found in the Tarim Basin—and eight of which are of the same Caucasoid physical type found at Qäwrighul.[1]:237 . However, more recent genetic studies painted a more complex picture (Xie et al., 2007). It showed both european and asian characteristics.

In fact, this study has no bearing on the origins of the Northern Europoid "Tarim mummies". Sampul is a much later site, which according to physical anthropologists was populated primarily by Central Asian "Eastern Mediterranean" types. Mallory and Mair discuss the findings of Han Kangxin:

The Qäwrighul remains are relatively homogeneous and they exhibit features associated with a type known as Proto-Europoid, a rather robust Caucasoid, especially well represented in Northern Europe and the steppelands and forest-steppe of Russia and the Ukraine. Similar remains occur in the Bronze Age cemeteries of southern Siberia, Kazakhstan, Central Asia and the Lower Volga. [. . .]

The next oldest remains derive from the Yanbulaq cemetery near Humul (Hami), situated to the northeast of Qäwrighul and the easternmost cemetery investigated. Here Han Kangxin identified 21 of the 29 complete skulls as Mongoloids and these are the earliest definite evidence of Mongoloids in East Central Asia. The remaining skulls, however, belonged to Caucasoids who are closest to those from Qäwrighul and point to the same general direction for their origins, i.e. the steppelands to the north and west.

The single skull recovered from among the inhumation burials at Shambalay near Tahkurgan in the far west of the Tarim Basin has been compared with the type that spanned the Mediterranean across Central Asia; this type also includes the Saka tribes of the southern Pamirs.

A much larger sample of 58 skulls was recovered from one of the mass graves at Alwighul in the Tangri Tagh (Tian Shan). Here Han distinguishes two Caucasoids types: the Eastern Mediterranean or Indo-Afghan type with their long and high skulls and the broader and rounder skulls of the Pamir-Ferghana type; Han also identified hybrids of these two subtypes as well as some evidence of Mongoloid admixture. By now, the attentive reader will know we owe another caveat; the three physical types employed by Han Kangxin -- Proto-Europoids, Indo-Afghans and Pamir-Ferghanans -- are largely relabelled Nordics, Mediterraneans, and Alpines, terms that send shivers of apprehension down the spines of Western biological anthropologists.

[. . .]

The Sampul cemetery provides us with our only physical anthropological evidence of the southern Silk Road in the vicinity of Khotan. Although the cemetery contained various individual graves employing some form of log coffin, all the burials examined derive from the group graves which date to the first centuries BC. Han Kangxin has identified the remains as belonging to the same Indo-Afghan type that one encounters among the Saka of the southern Pamirs.

[pp. 236-239; The Tarim Mummies]

Progress in Natural Science, Volume 17, Number 8, pp. 927-933(7)

Mitochondrial DNA analysis of ancient Sampula population in Xinjiang

Xie Chengzhi Li Chunxiang Cui Yinqiu Cai Dawei Wang Haijing Zhu Hong Zhou Hui

Abstract: The archaeological site of Sampula cemetery was located about 14 km to the southwest of the Luo County in Xinjiang Khotan, China, belonging to the ancient Yutian kingdom. 14C analysis showed that this cemetery was used from 217 B.C. to 283 A.D. Ancient DNA was analyzed by 364 bp of the mitochondrial DNA hypervariable region I (mtDNA HVR-I), and by six restriction fragment length polymorphism (RFLP) sites of mtDNA coding region. We successfully extracted and sequenced intact stretches of maternally inherited mtDNA from 13 out of 16 ancient Sampula samples. The analysis of mtDNA haplogroup distribution showed that the ancient Sampula was a complex population with both European and Asian characteristics. Median joining network of U3 sub-haplogroup and multi-dimensional scaling analysis all showed that the ancient Sampula had maternal relationship with Ossetian and Iranian.

Keywords: ancient DNA mitochondrial DNA Sampula ancient populations

[link]

The authors detect the following haplogroups: U3 (in four individuals), N (x2), C (x2), B, F1a, G, M, and T2.

Oceania: tracing population history and adaptation with genome-wide SNP data

MBE Advance Access published online on June 3, 2008
Molecular Biology and Evolution, doi:10.1093/molbev/msn128

Gene Flow and Natural Selection in Oceanic Human Populations, Inferred from Genome-wide SNP Typing

Ryosuke Kimura1,*, Jun Ohashi2, Yasuhiro Matsumura3, Minato Nakazawa4, Tsukasa Inaoka5, Ryutaro Ohtsuka6, Motoki Osawa1 and Katsushi Tokunaga2

It is suggested that the major prehistoric human colonizations of Oceania occurred twice, namely, about 50,000 and 4,000 years ago. The first settlers are considered as ancestors of indigenous people in New Guinea and Australia. The second settlers are Austronesian-speaking people who dispersed by voyaging in the Pacific Ocean. In this study, we performed genome-wide SNP typing on an indigenous Melanesian (Papuan) population, Gidra, and a Polynesian population, Tongans, by using the Affymetrix 500K assay. The SNP data were analyzed together with the data of the HapMap samples provided by Affymetrix. In agreement with previous studies, our phylogenetic analysis indicated that indigenous Melanesians are genetically closer to Asians than to Africans and European Americans. Population structure analyses revealed that the Tongan population is genetically originated from Asians at 70% and indigenous Melanesians at 30%, which thus supports the so-called "Slow train" model. We also applied the SNP data to genome-wide scans for positive selection by examining haplotypic variation, and identified many candidates of locally selected genes. Providing a clue to understand human adaptation to environments, our approach based on evolutionary genetics must contribute to revealing unknown gene functions as well as functional differences between alleles. Conversely, this approach can also shed some light onto the invisible phenotypic differences between populations.

Key Words: adaptive evolution • gene flow • human genome • SNP • Oceania

http://mbe.oxfordjournals.org/cgi/content/short/msn128v1?rss=1

Isotopic analysis of an LBK mass grave

The Telegraph reports the study as follows:

Neolithic men were prepared to fight for their women

[. . .]

Many archaeologists have argued that women have long motivated cycles of violence and blood feuds throughout history but there has really been no solid archaeological evidence to support this view.

Now a relatively new method has been used to work out the origins of the victims tossed into a mass grave of skeletons, and so distinguish one tribe from another, revealing that neighbouring tribes were prepared to kill their male rivals to secure their women some 7000 years ago.

The Durham University research, described in the academic journal Antiquity, focused on 34 skeletons found buried in the village of Talheim in the south-west of Germany.

[. . .]

Lead author Dr Alex Bentley says the simplest explanation is that the women of one tribe were captured.

"It seems this community was specifically targeted, as could happen in a cycle of revenge between rival groups. Although resources and population were undoubtedly factors in central Europe around that time, women appear to be the immediate reason for the attack.

"Our analysis points to the local women being regarded as somehow special and were therefore kept alive."

Antiquity

Volume: 82 Number: 316 Page: 290–304

Isotopic signatures and hereditary traits: snapshot of a Neolithic community in Germany

R. Alexander Bentley1, Joachim Wahl2, T. Douglas Price3 and Tim C. Atkinson4

1Department of Anthropology, Durham University, 43 Old Elvet, Durham DH1 3HN, UK (Email: r.a.bentley@durham.ac.uk) 2RP Stuttgart, Landesamt für Denkmalpflege, Osteologie, Stromeyersdorfstraße 3, D-78467, Konstanz, Germany (Email: Joachim.Wahl@rps.bwl.de) 3Department. of Anthropology, University of Wisconsin, 1180 Observatory Dr., Madison, WI 53706-1393, USA (Email: tdprice@wisc.edu) 4Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK (Email: t.atkinson@ucl.ac.uk)

A group of Linearbandkeramik people at Talheim, Germany were previously found to have died at the same time, probably in a massacre, and the authors were able to ask some searching questions of their skeletons. The isotope signatures of strontium, oxygen and carbon, which gave information on diet and childhood region, showed up three groups which correlated with hereditary traits (derived previously from the analysis of the teeth). In the local group, there were many local children but no adult women, suggesting they had been selectively taken alive at the time of the massacre. Another group, with isotope signatures derived from upland areas, includes two men who may have been closely related. A third group has a composition suggestive of a nuclear family. The variations of one type of isotope signature with another suggested subtle interpretations, such as transhumance, and a probable labour division in the community between stockholders and cultivators. Here we see the ever-growing potential of these new methods for writing the ‘biographies’ of prehistoric skeletons.

Keywords: Neolithic, Germany, LBK, Talheim, isotope analysis, hereditary traits, trans-humance

http://www.antiquity.ac.uk/ant/082/ant0820290.htm

Hydraulic cement: Thank the English, not the Romans

[re: hysterical Medocentrist outburst elsewhere]

Portland cement as widely used today was originally formulated by Englishman William Aspdin, building on the work of other Englishmen, including his father Joseph Aspdin and, ultimately, John Smeaton:

Smeaton investigated the cementing properties of various mortars, made from lime obtained from various locations, and discovered that the best mortars were made from the calcination of limes that contained considerable proportions of clay minerals (argillaceous lime). This was the first occasion that the importance of clay mixed with the lime had been recognized in the formation of a hydraulic setting cement. It was found that limes that did not dissolve completely in nitric acid (clay being insoluble in the acid) possessed good hydraulic properties (Kohlhaas, 1983). The cementitious agent Smeaton finally used was made from such a clay containing lime which was mixed with an equal quantity of pozzolana (Lea, 1970). The lighthouse that he constructed stood for 123 years until 1879 and only failed when its foundations were undermined by the sea. Smeaton's conclusions about the importance of the presence of clay were not published until after his death in 1792. Smeaton was the first to call himself a civil engineer (as distinct from a military engineer). In the preface to his book, Hydraulischen Moertel, W Michaelis stated in 1869 (in translation):

A century has elapsed since the famous Smeaton completed the building of the Eddystone Lighthouse. Not only the seafaring but for all humanity stands as a true signal of blessed work, a light in the dark night. From the scientific point of view it illuminated the darkness of nearly 2000 years.

The errors which came to us from the Romans and which were shared even by the excellent Belidor, were dispersed.

The Eddystone Lighthouse is the foundation upon which our knowledge of hydraulic mortars has been built and is the chief pillar of modern construction. Smeaton freed us from the shackles of tradition by showing us that the purest and hardest limestone is not the best, at least for hydraulic purposes, and that the source of the hydraulicity of lime mortar must be sought in the argillacrious admixtures (Draffin, 1976).

The cement was called 'Roman cement' although it in no way resembled the true Roman cement, except for its hydraulic setting reactions.

[Mary S. J. Gani; Cement and Concrete; p. 5]

The Romans ceased building with high-quality concrete by around A.D. 300. Our modern knowledge of cement owes nothing to them.

Cement was used from the decline of the Empire and through the Middle Ages, but none of it was any good until comparatively recent times (Davey, 1961). [. . .]

In this case, it was not that a Roman secret was lost, rather that the Romans, who did no testing, never learned what they had. The very idea of testing is comparatively recent, and the engineer John Smeaton, who tested samples for the construction of the Eddystone Light in the years 1756– 1759 (Davey, 1961) is, I suspect, the first man on the planet deliberately to test cements of differing compositions.

[Thomas Nelson Winter. Roman Concrete: The Ascent, Summit, and Decline of an Art. Transactions of the Nebraska Academy of Sciences 7 (1979), pp. 137-143.]