Ancient lineage of modern humans

Journal of Human Evolution (Article in Press) doi:10.1016/j.jhevol.2007.10.010

Human cranial diversity and evidence for an ancient lineage of modern humans

Michael A. Schillaci

Abstract

This study examines the genetic affinities of various modern human groupings using a multivariate analysis of morphometric data. Phylogenetic relationships among these groupings are also explored using neighbor-joining analysis of the metric data. Results indicate that the terminal Pleistocene/early Holocene fossils from Australasia exhibit a close genetic affinity with early modern humans from the Levant. Furthermore, recent human populations and Upper Paleolithic Europeans share a most recent common ancestor not shared with either the early Australasians or the early Levantine humans. This pattern of genetic and phylogenetic relationships suggests that the early modern humans from the Levant either contributed directly to the ancestry of an early lineage of Australasians, or that they share a recent common ancestor with them. The principal findings of the study, therefore, lend support to the notion of an early dispersal from Africa by a more ancient lineage of modern human prior to 50 ka, perhaps as early as OIS 5 times (76–100 ka).

Link

Y chromosome haplogroup Q5 in India

BMC Evol Biol. 2007 Nov 19;7:232.

A novel subgroup Q5 of human Y-chromosomal haplogroup Q in India.

Sharma S, Rai E, Bhat AK, Bhanwer AS, Bamezai RN.

BACKGROUND: Y-chromosomal haplogroup (Y-HG) Q is suggested to originate in Asia and represent recent founder paternal Native American radiation into the Americas. This group is delineated into Q1, Q2 and Q3 subgroups defined by biallelic markers M120, M25/M143 and M3, respectively. Recently, a novel subgroup Q4 has been identified which is defined by bi-allelic marker M346, representing HG Q (0.41%, 3/728) in Indian population. With scanty details of HG Q in Asia, especially India, it was pertinent to explore the status of the Y-HG Q in Indian population to gather an insight to determine the extent of diversity within this region. RESULTS: We observed 15/630 (2.38%) Y-HG Q individuals in India with an ancestral state at M120, M25, M3 and M346 markers, indicating an absence of already known Q1, Q2, Q3 and Q4 sub-haplogroups. Interestingly, we further observed a novel 4 bp deletion/insertion polymorphism (ss4 bp, rs41352448) at 72,314 position of human arylsulfatase D pseudogene, defining a novel sub-lineage Q5 (in 5/15 individuals, i.e., 33.3 % of the observed Y-HG Q) with distributions independent of the social, cultural, linguistic and geographical affiliations in India. CONCLUSION: The study adds another sublineage Q5 in the already existing arrangement of Y-HG Q in literature. It was quite interesting to observe an ancestral state Q* and a novel sub-branch Q5, not reported elsewhere, in Indian subcontinent, though in low frequency. A novel subgroup Q4 was identified recently which is also restricted to Indian subcontinent. The most plausible explanation for these observations could be an ancestral migration of individuals bearing ancestral lineage Q* to Indian subcontinent followed by an autochthonous differentiation to Q4 and Q5 sublineages later on. However, other explanations of, either the presence of both the sub haplogroups (Q4 and Q5) in ancestral migrants or recent migrations from central Asia, cannot be ruled out till the distribution and diversity of these subgroups is explored extensively in Central Asia and other regions.

Link

ISABS 2007 abstracts

Quite a few interesting abstracts from last year's ISABS Conference (book of abstracts).

Y-CHROMOSOME DIVERSITY IN SOUTHERN URALS: A GEOGRAPHIC BORDER BETWEEN EUROPE AND ASIA

Khusnutdinova E. et al.

Turkic-speaking Bashkirs are dispersed throughout the southern Ural region. They are considered by historians as descendants of Turkic- speaking nomadic communities that arrived in southern Urals at Early Medieval ages and assimilated indigenous population. We performed phylogenetic analysis of Y-chromosome lineages in a sample of 587 Bashkirs drawn from different parts of the southern Ural region and neighbouring areas: Abzelilovskiy (N=152), Sterlibashevskiy (N=54), Baimakskiy (N=95), and Burzyanskiy (N=82) districts of Bashkortostan republic, Orenburg (N=79), Perm (N=72), Samara and Saratov (N=51) Oblasts of Russia. Obtained samples of Y-chromosomes were analyzed using 24 biallelic markers of the Y chromosome non-recombining region. A total of 17 haplogroups were identified among which R1b3-M269, R1a1- SRY 1532, and N3-M46 lineages were predominant. Since N3-M46 lineage is prevalent among neighbouring Finno- Ugric populations and is rarely found in Central Asia, where numerous Turkicspeaking confederations dominated over a long period ancestors of Finno-Ugric groups are probable source population that contributed N3 lineage into Bashkirs. Y- Chromosome lineages specific to Central and East Asian populations (C3c- M48, O-M175) were absent or found with very low overall frequency (less than 10%). The only exception is R1b2 lineage which was found with very high frequency among Transural Bashkirs. Overall prevalence of typical West Eurasian (R1a-SRY 1532 and R1b3- M269) and North Eurasian (N3) lineages imply that Turkic-speaking newcomers were either admixed or genetic input associated with their arrival was limited.

INTRA-ETHNIC VARIATION OF THE Y CHROMOSOME IN EUROPEAN COUNTRIES: A COMPARATIVE STUDY

Balanovsky O et al.

To reveal degree of the regional Y chromosomal variation in Europe we compared our data on Russians (14 regional populations), Ukrainians (4 populations) and Belorussians (2 populations, and 2 populations from Behar et al., 2003) with the published regional data on other European countries. For reliable calculations neighbour populations were pooled to reach sample sizes above 70. To measure the intra-ethnic variation we calculated (i) the average genetic distance between regional populations of every group and (ii) Gst (Fst) variation. Gst value was considered as preferable measure, as it was found to be less sensitive to level of phylogenetic resolution in the data. Croatians, Finns, Russians and Italians were proved to be the most diverse (genetically subdivided) groups; Swedes and Germans demonstrated moderate variation; Greeks, Turks, Poles, Belorussians and Ukrainians were more genetically homogenous, showing lower geographic variation of the paternal lineages inside their countries. However, even lower variation of the Y chromosome is significantly higher as compared with analogous values calculated from mitochondrial DNA and autosomal data. This finding stresses that forensic studies may demand not only country-specific, but provincespecific databases (at least for listed above highly genetically subdivided countries), since haplogroup profiles differ significantly from one province to another, inside the same country. Despite the high intra-ethnic variation (Gst=0.03 on average), the inter-ethnic differences were five times higher (Gst=0.15), revealing dominance of inter-ethnic variation in structuring the paternal gene pool in Europe.

PHYLOGEOGRAPHY OF Y-CHROMOSOMAL LINEAGES IN NORTH EURASIA

Stepanov V et al.

Aim of the study was to reconstruct the evolution of paternal lineages in populations of Siberia, Central Asia and Eastern Europe. Forty population samples from 22 ethnic groups were studied. Totally 1600 Y chromosomes were genotyped for 40 biallelic markers according to Y chromosome consortium (YCC) classification. The microsatellite haplotypes within HG were constructed using 7 STR loci. Thirty one haplogroups were observed, but frequencies of only 7 of them (N3a, R1a1, Q*, C3xC3c, N2, C3c, O3) were higher than 3 percent. In sum these 7 haplogroups comprise 86% of Y-chromosomal gene pool in North Eurasia. The proportion of inter- population differences in the total genetic variability of region's population according to the analysis of molecular variance is 19%. Analysis of genetic relationships between populations reveals three main clusters of populations in space of two first PCs reflecting the differential presence of ancient West-Eurasian Caucasoid, Proto-Uralic and Paleoasiatic components. Based on analysis of microsatellite haplotypes within main Y- chromosomal haplogroups, molecular diversity within monophyletic lineages were calculated and phylogenetic trees for most common haplogroups were reconstructed. Western-Eurasian lineages (R1a1, R1b) are characterized by the maximal diversity in Eastern European populations. Eastern-Eurasian lineages have the high level of diversity in populations of Eastern Siberia and North-East Asia. The age of genetic diversity generation and time of population differentiation (Td) shows that most lineages which are common in North Eurasian populations dated back to Upper Paleolithic period before the last glacial maximum.

THE MITOCHONDRIAL DNA POLYMORPHISM IN UKRAINIAN POPULATION

Grechanina EY et al.

Study of mtDNA polymorphism for estimation genetic diversity of Ukrainian population. There are 239 samples of Ukrainians from different regions of Ukraine. There are sequention of hypervariable segment HVS I in combination with RFLPanalysis of coding sites of mtDNA and phylogeographical analysis. This research was in Estonian Biocenter. Length of sequencing fragment was 377 bp 102 positions from 377 were polymorphic. From these 91 nucleotide substitutions are transitions, with prevalence pyrimidine under purine (69:22). Transversions were in 11 sites. Were determined 157 haplotypes. The most common haplotype (10.0%) corresponds to CRS. Indexes of genetic diversity for Ukrainian population are H=0.986 and Di=5.19. Screening of polymorphic sites established following haplogroups of mtDNA, which have all-European spreading: H-33.5%, V-5.4%, HV-3.7%, J- 11.7%, T-6.7%, U-20.9% (U2, U3, U4, U5, U7, U8), K-2.9%, I-2.1%, W- 2.1%, X-2.5%. Subhaplogroup U3 (2.5%) may testify the presence Iranian component. Subhaplogroup U4 was detected with frequency 3.7%. Subhaplogroup U5 has maximal frequency in Scandinavian people also was detected in Ukrainian population with high frequency 10.8%. Haplogroup V, as marker of Finnish-Hungarian people, has high frequency in Ukrainian population. There were found Asian lines (A, B, C, D, Z) with frequency 2.0%. Data indicate on complicated ethnical formation of modern Ukrainian population, where assimilation processes and inter-ethnic interactions played considerable role. They will be important additions in context about polymorphism of European populations mtDNA.

A GLIMPSE AT THE FRENCH mtDNA GENETIC POOL

Pennarun E et al.

In the coverage of the genetic pool of Europe, some major cavities were left, hence to fill one of them, namely the French mtDNA pool we collected 868 samples from twelve different locations of France. Those samples were sequenced for the hypervariable segment I (HVS-I) and then typed for SNPs in the coding region, either by RFLP or 5' nuclease allelic discrimination, in order to assign them to the right haplogroup. Then the mtDNA gene pools of French Basques and Bretons were compared in terms of frequency and composition with relevant neighbouring populations. The French Basques’ mtDNA pool shares some common cardinal features with that of the Spanish Basques, represented in the high prevalence of haplogroup H. However, the French Basques do show a number of distinct features, most notably expressed in the much higher frequency of haplogroups linked with the Neolithic diffusion in Europe. In Brittany, Finistère shows closer affinities with Britain and Scandinavia than the two other departments of Brittany. The mtDNA haplogroup composition of the French does not differ significantly from the surrounding European genetic landscape. In a finer grain, microgeographical differentiation can be revealed as shown for the French Basque country and for Brittany.

CULTURAL AND GENETIC DIVERSITY IN CENTRAL ANATOLIA: A LOCAL PERSPECTIVE

Gokcumen O et al.

Anatolia has been an important crossroads for numerous populations since the Neolithic. Among these, the Hattis, Urartians, Lydians, Phyrigians and Ottomans emerged in Anatolia proper. In addition, although non-Anatolian in origin, the Hittites, Greeks, Romans and Byzantines influenced and were influenced by local Anatolian cultures. These dynamics, as well as more recent events, such as the Turco-Ottoman War of late 19th century, the reconfiguration of the populations of the Ottoman Empire and the Greek- Turkish population exchange of 1920s, have made Anatolia a culturally and genetically complex region. Despite this complex history, Anatolia has been often been viewed as a uniform cultural landscape. Working from this perspective, previous studies of genetic variation in Anatolia analyzed samples from Turkish populations obtained from mostly urban hospitals or universities. Such studies not only overlooked the regional variation within Anatolia, but also treated contemporary Turkish populations as the direct representatives of Medieval and Neolithic Anatolian populations. To address these problems, we collected ~125 samples and extensive ethnographic data from a location in Central Anatolia southeast of Ankara. The samples were analyzed for mtDNA and NRY diversity, and the resulting data compared with those from previous genetic analyses of Turkish populations. We observed that several ethnic and cultural groups having different population histories co-existed in this location. This pattern likely represents the typical picture of Anatolian variation. We are using our genetic data to help us clarify these distinct population histories in greater detail.

Genetic traces of east-to-west human expansion waves in Eurasia

American Journal of Physical Anthropology (early view)

Genetic traces of east-to-west human expansion waves in Eurasia

Raphaëlle Chaix et al.

In this study, we describe the landscape of human demographic expansions in Eurasia using a large continental Y chromosome and mitochondrial DNA dataset. Variation at these two uniparentally-inherited genetic systems retraces expansions that occurred in the past 60 ky, and shows a clear decrease of expansion ages from east to west Eurasia. To investigate the demographic events at the origin of this westward decrease of expansion ages, the estimated divergence ages between Eurasian populations are compared with the estimated expansion ages within each population. Both markers suggest that the demographic expansion diffused from east to west in Eurasia in a demic way, i.e., through migrations of individuals (and not just through diffusion of new technologies), highlighting the prominent role of eastern regions within Eurasia during Palaeolithic times.

Link

mtDNA of Altaian Kazakhs from Russia

From the paper:

In this study, we also find that all Turkic and Mongolic groups possess a common set of maternal haplogroups (C, D, G2a, H), and a minimal number of haplotypes from these lineages at appreciable frequencies. However, the overall patterns of haplotype sharing amongst these groups vary considerably. This finding is not necessarily incompatible with the cultural diffusion model per se, but implies that present day Turkic-Mongolic ethnic groups emerged from a common mtDNA pool that was widely distributed in Central and East Asia.

This suggests that the movements of Turkic-Mongolic people did not consist only of males but also had a female component to them. Also of interest from the paper:

Haplogroup N1a was also present in the Altaian Kazakhs. Seeing as how there were no occurrences of this lineage in other Kazakh populations or neighboring populations (Kolman et al., 1996; Comas et al., 1998; Yao et al., 2004), this finding was intriguing (Table 3). The haplotypic variation within the seven N1a samples was relatively high (Table 2), with these haplotypes belonging to both the European and Central Asian branches of this haplogroup, as recently defined by Haak et al. (2005). Thus, the source of N1a haplotypes in Altaian Kazakhs was unclear, although they seemed to have originated west of this part of Central Asia (Gokcumen et al., 2007).

Interestingly, mtDNA haplogroup N1a also pops up in Havik Brahmins from India, ancient high status Hungarians, as well as Iron Age Kazakhstan, and Neolithic Central Europeans.

American Journal of Physical Anthropology (early view)

Genetic variation in the enigmatic Altaian Kazakhs of South-Central Russia: Insights into Turkic population history

Omer Gokcumen et al.

The Altaian Kazakhs, a Turkic speaking group, now reside in the southern part of the Altai Republic in south-central Russia. According to historical accounts, they are one of several ethnic and geographical subdivisions of the Kazakh nomadic group that migrated from China and Western Mongolia into the Altai region during the 19th Century. However, their population history of the Altaian Kazakhs and the genetic relationships with other Kazakh groups and neighboring Turkic-speaking populations is not well understood. To begin elucidating their genetic history, we analyzed the mtDNAs from 237 Altaian Kazakhs through a combination of SNP analysis and HVS1 sequencing. This analysis revealed that their mtDNA gene pool was comprised of roughly equal proportions of East (A-G, M7, M13, Y and Z) and West (H, HV, pre-HV, R, IK, JT, X, U) Eurasian haplogroups, with the haplotypic diversity within haplogroups C, D, H, and U being particularly high. This pattern of diversity likely reflects the complex interactions of the Kazakhs with other Turkic groups, Mongolians, and indigenous Altaians. Overall, these data have important implications for Kazakh population history, the genetic prehistory of the Altai-Sayan region, and the phylogeography of major mitochondrial lineages in Eurasia.

Link

Grandmothers' longevity negatively affects daughters' fertility

American Journal of Physical Anthropology (early view)

Grandmothers' longevity negatively affects daughters' fertility

Lorena Madrigal, Mauricio Meléndez-Obando

Abstract

The evolution of postmenopausal longevity in human females has been the subject of debate. Specifically, there is disagreement about whether the evolution of the trait should be understood as an adaptive or a neutral process, and if the former, what the selective mechanism is. There are two main adaptive proposals to explain the evolution of postreproductive longevity: the grandmother and the mother hypotheses. The grandmother hypothesis proposes that postreproductive longevity evolved because it is selectively advantageous for females to stop reproducing and to help raise their grandchildren. The mother hypothesis states that postmenopausal longevity evolved because it is advantageous for women to cease reproduction and concentrate their resources and energy in raising the children already produced. In this article, we test the mother and the grandmother hypotheses with a historical data set from which we bootstrapped random samples of women from different families who lived from the 1500s to the 1900s in the central valley of Costa Rica. We also compute the heritability of longevity, which allows us to determine if genes involved in longevity are nearly fixed in this population. Here we show that although longevity positively affects a woman's fertility, it negatively affects her daughter's fertility; for this reason, the heritability of longevity is unexpectedly high. Our data provide strong grounds for questioning the universality of the grandmother hypothesis and for supporting the mother hypothesis as a likely explanation for the evolution of human postreproductive longevity.

Link

Using pedigree information to infer ancestral proportions

This is a nice paper, which would be potentially very useful to genetic genealogists. Roughly speaking, existing methods for inferring ancestry rely either on pedigrees (one's ancestry is inferred from the ancestry of one's known ancestors), or on comparisons between the genotype of the unknown individual and those of reference populations. The novelty is this work is that it shows how genotypes and pedigree data can be combined to provide a better estimate of a person's ancestral proportions.

Am J Hum Genet. 2008 Mar;82(3):748-55.

Estimating ethnic admixture from pedigree data.

Sinsheimer JS, Plaisier CL, Huertas-Vazquez A, Aguilar-Salinas C, Tusie-Luna T, Pajukanta P, Lange K.

This paper introduces a likelihood method of estimating ethnic admixture that uses individuals, pedigrees, or a combination of individuals and pedigrees. For each founder of a pedigree, admixture proportions are calculated by conditioning on the pedigree-wide genotypes at all ancestry-informative markers. These estimates are then propagated down the pedigree to the nonfounders by a simple averaging process. The large-sample standard errors of the founders' proportions can be similarly transformed into standard errors for the admixture proportions of the descendants. These standard errors are smaller than the corresponding standard errors when each individual is treated independently. Both hard and soft information on a founder's ancestry can be accommodated in this scheme, which has been implemented in the genetic software package Mendel. The utility of the method is demonstrated on simulated data and a real data example involving Mexican families of mixed Amerindian and Spanish ancestry.

Link

Discovery of Mycenaean tomb in Lefkada

Ancient Tomb Discovered on Greek Island

ATHENS, Greece (March 5) - Road construction on the western Greek island of Lefkada has uncovered and partially destroyed an important tomb with artifacts dating back more than 3,000 years, officials said on Wednesday.

The find is a miniature version of the large, opulent tombs built by the rulers of Greece during the Mycenaean era, which ended around 1100 B.C. Although dozens have been found in the mainland and on Crete, the underground, beehive-shaped monuments are very rare in the western Ionian Sea islands, and previously unknown on Lefkada.

...

She said the tomb contained several human skeletons, as well as smashed pottery, two seal stones, beads made of semiprecious stones, copper implements and clay loom weights. It appeared to have been plundered during antiquity.

With a nine-foot diameter, the tomb is very small compared to others, such as the Tomb of Atreus in Mycenae, which was more than 46 feet across and built of stones weighing up to 120 tons.

Adaptations to Climate in Candidate Genes for Common Metabolic Disorders

This is an open access article, so you can read it all for yourselves; the main conclusion is easy enough to grasp:

• Genes related to metabolic disorders influence the body's energy management
• Energy management is crucial for adapting to different climates, e.g., managing cold (example the higher basal metabolic rate of the Siberian Yakut).
  
• It is expected theoretically that such genes would have been subjected to natural selection as humans spread around the world and found themselves in different climates
  

Indeed, this theoretical prediction is supported by the data. What this means, practically, is that for many genes involved in metabolism, similarity of climate implies to some extent similar allele distributions, due to similar selective pressures; spatial proximity or population history do not suffice. Indeed, Natural selection has driven population differentiation in modern humans.

It is noteworthy how much research into the evolution of humans has been based on the 52 populations of the Human Genome Diversity Project. It is precisely by looking at how human populations differ from each other genetically, and correlating this with their different environments and cultures that we will be able to derive a more complete history of our species.

(Yann also blogged about this)

PLoS Genetics

Adaptations to Climate in Candidate Genes for Common Metabolic Disorders

Angela M. Hancock et al.

Evolutionary pressures due to variation in climate play an important role in shaping phenotypic variation among and within species and have been shown to influence variation in phenotypes such as body shape and size among humans. Genes involved in energy metabolism are likely to be central to heat and cold tolerance. To test the hypothesis that climate shaped variation in metabolism genes in humans, we used a bioinformatics approach based on network theory to select 82 candidate genes for common metabolic disorders. We genotyped 873 tag SNPs in these genes in 54 worldwide populations (including the 52 in the Human Genome Diversity Project panel) and found correlations with climate variables using rank correlation analysis and a newly developed method termed Bayesian geographic analysis. In addition, we genotyped 210 carefully matched control SNPs to provide an empirical null distribution for spatial patterns of allele frequency due to population history alone. For nearly all climate variables, we found an excess of genic SNPs in the tail of the distributions of the test statistics compared to the control SNPs, implying that metabolic genes as a group show signals of spatially varying selection. Among our strongest signals were several SNPs (e.g., LEPR R109K, FABP2 A54T) that had previously been associated with phenotypes directly related to cold tolerance. Since variation in climate may be correlated with other aspects of environmental variation, it is possible that some of the signals that we detected reflect selective pressures other than climate. Nevertheless, our results are consistent with the idea that climate has been an important selective pressure acting on candidate genes for common metabolic disorders.

Link

Early Bronze Age cemetary in Pella

Kathimerini has a news story about the discovery of an ancient cemetary dating from the early Bronze Age in Pella, the historical Macedonian capital. Excerpt:

Exciting new finds at the archaeological site of Pella have opened a new chapter in Macedonian history. Beneath the ruins of the ancient capital of the Macedonian kingdom is a large prehistoric burial ground that has yielded the first evidence of organized life in Pella during the third millennium BC.

It was while they were engaged in conservation, repairs and other work to highlight the site that the excavation team from Aristotle University came across more than 100 Early Bronze Age burials in large jars, accompanied by marble works of art from the Cyclades, local ceramics and metalware.

The finds are so recent that experts at the Demokritos Center have not yet completed the analysis of bones that will yield precise dates. However, the initial evidence supplements what is already known about Pella in the Early Bronze Age (2100-2000 BC), when it was the most important city in Bottiaea, long before it was made capital of the Macedonian realm. What became known as “the greatest of Macedonian cities” was apparently built on top of the prehistoric graveyard when Archelaus moved his capital there from Aiges, excavation director Professor Ioannis Akamatis told Kathimerini.

Single origin of Native Americans based on full mtDNA sequencing

You might also want to read East-West cranial differentiation in Central and Northern America and New synthesis on the first arrivals into the New World. The latter study gives a 15kya age for the expansion into the Americas which is comparable to the 18-15kya figure given by the current mtDNA-based study.

Am J Hum Genet. 2008 Feb 27 [Epub ahead of print]

Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a Coastal Route for the Peopling of the Americas.

Fagundes NJ, Kanitz R, Eckert R, Valls AC, Bogo MR, Salzano FM, Smith DG, Silva WA Jr, Zago MA, Ribeiro-Dos-Santos AK, Santos SE, Petzl-Erler ML, Bonatto SL.

It is well accepted that the Americas were the last continents reached by modern humans, most likely through Beringia. However, the precise time and mode of the colonization of the New World remain hotly disputed issues. Native American populations exhibit almost exclusively five mitochondrial DNA (mtDNA) haplogroups (A-D and X). Haplogroups A-D are also frequent in Asia, suggesting a northeastern Asian origin of these lineages. However, the differential pattern of distribution and frequency of haplogroup X led some to suggest that it may represent an independent migration to the Americas. Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple-migration models. A detailed demographic history of the mtDNA sequences estimated with a Bayesian coalescent method indicates a complex model for the peopling of the Americas, in which the initial differentiation from Asian populations ended with a moderate bottleneck in Beringia during the last glacial maximum (LGM), around approximately 23,000 to approximately 19,000 years ago. Toward the end of the LGM, a strong population expansion started approximately 18,000 and finished approximately 15,000 years ago. These results support a pre-Clovis occupation of the New World, suggesting a rapid settlement of the continent along a Pacific coastal route.

Link

AAPA 2008 abstracts

The 2008 meeting of the American Association of Physical Anthropologists will take place this April, and the book of abstracts for the conference is online in pdf format. As usual, there is a great variety of exciting research to be announced in the meeting; here is my sampling thereof:

A seemingly very important new piece of work on Central Anatolia:

O. Gokcumen et al., The Land of the Tired Ox: Ethnogenetic Insights into Rural Central Anatolian Population History

Excerpt: "For example, in one study area in the vicinity of Ankara, we have observed at least four distinct groups based on historical and ethnographic observations. Their self-claimed ancestries trace back to Afsar, Kurdish, Caucasian Cherkess, and Karaman groups. These groups came into the same area from different source regions and at different moments in history. Indeed, our data indicate that there were significant disparities between the paternal and maternal genetic diversity among these groups. These data also allow us to more accurately reconstruct the population history of the study area, as well as begin to provide new perspectives on the regional history of Central Anatolia in relation to historical Turkic invasions and perhaps the Neolithic transition. Finally, we discuss the utility of a more focal and detailed sampling approach for elucidating Anatolian population history."

I can only hope that more researchers will look into historical processes that have shaped modern populations. Too often I see research published which tries to infer human prehistory from modern populations, seemingly oblivious to the complex set of events in historical time that have shaped these populations. Anatolia, so often discussed in the context of the origin of the Neolithic is a prime example of this, as it contains multiple layers of population settlement and ethnic change.

M. C. Dulik et al. Y-chromosome variation in Altaian ethnic groups

Excerpt: "A large portion of all Altaian haplotypes belonged to haplogroup R. Differences in haplogroup frequency between the northern and southern Altaian populations were also observed, with more individuals from northern groups belonging to haplogroups N and Q, and haplogroup C being more prevalent in southern populations. In addition, there were village level patterns of NRY variation, while the overall diversity of NRY haplotypes suggested a significant cultural influence on the partitioning of genetic variation (i.e., patrilocality)."

The three elements involved in Siberian prehistory are indeed haplogroup R, in particular R1a1 which (in my opinion) represents the Western-derived Caucasoid element of likely Iranic affiliation, haplogroups N and Q which represent the Palaeo-Mongoloid element indigenous to Siberia and which has radiated from Siberia to the west (in the case of N) and to the east and into the Americas (in the case of Q), and the Mongoloid proper element which is associated with haplogroup C in this region, and which reflects the Eastern-derived movements of Mongoloid(-influenced) Altaic speakers such as the Mongols.

L. Pipes et al. Analysis of mtDNA in Mongolian Populations

J. Hawks. "Adaptive evolution of human hearing and the appearance of language"

Language requires not only a detailed anatomical and neurological system of language production, but also a highly adapted system of reception. Considering the frequency and amplitude range of human speech, the necessity of perceiving a large number of distinct speakers, the extended life history of humans, the need for children to learn phonemic distinctions at an early age, and the spatial distances covered by vocal communication in humans compared to other primates, it is likely that humans have distinctive auditory adaptations to language. This study tests the hypothesis of selection on the human auditory system, by interspecific genomic comparisons and genome-wide selection scans in living people. A set of hearing-related human genes shows clear signs of recurrent selected substitutions in humans compared to chimpanzees and macaques. These recurrent substitutions may have occurred at any time during human evolutionary history, but they were repeated with several selected variants for each gene. A smaller set of genes shows signs of significant population differentiation within the past 50,000 years, due to recent strong selection. Further, a relatively large set of hearing-related genes have segregating variants under recent strong selection in one or more human populations. These genes reflect continuing selection on hearing within the last 2000—3000 years. Together, these results suggest that human vocal communication exerted repeated selection pressures on the auditory system, that the system of human language continued to evolve during the Late Pleistocene, and that humans may still be adapting to language.

It seems that Hawks et al. paper on accelerated recent human evolution was just the beginning...

B.E. Hemphill. Are the inhabitants of Madaklasht an emigrant Persian population in northern Pakistan?: a dental morphometric investigation.

The answer: "Madaklasters share closest affinities to prehistoric Central Asians and more distant affinities to prehistoric inhabitants of the Iranian Plateau. Such results support the claim that the inhabitants of Madaklast are an intrusive population into Pakistan whose origins most likely may be found in northeastern Afghanistan and Tajikistan."

Someone should look at their genes. Human history is a giant jigsaw puzzle and it is populations that differ from their neighbors and came from somewhere else that allow us to catch a glimpse of the past (in this case prehistoric Central Asia).

N. Seguchi. "Re-analysis of the ainu-samurai hypothesis using population genetic analysis."

The conclusion: "The result shows that the Kamakura ties to the Ainu first, before it ties to the other ethnic Japanese. In addition, the Kamakura group shows more variability,indicating that the Kamakura group may have experienced significantly more gene flow. This indicates the Ainu-derived people who lived in East Japan at that time made a genetic contribution to the warrior class of Kamakura."

J. K. Rilling et al. "Abdominal depth as a principal determinant of human female attractiveness."

Excerpt: "Multiple linear regression analysis revealed that the depth of the lower torso at the umbilicus, or abdominal depth, was the strongest predictor of attractiveness, stronger than either BMI or WHR, and that its impact was significantly greater for video and side view stimuli in which it was clearly visible compared with front and back view stimuli. Women with shallow abdominal depth are more likely to be healthy, fertile and non-pregnant, suggesting that this may be an adaptive male preference that has been shaped by natural selection."

The face of Johann Sebastian Bach

A reader alerts me to a new forensic reconstruction of J. S. Bach. You can read about it (in English) in Deutsche Welle:

He only posed for one portrait, by Leipzig painter Elias Gottlob Haussmann, which has been reproduced in countless books.

But can anyone be sure that's really what Bach looked like?

Working with a cast of the composer's skull on loan from the Bach Museum in Eisenach, Scottish anthropologist Caroline Wilkinson has created a 3-D representation of the face of a man who died in 1750 at the age of 65.

Northern dogs, ancient and modern

This is an interesting study because it highlights once again a very important point: conclusions about prehistoric events based on modern populations should always be taken with a grain of salt. In this case, modern Scandinavian dogs harbor an mtDNA haplogroup at high frequency (HgD) not found in other dog breeds. This led previous research into the erroneous conclusion that there was an ancient dog domestication event in prehistoric Scandinavia. However, when one looks at actual ancient Scandinavian dogs, one fails to find HgD. Thus the suggestion that modern northern European dogs are similar to ancient northern European dogs is not supported.

BMC Evol Biol. 2008 Feb 28;8(1):71 [Epub ahead of print]

Barking up the wrong tree: Modern northern European dogs fail to explain their origin.

Malmstrom H, Vila C, Gilbert MT, Stora J, Willerslev E, Holmlund G, Gotherstrom A.

ABSTRACT: BACKGROUND: Geographic distribution of the genetic diversity in domestic animals, particularly mitochondrial DNA, has often been used to infer centers of domestication. The underlying presumption is that phylogeographic patterns among domesticates were established during, or shortly after the domestication. Human activities are assumed not to have altered the haplogroup frequencies to any great extent. We studied this hypothesis by analyzing 24 mtDNA sequences in ancient Scandinavian dogs. Breeds originating in northern Europe are characterized by having a high frequency of mtDNA sequences belonging to a haplogroup rare in other populations (HgD). This has been suggested to indicate a possible origin of the haplogroup (perhaps even a separate domestication) in central or northern Europe. RESULTS: The sequences observed in the ancient samples do not include the haplogroup indicative for northern European breeds (HgD). Instead, several of them correspond to haplogroups that are uncommon in the region today and that are supposed to have an Asian origin. CONCLUSION: Thus, we find no evidence for local domestication. We conclude that interpretation of the processes responsible for current domestic haplogroup frequencies should be carried out with caution if based only on contemporary data. They do not only tell their own story, but also that of humans.

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mtDNA of Karkar Islanders

Info on Karkar Island in Wikipedia.

Ann Hum Genet. 2008 Feb 28 [Epub ahead of print]

Mitochondrial DNA Variation in Karkar Islanders.

Ricaut FX, Thomas T, Arganini C, Staughton J, Leavesley M, Bellatti M, Foley R, Mirazon Lahr M.

We analyzed 375 base pairs (bp) of the first hypervariable region (HVS-I) of the mitochondrial DNA (mtDNA) control region and intergenic COII/tRNA(Lys) 9-bp deletion from 47 Karkar Islanders (north coast of Papua New Guinea) belonging to the Waskia Papuan language group. To address questions concerning the origin and evolution of this population we compared the Karkar mtDNA haplotypes and haplogroups to those of neighbouring East Asians and Oceanic populations. The results of the phylogeographic analysis show grouping in three different clusters of the Karkar Islander mtDNA lineages: one group of lineages derives from the first Pleistocene settlers of New Guinea-Island Melanesia, a second set derives from more recent arrivals of Austronesian speaking populations, and the third contains lineages specific to the Karkar Islanders, but still rooted to Austronesian and New Guinea-Island Melanesia populations. Our results suggest (i) the absence of a strong association between language and mtDNA variation and, (ii) reveal that the mtDNA haplogroups F1a1, M7b1 and E1a, which probably originated in Island Southeast Asia and may be considered signatures of Austronesian population movements, are preserved in the Karkar Islanders but absent in other New Guinea-Island Melanesian populations. These findings indicate that the Karkar Papuan speakers retained a certain degree of their own genetic uniqueness and a high genetic diversity. We present a hypothesis based on archaeological, linguistic and environmental datasets to argue for a succession of (partial) depopulation and repopulation and expansion events, under conditions of structured interaction, which may explain the variability expressed in the Karkar mtDNA.

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Who's a Jew?

Steve Sailer points me to this article in the New York Times regarding the strict criteria adopted by the Chief Rabbinate in Israel:

One day last fall, a young Israeli woman named Sharon went with her fiancé to the Tel Aviv Rabbinate to register to marry. They are not religious, but there is no civil marriage in Israel. The rabbinate, a government bureaucracy, has a monopoly on tying the knot between Jews. The last thing Sharon expected to be told that morning was that she would have to prove — before a rabbinic court, no less — that she was Jewish. It made as much sense as someone doubting she was Sharon, telling her that the name written in her blue government-issue ID card was irrelevant, asking her to prove that she was she.

...

In recent years, the state’s Chief Rabbinate and its branches in each Israeli city have adopted an institutional attitude of skepticism toward the Jewish identity of those who enter its doors. And the type of proof that the rabbinate prefers is peculiarly unsuited to Jewish life in the United States. The Israeli government seeks the political and financial support of American Jewry. It welcomes American Jewish immigrants. Yet the rabbinate, one arm of the state, increasingly treats American Jews as doubtful cases: not Jewish until proved so.

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Seth Farber is an American-born Orthodox rabbi whose organization — Itim, the Jewish Life Information Center — helps Israelis navigate the rabbinic bureaucracy. He explained to me recently that the rabbinate’s standards of proof are now stricter than ever, and stricter than most American Jews realize. Referring to the Jewish federations, the central communal and philanthropic organizations of American Jewry, he said, “Eighty percent of federation leaders probably wouldn’t be able to reach the bar.” To assist people like Sharon, Farber has become a genealogical sleuth. He is the first to warn, though, that solving individual cases cannot solve a deeper crisis.

If you want to find out the end of Sharon's story, read the article. This story highlights the deep divide between those with a more subjectivistic idea of religious identity or ethnicity, emphasizing self-image, and those seeking a set of more objective criteria.