37,000 year old skull from Malaysia related to indigenous people of Borneo

Front. Ecol. Evol., 27 June 2016 | http://dx.doi.org/10.3389/fevo.2016.00075

Deep Skull from Niah Cave and the Pleistocene Peopling of Southeast Asia

Darren Curnoe et al.

The Deep Skull from Niah Cave in Sarawak (Malaysia) is the oldest anatomically modern human recovered from island Southeast Asia. For more than 50 years its relevance to tracing the prehistory of the region has been controversial. The most widely held view, originating with Brothwell's 1960 description and analysis, is that the Niah individual is related to Indigenous Australians. Here we undertake a new assessment of the Deep Skull and consider its bearing on this question. In doing so, we provide a new and comprehensive description of the cranium including a reassessment of its ontogenetic age, sex, morphology, and affinities. We conclude that this individual was most likely to have been of advanced age and female, rather than an adolescent male as originally proposed. The morphological evidence strongly suggests that the Deep Skull samples the earliest modern humans to have settled Borneo, most likely originating on mainland East Asia. We also show that the affinities of the specimen are most likely to be with the contemporary indigenous people of Borneo, although, similarities to the population sometimes referred to as Philippine Negritos cannot be excluded. Finally, our research suggests that the widely supported “two-layer” hypothesis for the Pleistocene peopling of East/Southeast Asia is unlikely to apply to the earliest inhabitants of Borneo, in-line with the picture emerging from genetic studies of the contemporary people from the region.

Link

700 thousand year old ancestors of H. floresiensis

Nature 534, 245–248 (09 June 2016) doi:10.1038/nature17999

Homo floresiensis-like fossils from the early Middle Pleistocene of Flores

Gerrit D. van den Bergh, Yousuke Kaifu, Iwan Kurniawan, Reiko T. Kono, Adam Brumm, Erick Setiyabudi, Fachroel Aziz & Michael J. Morwood

The evolutionary origin of Homo floresiensis, a diminutive hominin species previously known only by skeletal remains from Liang Bua in western Flores, Indonesia, has been intensively debated. It is a matter of controversy whether this primitive form, dated to the Late Pleistocene, evolved from early Asian Homo erectus and represents a unique and striking case of evolutionary reversal in hominin body and brain size within an insular environment1, 2, 3, 4. The alternative hypothesis is that H. floresiensis derived from an older, smaller-brained member of our genus, such as Homo habilis, or perhaps even late Australopithecus, signalling a hitherto undocumented dispersal of hominins from Africa into eastern Asia by two million years ago (2 Ma)5, 6. Here we describe hominin fossils excavated in 2014 from an early Middle Pleistocene site (Mata Menge) in the So’a Basin of central Flores. These specimens comprise a mandible fragment and six isolated teeth belonging to at least three small-jawed and small-toothed individuals. Dating to ~0.7 Ma, these fossils now constitute the oldest hominin remains from Flores7. The Mata Menge mandible and teeth are similar in dimensions and morphological characteristics to those of H. floresiensis from Liang Bua. The exception is the mandibular first molar, which retains a more primitive condition. Notably, the Mata Menge mandible and molar are even smaller in size than those of the two existing H. floresiensis individuals from Liang Bua. The Mata Menge fossils are derived compared with Australopithecus and H. habilis, and so tend to support the view that H. floresiensis is a dwarfed descendent of early Asian H. erectus. Our findings suggest that hominins on Flores had acquired extremely small body size and other morphological traits specific to H. floresiensis at an unexpectedly early time.

Link

Nature 534, 249–253 (09 June 2016) doi:10.1038/nature17663

Age and context of the oldest known hominin fossils from Flores

Adam Brumm, Gerrit D. van den Bergh, Michael Storey, Iwan Kurniawan, Brent V. Alloway, Ruly Setiawan, Erick Setiyabudi, Rainer Grün, Mark W. Moore, Dida Yurnaldi, Mika R. Puspaningrum, Unggul P. Wibowo, Halmi Insani, Indra Sutisna, John A. Westgate, Nick J. G. Pearce, Mathieu Duval, Hanneke J. M. Meijer, Fachroel Aziz, Thomas Sutikna, Sander van der Kaars, Stephanie Flude & Michael J. Morwood

Recent excavations at the early Middle Pleistocene site of Mata Menge in the So’a Basin of central Flores, Indonesia, have yielded hominin fossils1 attributed to a population ancestral to Late Pleistocene Homo floresiensis2. Here we describe the age and context of the Mata Menge hominin specimens and associated archaeological findings. The fluvial sandstone layer from which the in situ fossils were excavated in 2014 was deposited in a small valley stream around 700 thousand years ago, as indicated by 40Ar/39Ar and fission track dates on stratigraphically bracketing volcanic ash and pyroclastic density current deposits, in combination with coupled uranium-series and electron spin resonance dating of fossil teeth. Palaeoenvironmental data indicate a relatively dry climate in the So’a Basin during the early Middle Pleistocene, while various lines of evidence suggest the hominins inhabited a savannah-like open grassland habitat with a wetland component. The hominin fossils occur alongside the remains of an insular fauna and a simple stone technology that is markedly similar to that associated with Late Pleistocene H. floresiensis.

Link

Middle (not Upper) Paleolithic hobbits

Nature (2016) doi:10.1038/nature17179

Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia

Thomas Sutikna, Matthew W. Tocheri, Michael J. Morwood, E. Wahyu Saptomo, Jatmiko, Rokus Due Awe, Sri Wasisto, Kira E. Westaway, Maxime Aubert, Bo Li, Jian-xin Zhao, Michael Storey, Brent V. Alloway, Mike W. Morley, Hanneke J. M. Meijer, Gerrit D. van den Bergh, Rainer Grün, Anthony Dosseto, Adam Brumm, William L. Jungers & Richard G. Roberts

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia)1, 2, 3, has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts2, 3, 4 and remains of other extinct endemic fauna5, 6, were dated to between about 95 and 12 thousand calendar years (kyr) ago2, 3, 7. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago8, 9, 10. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13–11 kyr cal. BP)1, 2, 3, 7, 11. Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago—potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans12, 13—is an open question.

Link

~40 thousand year old cave art from Indonesia

The BBC website has some nice pictures of it.

Nature 514, 223–227 (09 October 2014) doi:10.1038/nature13422

Pleistocene cave art from Sulawesi, Indonesia

M. Aubert et al.

Archaeologists have long been puzzled by the appearance in Europe ~40–35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces)1, 2 and portable art (for example, carved figurines)3, 4, and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia5, 6, 7, 8, where modern humans (Homo sapiens) were established by 50 kyr ago9, 10. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art11. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa (‘pig-deer’) made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ~40 kyr ago at opposite ends of the Pleistocene Eurasian world.

Link

Indonesian mega-study (Tumonggor et al. 2013)

A new comprehensive survey of Y chromosome/mtDNA variation in Indonesia has just appeared online. From the paper:

The first stage of Indonesian prehistory represents the archipelago’s initial settlement as part of the African dispersal ~50 kya. The geography of the region was then markedly different from today. Sea levels were much lower, most modern islands had merged into larger landmasses, and the westernmost parts of Indonesia were physically contiguous with mainland Asia. This first stage is recorded by deep mtDNA lineages (M17a, M73, M47, N21, N22, R21, R22 and R23), which trace back to the main branching of macrohaplogroups M and N, and have a spotty distribution across both mainland and island southeast Asia today.

and:

The second stage reflects recurrent colonization events from mainland Asia throughout the later Paleolithic. Many haplogroups (B4a, B4b, B4c, B4c1b3, B5a, B5b, B5b1, D and E) show origin dates of 10-40 kya (Supplementary Table 6) 25, 63 and are distributed across a wide range of mainland and island southeast Asian populations. 

and:

The third stage represents Neolithic movements into and around island southeast Asia. Some of these may involve population dispersals from (and perhaps to) Taiwan, while others reflect movements between Indonesian island groups. Representative haplogroups include M7b3, E1a1a, M7c3c and Y2. Autosomal data strongly supports large demic movements of Asian populations into eastern Indonesia from around 4 kya 67.

and, finally:

The fourth stage reflects historic movements into Indonesia, largely involving trade and the associated spread of major religions from India, Arabia and China 71. Although found at relatively low frequency today, Y chromosome lineages representing these movements occur across Indonesia 20, notably in the west, such as the Hindu dominated island of Bali

It would be useful to study Indonesian haplogroups as a means of testing the hypothesis of Indian settlement in Australia, since it is difficult to see any such settlement that would not have passed through the Indonesian archipelago.

Of the lineages found in Indonesia, the deepest ancestry appears to be associated with mtDNA haplogroups P (54+/-16ky) and Q (38+/-9ky), both of which appear to have clear "Australo-Melanesian" associations. Of the B subclades that are lately of interest due to the publication of Tianyuan ancient DNA, the oldest one appears to be B4a (33+/-13ky).

One of the major puzzles in prehistory is the co-occurrence of mtDNA macro-haplogroups M and N in the eastern portion of Eurasia vs. the dominance of N in the western part thereof. The peninsulas of Arabia and India probably hold a key to this riddle, although in both cases the situation is obscured by subsequent events: in Arabia, there has probably been substantial population turnover during its "desert" phases, while in India there has been recent admixture between the aboriginal population and West Eurasian-derived inhabitants.

Journal of Human Genetics , (24 January 2013) | doi:10.1038/jhg.2012.154

The Indonesian archipelago: an ancient genetic highway linking Asia and the Pacific 

Meryanne K Tumonggor et al.

Indonesia, an island nation linking mainland Asia with the Pacific world, hosts a wide range of linguistic, ethnic and genetic diversity. Despite the complexity of this cultural environment, genetic studies in Indonesia remain surprisingly sparse. Here, we report mitochondrial DNA (mtDNA) and associated Y-chromosome diversity for the largest cohort of Indonesians examined to date—2740 individuals from 70 communities spanning 12 islands across the breadth of the Indonesian archipelago. We reconstruct 50 000 years of population movements, from mitochondrial lineages reflecting the very earliest settlers in island southeast Asia, to Neolithic population dispersals. Historic contacts from Chinese, Indians, Arabs and Europeans comprise a noticeable fraction of Y-chromosome variation, but are not reflected in the maternally inherited mtDNA. While this historic immigration favored men, patterns of genetic diversity show that women moved more widely in earlier times. However, measures of population differentiation signal that Indonesian communities are trending away from the matri- or ambilocality of early Austronesian societies toward the more common practice of patrilocal residence today. Such sex-specific dispersal patterns remain even after correcting for the different mutation rates of mtDNA and the Y chromosome. This detailed palimpsest of Indonesian genetic diversity is a direct outcome of the region’s complex history of immigration, transitory migrants and populations that have endured in situ since the region’s first settlement.

Link

Austronesian spread across Indonesia

It is wonderful when different disciplines arrive at the same conclusions independently. Recent work in Austronesian languages by Gray, Drummond, and Greenhill arrived at the conclusion that Austronesian originated in Taiwan c. 5,200 years ago, and experienced a rapid expansion pulse c. 4,000 years ago that resulted in the colonization of island Southeast Asia.

This colonization event left its traces in the genomes of present-day eastern Indonesians; the pre-Austronesian inhabitants of those islands were Papuan-like, or, in terms of traditional physical anthropology Australoid, whereas the expanding Austronesian mariners were Mongoloid. If the expansion happened within the time frame in question, it can be dated by dense genotype data by looking at the relative lengths of Australoid and Mongoloid segments in extant individuals.

This is exactly what a new paper has achieved. It has determined that the "Asian" admixture signal in Eastern Indonesia dates to 4,000-3,000 years ago.

This is what the linguistic analysis by Gray et al. had to say:

It shows an Austronesian origin in Taiwan around 5200 years ago, followed bya settlement pause (pause 1) between 5200 and 4000 years ago. After this pause, a rapid expansion pulse (pulse 1) led to thesettlement of Island Southeast Asia, New Guinea and Near Oceania in less than 1000 years.

which is entirely consistent with the 4,000-3,000 year old colonization of Eastern Indonesia deduced by genetic recombination analysis.

The paper has some brilliant visualizations of information, one of which is reproduced on the left. Notice the cline of Papuan ancestry in Eastern Indonesia, east of the Wallace Line.

From the paper:

These results strongly suggest that the admixture cline in East Indonesia reflects the spread of individuals of Asian ancestry coming from the west and admixing with resident groups of  Papuan ancestry. Second, the time of admixture is highlyconsistent for the two different datasets, which were estimated bytwo different methods, and suggest that the admixture began about 4,000 y ago (Figs. 1E and 2E and Table 3). This time is in excellent agreement with estimates from archaeological and linguistic data for the arrival of Austronesian speakers in East Indonesia about 3,500–4,000 y ago (9, 21). For example, the oldest pottery found in East Indonesia, associated with the Austronesian culture, dates back to 3,500 y ago (22). Moreover , a Bayesian analysis of Austronesian languages dates the Austronesian expansion into Indonesia to about 4,000 y ago and also suggests a west to east spread across East Indonesia (9).

This is a wonderful co-validation of the (once controversial) use of Bayesian phylogenetics in linguistics, and time depth estimation via recombination in genetics, calibrated with "hard" archaeological evidence. It will be great to see the same consensus arrived for other families as well.

PNAS doi: 10.1073/pnas.1118892109

Genetic dating indicates that the Asian–Papuan admixture through Eastern Indonesia corresponds to the Austronesian expansion

Shuhua Xu et al.

Although the Austronesian expansion had a major impact on the languages of Island Southeast Asia, controversy still exists over the genetic impact of this expansion. The coexistence of both Asian and Papuan genetic ancestry in Eastern Indonesia provides a unique opportunity to address this issue. Here, we estimate recombination breakpoints in admixed genomes based on genome-wide SNP data and date the genetic admixture between populations of Asian vs. Papuan ancestry in Eastern Indonesia. Analyses of two genome-wide datasets indicate an eastward progression of the Asian admixture signal in Eastern Indonesia beginning about 4,000–3,000 y ago, which is in excellent agreement with inferences based on Austronesian languages. The average rate of spread of Asian genes in Eastern Indonesia was about 0.9 km/y. Our results indicate that the Austronesian expansion had a strong genetic as well as linguistic impact on Island Southeast Asia, and they significantly advance our understanding of the biological origins of human populations in the Asia–Pacific region.

Link

Homo floresiensis: dramatically dwarfed Homo erectus descendant

Journal of Human Evolution doi:10.1016/j.jhevol.2011.08.008

Craniofacial morphology of Homo floresiensis: Description, taxonomic affinities, and evolutionary implication

Yousuke Kaifu et al.

This paper describes in detail the external morphology of LB1/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored metrically.

The LB1 specimen exhibits a marked reductive trend in its facial skeleton, which is comparable to the H. sapiens condition and is probably associated with reduced masticatory stresses. However, LB1 is craniometrically different from H. sapiens showing an extremely small overall cranial size, and the combination of a primitive low and anteriorly narrow vault shape, a relatively prognathic face, a rounded oval foramen that is greatly separated anteriorly from the carotid canal/jugular foramen, and a unique, tall orbital shape. Whereas the neurocranium of LB1 is as small as that of some Homo habilis specimens, it exhibits laterally expanded parietals, a weak suprameatal crest, a moderately flexed occipital, a marked facial reduction, and many other derived features that characterize post-habilis Homo. Other craniofacial characteristics of LB1 include, for example, a relatively narrow frontal squama with flattened right and left sides, a marked frontal keel, posteriorly divergent temporal lines, a posteriorly flexed anteromedial corner of the mandibular fossa, a bulbous lateral end of the supraorbital torus, and a forward protruding maxillary body with a distinct infraorbital sulcus. LB1 is most similar to early Javanese Homo erectus from Sangiran and Trinil in these and other aspects. We conclude that the craniofacial morphology of LB1 is consistent with the hypothesis that H. floresiensis evolved from early Javanese H. erectus with dramatic island dwarfism. However, further field discoveries of early hominin skeletal remains from Flores and detailed analyses of the finds are needed to understand the evolutionary history of this endemic hominin species.

Link

Homo erectus soloensis fades into the past...

Every year or so there seems to be a redating of a key fossil in human evolution. It's nice to see scientific self-correction in action, and soon after Neandertals got a little older, casting doubt on their supposedly long co-existence with modern humans, we now have a redating of Homo erectus soloensis from Java to about 150-550 thousand years ago, but certainly long before there were any anatomically modern humans in the area.

PLoS ONE 6(6): e21562. doi:10.1371/journal.pone.0021562

The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

Etty Indriati et al.

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted.

Link

Austronesians in Nias

Mol Biol Evol (2010) doi: 10.1093/molbev/msq300

Unexpected island effects at an extreme: reduced Y-chromosome and mitochondrial DNA diversity in Nias

Mannis van Oven et al.

The amount of genetic diversity in a population is determined by demographic and selection events in its history. Human populations which exhibit greatly reduced overall genetic diversity, presumably resulting from severe bottlenecks or founder events, are particularly interesting, not least because of their potential to serve as valuable resources for health studies. Here, we present an unexpected case, the human population of Nias Island in Indonesia, that exhibits severely reduced Y chromosome (NRY) and to a lesser extent also reduced mitochondrial (mt)DNA diversity as compared with most other populations from the Asia / Oceania region. Our genetic data, collected from more than 400 individuals from across the island, suggest a strong, previously undetected bottleneck or founder event in the human population history of Nias, more pronounced for males than for females, followed by subsequent genetic isolation. Our findings are unexpected given the island's geographic proximity to the genetically highly diverse Southeast Asian world, as well as our previous knowledge about the human history of Nias. Furthermore, all NRY and virtually all mtDNA haplogroups observed in Nias can be attributed to the Austronesian expansion, in line with linguistic data, and in contrast with archaeological evidence for a pre-Austronesian occupation of Nias that, as we show here, left no significant genetic footprints in the contemporary population. Our work underlines the importance of human genetic diversity studies not only for a better understanding of human population history, but also because of the potential relevance for genetic disease mapping studies.

Link

More on geographical divide between Asian and Melanesian types in Indonesia (Cox et al. 2010)

I had previously posted about a paper showing a sharp divide in Indonesia between "Asian" and "Melanesian" Y chromosomes. A reader alerts me to another paper from this year, which discovers this divide using autosomal and X chromosome polymorphisms.

From the paper:

this transition is shifted eastward relative to Wallace’s line—a boundary that separates the biogeographic regions of Asia and Wallacea. At its southern limit, Wallace’s line falls between the islands of Bali and Lombok (figure 1), which are separated by a deep-water sea channel that marks the southern edge of the Sunda
Shelf. During ice-age glacial advances, the Sunda land mass included Borneo, Bali, Java and Sumatra, together with mainland Southeast Asia. However, even in periods
of low sea level, deep water in Wallacea separated the Sunda shelf from the eastern landmass of Sahul (connecting New Guinea and Australia). While the distribution of
many flora and fauna conforms to Wallace’s line, the seafaring capabilities of human settlers to this region undoubtedly overcame this barrier to dispersal. Indeed, Asian ancestry exceeds 50 per cent as far east as the island of Alor, which is well within Wallacea and approximately 1000 km east of Bali, as well as on the island of Sulawesi, which is located east of Wallace’s line in the north (figure 1). Curiously, Wallace himself noted this difference, positing a second line in eastern Indonesia corresponding to changes in human phenotype (Wallace 1869; Cox 2008). Wallace’s second ‘phenotypic’ line broadly parallels the rapid decline in Asian admixture identified here. It is refreshing to see (for once) a paper which acknowledges that modern genetics did not discover the wheel but has to a large extent confirmed what previous generations of scientists, working with their eyes (and later their calipers) could plainly see.

A visually interesting figure from the paper illustrates what a "cline" actually is.

We can see how west of 120 degrees longitude there is a uniform area of Asian ancestry, then a sharp transition zone and then a fairly uniform area of Melanesian ancestry.

The above figure illustrates one of the arguments of those (like me) who assert that racial variation in humans is real: the fact that it geographically punctuated (no smooth cline). The smooth areas of uniformity east/west of 120deg deserve to be recognized as real entities.

For visual illustration, three examples from Deniker's The races of man: a New Caledonian woman representing an "eastern" Melanesian type, a group of people from Flores (where, according to the current paper Asian admixture runs at 62%), and finally a Javan man representing a "western" Indonesian Mongoloid type.

Proc. R. Soc. B (2010) 277, 1589–1596

doi:10.1098/rspb.2009.2041

Autosomal and X-linked single nucleotide polymorphisms reveal a steep Asian–Melanesian ancestry cline in eastern Indonesia and a sex bias in admixture rates

Murray P. Cox

Abstract

The geographical region between mainland Asia and New Guinea is characterized by numerous small islands with isolated human populations. Phenotypically, groups in the west are similar to their neighbours in mainland Southeast Asia, eastern groups near New Guinea are similar to Melanesians, and intervening populations are intermediate in appearance. A long-standing question is whether this pattern primarily reflects mixing between groups with distinct origins or whether natural selection has shaped this range of variation by acting differentially on populations across the region. To address this question, we genotyped a set of 37 single nucleotide polymorphisms that are evolutionarily independent, putatively neutral and highly informative for Asian–Melanesian ancestry in 1430 individuals from 60 populations spanning mainland Asia to Melanesia. Admixture analysis reveals a sharp transition from Asian to Melanesian genetic variants over a narrow geographical region in eastern Indonesia. Interestingly, this admixture cline roughly corresponds to the human phenotypic boundary noted by Alfred Russell Wallace in 1869. We conclude that this phenotypic gradient probably reflects mixing of two long-separated ancestral source populations—one descended from the initial Melanesian-like inhabitants of the region, and the other related to Asian groups that immigrated during the Paleolithic and/or with the spread of agriculture. A higher frequency of Asian X-linked markers relative to autosomal markers throughout the transition zone suggests that the admixture process was sex-biased, either favouring a westward expansion of patrilocal Melanesian groups or an eastward expansion of matrilocal Asian immigrants. The matrilocal marriage practices that dominated early Austronesian societies may be one factor contributing to this observed sex bias in admixture rates.

Link

Major East-West divide in Indonesian Y chromosomes

As usual I have my reservations about the time estimates in this paper, but it is very useful as a guide to genetic variation in Indonesia, an island nation of composite origins where the indigenous population forms part of the S/SE Asia/Oceania zone of "Australoids", probably reflecting early out-of-Africa humans taking the southern route, while this population has been influenced by movements from the north: Caucasoids into India, and Mongoloids or Mongoloid-influenced people into Indonesia.

Getting back to the ever-present time issue; the inferences on this paper are, of course, based on assumption about Y-STR diversity accumulation that I have criticized elsewhere and I will not repeat.

But, isn't it strange that the authors claim a Paleolithic gene pool, while, at the same time, discovering a sharp divide? Common sense dictates that genetic distinctions across a long time span would be blurred, and there would be no sharp divide.

Sharp divides are created by recent population movements and are maintained by insurmountable geographical barriers (e.g., the Sahara or the Pacific) that persist for a long-time.

Molecular Biology and Evolution, doi:10.1093/molbev/msq063

Major East-West Division Underlies Y Chromosome Stratification Across Indonesia

Tatiana M. Karafet et al.

Abstract

The early history of Island Southeast Asia is often characterized as the story of two major population dispersals: the initial Paleolithic colonization of Sahul 45 thousand years ago and the much later Neolithic expansion of Austronesian-speaking farmers 4,000 years ago. Here, in the largest survey of Indonesian Y chromosomes to date, we present evidence for multiple genetic strata that likely arose through a series of distinct migratory processes. We genotype an extensive battery of Y chromosome markers, including 85 SNPs/indels and 12 Y-STRs, in a sample of 1,917 men from 32 communities located across Indonesia. We find that the paternal gene pool is sharply subdivided between western and eastern locations, with a boundary running between the islands of Bali and Flores. Analysis of molecular variance reveals one of the highest levels of between-group variance yet reported for human Y chromosome data (e.g., ?ST = 0.47). Eastern Y chromosome haplogroups are closely related to Melanesian lineages (i.e., within the C, M and S subclades) and likely reflect the initial wave of colonization of the region, while the majority of western Y chromosomes (i.e., O-M119*, O-P203, and O-M95*) are related to haplogroups that may have entered Indonesia during the Paleolithic from mainland Asia. In addition, two novel markers (P201, P203) provide significantly enhanced phylogenetic resolution of two key haplogroups (O-M122, O-M119) that are often associated with the Austronesian expansion. This more refined picture leads us to put forward a four-phase colonization model in which Paleolithic migrations of hunter-gatherers shape the primary structure of current Indonesian Y chromosome diversity, and Neolithic incursions make only a minor impact on the paternal gene pool, despite the large cultural impact of the Austronesian expansion.

Link

Mapping Human Genetic Diversity in Asia

From the press release:

Several genome-wide studies of human genetic diversity have been conducted on European populations. Now, for the first time, these studies have been extended to 73 Southeast Asian (SEA) and East Asian (EA) populations.

In a paper titled, "Mapping Human Genetic Diversity in Asia," published online Science on 10 Dec. 2009, over 90 scientists from the Human Genome Organisation's (HUGO's) Pan-Asian SNP Consortium report that their study conducted within and between the different populations in the Asia continent showed that genetic ancestry was highly correlated with ethnic and linguistic groups.

The scientists also reported a clear increase in genetic diversity from northern to southern latitudes. Their findings also suggest that there was one major inflow of human migration into Asia arising from Southeast Asia, rather than multiple inflows from both southern and northern routes as previously proposed. This indicates that Southeast Asia was the major geographic source of East Asian and North Asian populations.

(A figure illustrating the paper shows plausible routes of pre-historical migration of Asian human populations. According to the study, the PanAsia SNP Initiative, the most recent common ancestors of Asians arrived first in India and later, some of them migrated to Thailand, and South to the lands known today as Malaysia, Indonesia, and the Philippines. The first group of settlers must have gone very far south before they settled successfully. These included the Malay Negritos , Philippine Negritos , the East Indonesians, and early settlers of the Pacific Islands. Thereafter, one or several groups of people migrated North, mixed with previous settlers there and, finally, formed various populations we now refer to as Austronesian, Austro-Asiatic, Tai-Kadai, Hmong-Mien, and Altaic. The figure is titled, "Putative Pre-Historical Migration Routes of Asian Human Populations.")

The researchers noted that the geographical and linguistic basis of genetic subgroups in Asia clarifies the need for genetic stratification when conducting genetic and pharmacogenomic studies in this continent, and that human genetic mapping of Asia has important implications for the study of genetics and disease and for research to understand migratory patterns in human history.

HUGO President Edison Liu, M.D., who is Executive Director of the Genome Institute of Singapore (GIS), said, "This study was a milestone not only in the science that emerged, but the consortium that was formed. Ten Asian countries came together in the spirit of solidarity to understand how we were related as a people, and we finished with a truly Asian scientific community. We overcame shortage of funds and diverse operational constraints through partnerships, good will, and cultural sensitivity.

"Our next goal is to expand this collaboration to all of Asia including Central Asia and the Polynesian Islands," said Dr. Liu, one of the corresponding authors of the paper. "We also aim to be more detailed in our genomic analysis and plan to include structural variations, as well as over a million single nucleotide polymorphisms in the next analysis."

While HUGO initiated and coordinated the research, Dr. Liu pointed out, "Affymetrix, led by Dr. Giulia C. Kennedy and based in the US, is our primary technology partner in this endeavour. We greatly appreciate their support."

As usual for a Science paper there are voluminous (and free) supplementary materials. The Neighbor-Joining tree shows the clear correlation between linguistic affiliation and genetic identity of individuals.


UPDATE: As to the main thesis of the paper, namely that East Asians are descended from Southeast Asians rather than Central Asians, I have to say that I am not convinced. This thesis is based on two observations: minimum sharing between East Asians and Central/South Asians and south-north reduction of genetic diversity in East Eurasians. However, the high genetic diversity in Southeast Asians can be explained if they are taken to be old hybrids of Mongoloid northerners with "Australoid"-like southerners as physical anthropology suggests, and the seeming absence of influence of present-day Central/South Asians is due to the fact that the latter are largely Caucasoids of western Eurasian origin, and, thus, do not represent any putative ancestral populations to modern Mongoloids.

Science doi:10.1126/science.1177074

Mapping Human Genetic Diversity in Asia

The HUGO Pan-Asian SNP Consortium

Abstract

Asia harbors substantial cultural and linguistic diversity, but the geographic structure of genetic variation across the continent remains enigmatic. Here we report a large-scale survey of autosomal variation from a broad geographic sample of Asian human populations. Our results show that genetic ancestry is strongly correlated with linguistic affiliations as well as geography. Most populations show relatedness within ethnic/linguistic groups, despite prevalent gene flow among populations. More than 90% of East Asian (EA) haplotypes could be found in either Southeast Asian (SEA) or Central-South Asian (CSA) populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50% of EA haplotypes were found in SEA only and 5% were found in CSA only, indicating that SEA was a major geographic source of EA populations.

Link

Genetic methods applied to linguistic diversity of the Sahul

It is great to see cross-pollination between the sciences; in this case, use of STRUCTURE has led to insights about languages of the Sahul.

From the paper:

Although we cannot specify how many different migrations have colonized Sahul since the first settlement approximately 50,000 years ago, our results indicate ancient splits into seven major plausible groups: TNG, South-Papuan, North-West Papuan, North-East Papuan, West-Papuan, PN, and non-PN. The wide-spread families (TNG and PN) on both sides of the Torres Strait divide (~9,000 BP) are the result of more recent expansions of two of those groups, in the case of TNG probably linked to the development of agriculture, ~9,000 to 6,000 years ago, see [35],[37].

The AN expansion is much more recent and has only had effects in eastern Indonesia, along the north coast of New Guinea and the islands east of the New Guinea mainland. We know on the basis of the comparative method correlated with archaeological data that approximately 3,200 years ago the Oceanic subgroup dispersed from its homeland on New Britain in three directions [9]: (1) back along the north coast, (2) around the eastern tip of New Guinea along the south coast, and (3) much further into the Pacific. The results of our analysis capture some of the impact of this great expansion on the languages that were already in the region. We find that in the eastern islands there are clearly distinct AN and non-AN groups, with good evidence of a deep structural phylogenetic signal, albeit with some admixture [16]. In the western islands however there is considerably more typological convergence between AN and non-AN languages (see also [38]). The linguistic population identified as Red appears to have members along the north coast (Mairasi, I'saka, and Kamasau) and on New Britain, where again both AN (Mangseng) and Papuan languages (Kol and Sulka) have contributions from the same cluster. This finding suggests an area of millennia of contact between AN and Papuan non-TNG speaking groups.

Gene Expression has more.

PLoS Biology doi:10.1371/journal.pbio.1000241

Explaining the Linguistic Diversity of Sahul Using Population Models


Ger Reesink et al.

Abstract

The region of the ancient Sahul continent (present day Australia and New Guinea, and surrounding islands) is home to extreme linguistic diversity. Even apart from the huge Austronesian language family, which spread into the area after the breakup of the Sahul continent in the Holocene, there are hundreds of languages from many apparently unrelated families. On each of the subcontinents, the generally accepted classification recognizes one large, widespread family and a number of unrelatable smaller families. If these language families are related to each other, it is at a depth which is inaccessible to standard linguistic methods. We have inferred the history of structural characteristics of these languages under an admixture model, using a Bayesian algorithm originally developed to discover populations on the basis of recombining genetic markers. This analysis identifies 10 ancestral language populations, some of which can be identified with clearly defined phylogenetic groups. The results also show traces of early dispersals, including hints at ancient connections between Australian languages and some Papuan groups (long hypothesized, never before demonstrated). Systematic language contact effects between members of big phylogenetic groups are also detected, which can in some cases be identified with a diffusional or substrate signal. Most interestingly, however, there remains striking evidence of a phylogenetic signal, with many languages showing negligible amounts of admixture.

Link

Genetic ancestry of Coloured South Africans

Hum Mol Genet. 2009

Genetic structure of a unique admixed population: implications for medical research.

Patterson N, Petersen DC, van der Ross RE, Sudoyo H, Glashoff RH, Marzuki S, Reich D, Hayes VM.

Understanding human genetic structure has fundamental implications for understanding the evolution and impact of human diseases. In this study we describe the complex genetic substructure of a unique and recently admixed population arising approximately 350 years ago as a direct result of European settlement in South Africa. Analysis was performed using over 900,000 genome-wide single nucleotide polymorphisms in 20 unrelated ancestry-informative marker selected Coloured individuals and made comparisons with historically predicted founder populations. We show that there is substantial genetic contribution from at least four distinct population groups: Europeans, South Asians, Indonesians, and a population genetically close to the isiXhosa sub-Saharan Bantu. This is in good accord with the historical record. We briefly examine the implications of determining the genetic diversity of this population, not only for furthering understanding of human evolution out of Africa, but also for genome-wide association studies using admixture mapping. In conclusion, we define the genetic structure of a uniquely admixed population that holds great potential to advance genetic-based medical research.

Link

Archaic admixture in modern humans? (Wall et al. 2009)

John Hawks points me towards a new paper which aims to estimate the presence of archaic admixture (from Neandertals, Indonesian "hobbits", and assorted candidates) in the modern human genome. I highly recommend reading that post for an analysis of the paper; while Dr. Hawks is probably on the "admixture happened" side of the debate, he offers both reasons to like and dislike the new study.

There is, however, what I think is a more important weakness of the paper. To substantiate the case for admixture, the authors compare West African Yorubans separately with Europeans and with East Asians.

Let's assume that they do in fact detect what is genuine archaic admixture, i.e., the introgression of chunks of DNA into regional humans from a species other than modern Homo sapiens. They can achieve this by detecting regions where Yoruban DNA sequence differs from European DNA sequence in a manner suggestive of a very ancient time depth.

But, is there a reason to ascribe these differences to Neandertal introgression?

Actually, there is not, as Europeans are derived from a specific East African population: they are not derived from Sub-Saharan Africans in general, or West Africans in particular. Indeed, this very paper finds evidence of archaic admixture in Africa itself!

Thus, what appears as a piece of Neandertal DNA in Europeans, could in fact be a piece of ancestral East African DNA which differs from Yoruba DNA because of population structure in Africa itself, for which there is more than enough evidence.

So, what this paper does, is tell us that a chunk of DNA in Europeans, and the corresponding chunk in Yorubans don't share ancestry within a conventional Out-of-Africa time frame. It does not, however, tell us that this is because of archaic introgression in Europeans. The culprit could equally well be long-term population structure in Africa, i.e., the presence of "modern" and "archaic" populations in Africa itself.

The way forward is to compare Europeans with Middle Eastern Caucasoids and East Africans. If the "archaic" European DNA is found across many of these populations, then the case for Neandertal introgression will weaken, and the hypothesis presented in this post (ancient African population structure) will be supported.

UPDATE (May 9): John Hawks has updated his blog entry in response to this post. He makes two points:

The East Asian and European comparisons come up with different genes showing evidence of putative introgression.

What we don't know at this point is whether either (or both) of the European/East Asian introgression candidate genes are found in East Africa. If so, then the presence of different sets of genes in Europe and East Asia could be the result of random survivals of the diversity of the initial African population. Or, introgression happened in either Europe or East Asia, and one region preserves archaic DNA inherited from Africa and the other archaic DNA that introgressed in East Asia or Europe, which is why the two are different.

Furthermore, while Out-of-Africa is conventionally seen as one migration c. 40Kya which eventually spawned both Europeans and East Asians, there is Y-chromosomal evidence for a separate process linking Western Eurasia and East Africa (Y-chromosome haplogroup E). Thus, a later movement may have spread "archaic" East African genes into Western Eurasia but not in East Asia.

John's second point:

The entire point of the out-of-Africa replacement idea is to draw humans from an unstructured ancient population. Humans have to be inbred to explain the low genetic variation today. A long bottleneck in Africa is one explanation for this inbreeding

We do know that there was substantial variation in Africa at the time when modern Homo sapiens emerged. A long period of inbreeding in Africa would indeed create the fairly homogeneous species we discover when we look at most genes. This species would, however, during its population expansion -within Africa- come into contact with other previously isolated African populations, some of which would go extinct, while others might be absorbed, their genes persisting at low frequency in the expanding species.

This requires no great leap of faith. It parallels directly what happened in Africa in the last few thousand years, where previously isolated Pygmy and Khoi-San populations came into contact with expanding farmer-pastoralists, and contributing a little bit to the farmers' genomes.

Thus, the expanding African population that eventually spilled over into Eurasia, would indeed be quite inbred and homogeneous, but its gene pool would also contain traces of the smaller, less successful African populations it had absorbed. Because of their low frequency, these traces would be more susceptible to extinction in the series of bottlenecks that led to Europeans on one side and East Asians on the other, with different sets of archaic genes preserved in either region.


Molecular Biology and Evolution, doi:10.1093/molbev/msp096

Detecting ancient admixture and estimating demographic parameters in multiple human populations

Jeffrey D. Wall et al.

Abstract

We analyze patterns of genetic variation in extant human polymorphism data from the NIEHS SNPs project to estimate human demographic parameters. We update our previous work by considering a larger data set (more genes and more populations), and by explicitly estimating the amount of putative admixture between modern humans and archaic human groups (e.g., Neandertals, Homo erectus, H. floresiensis). We find evidence for this ancient admixture in European, East Asian and West African samples, suggesting that admixture between diverged hominin groups may be a general feature of recent human evolution.

Link

Genetic admixture in eastern Indonesia

From the paper:

Although less pronounced in EI compared to other regions, we observed a higher eastern Asian component with mtDNA than with NRY-DNA, and conversely a higher Melanesian component with NRY-DNA than with mtDNA in EI, similar to what has been described for Island Melanesia (Kayser et al. 2008) and Polynesia (Kayser et al. 2006). As described elsewhere, a history of sex-biased admixture between Austronesians and non- Austronesians might explain this result, confirming previous surveys in Near and Remote Oceania on the modality of the Austronesian migration (Hage and Marck 2003; Kayser et al. 2006; Kayser et al. 2008; Kayser, Lao, and Stoneking 2008).

Molecular Biology and Evolution, doi:10.1093/molbev/msp097

Genetic admixture history of eastern Indonesia as revealed by Y-chromosome and mitochondrial DNA analysis

Stefano Mona et al.

Abstract

Eastern Indonesia possesses more linguistic diversity than any other region in Southeast Asia, with both Austronesian (AN) languages that are of East Asian origin, as well as non-Austronesian (NAN) languages of likely Melanesian origin. Here, we investigated the genetic history of human populations from seven eastern Indonesian islands, including AN- and NAN-speakers, as well as the relationship between languages and genes, by means of non-recombining Y-chromosomal (NRY) and mitochondrial DNA (mtDNA) analysis. We found that the eastern Indonesian gene pool consists of East Asian as well as Melanesian components, as might be expected based on linguistic evidence, but also harbours putative indigenous eastern Indonesian signatures that perhaps reflect the initial occupation of the Wallacea by aboriginal hunter-gatherers already in Palaeolithic times. Furthermore, both NRY and mtDNA data showed a complete lack of correlation between linguistic and genetic relationships, most likely reflecting genetic admixture and/or language shift. In addition, we noted a small fraction of the NRY and mtDNA data shared between eastern Indonesians and Australian Aborigines likely reflecting an ancient link between Asia and Australia. Our data thus provide insights into the complex genetic ancestry history of eastern Indonesian islanders characterized by several admixture episodes, and demonstrate a clear example of the lack of the often-assumed correlation between the genes and languages of human populations.

Link

Paternal genetic affinity between western Austronesians and Daic populations

BMC Evol Biol. 2008 May 15;8(1):146.

Paternal genetic affinity between western Austronesians and Daic populations.

Li H, Wen B, Chen SJ, Su B, Pramoonjago P, Liu Y, Pan S, Qin Z, Liu W, Cheng X, Yang N, Li X, Tran D, Lu D, Hsu MT, Deka R, Marzuki S, Tan CC, Jin L.

ABSTRACT: BACKGROUND: Austronesian is a linguistic family spread in most areas of the Southeast Asia, the Pacific Ocean, and the Indian Ocean. Based on their linguistic similarity, this linguistic family included Malayo-Polynesians and Taiwan aborigines. The linguistic similarity also led to the controversial hypothesis that Taiwan is the homeland of all the Malayo-Polynesians, a hypothesis that has been debated by ethnologists, linguists, archaeologists, and geneticists. It is well accepted that the Eastern Austronesians (Micronesians and Polynesians) derived from the Western Austronesians (Island Southeast Asians and Taiwanese), and that the Daic populations on the mainland are supposed to be the headstream of all the Austronesian populations. RESULTS: In this report, we studied 20 SNPs and 7 STRs in the non-recombining region of the 1,509 Y chromosomes from 30 China Daic populations, 23 Indonesian and Vietnam Malayo-Polynesian populations, and 11 Taiwan aboriginal populations. These three groups show many resemblances in paternal lineages. Admixture analyses demonstrated that the Daic populations are hardly influenced by Han Chinese genetically, and that they make up the largest proportion of Indonesians. Most of the population samples contain a high frequency of haplogroup O1a-M119, which is nearly absent in other ethnic families. The STR network of haplogroup O1a* illustrated that Indonesian lineages did not derive from Taiwan aborigines as linguistic studies suggest, but from Daic populations. CONCLUSION: We show that, in contrast to the Taiwan homeland hypothesis, the Island Southeast Asians do not have a Taiwan origin based on their paternal lineages. Furthermore, we show that both Taiwan aborigines and Indonesians likely derived from the Daic populations based on their paternal lineages. These two populations seem to have evolved independently of each other. Our results indicate that a super-phylum, which includes Taiwan aborigines, Daic, and Malayo-Polynesians, is genetically educible.

Link

New Y-chromosome haplogroup tree

UPDATE (Apr 2):

The report is now online. Unfortunately, the supplementary information is not yet online.

UPDATE 2:

I think that the Genographic Project has a lot of rewriting to do in their Atlas of the Human Journey given the proposed dates for the major haplogroups. For example, the oft-repeated claim that R1b has something to do with the Cro-Magnons is no longer tenable.

UPDATE 3:

The supplementary material can be found here (pdf).

Genome Research DOI: 10.1101/gr.7172008

New binary polymorphisms reshape and increase resolution of the human Y chromosomal haplogroup tree

Tatiana M. Karafet et al.

Markers on the non-recombining portion of the human Y chromosome continue to have applications in many fields including evolutionary biology, forensics, medical genetics, and genealogical reconstruction. In 2002, the Y Chromosome Consortium published a single parsimony tree showing the relationships among 153 haplogroups based on 243 binary markers and devised a standardized nomenclature system to name lineages nested within this tree. Here we present an extensively revised Y chromosome tree containing 311 distinct haplogroups, including two new major haplogroups (S and T), and incorporating approximately 600 binary markers. We describe major changes in the topology of the parsimony tree and provide names for new and rearranged lineages within the tree following the rules presented by the Y Chromosome Consortium in 2002. Several changes in the tree topology have important implications for studies of human ancestry. We also present demography-independent age estimates for 11 of the major clades in the new Y chromosome tree.

Link

A new Y-chromosome haplogroup tree will be published in Genome Research. Here is the public release:

The Y chromosome retains a remarkable record of human ancestry, since it is passed directly from father to son. In an article published online today in Genome Research (www.genome.org), scientists have utilized recently described genetic variations on the part of the Y chromosome that does not undergo recombination to significantly update and refine the Y chromosome haplogroup tree. The print version of this work will appear in the May issue of Genome Research, accompanied by a special poster of the new tree.

...

Hammer’s group integrated more than 300 new markers into the tree, which allowed the resolution of many features that were not yet discernable, as well as the revision of previous arrangements. “The major lineages within the most common African haplogroup, E, are now all sorted out, with the topology providing new interpretations on the geographical origin of ancient sub-clades,” describes Hammer. “When one polymorphism formerly described as unique, but recently shown to have reversed was replaced by recently reported markers, a sub-haplogroup of haplogroup O, the most common in China, was considerably rearranged,” explains Fernando Mendez, a co-author of the study.

In addition to improving the resolution of branches, the latest reconstruction of the tree allows estimates of time to the most recent common ancestor of several haplogroups. “The age of [haplogroup] DE is about 65,000 years, just a bit younger than the other major lineage to leave Africa, which is assumed to be about 70,000 years old,” says Hammer, describing an example of the fine resolution of age that is now possible. “Haplogroup E is older than previously estimated, originating approximately 50,000 years ago.”

Furthermore, Hammer explains that this work has resulted in the addition of two new major haplogroups, S and T, with novel insights into the ancestry of both. “Haplogroup T, the clade that Thomas Jefferson’s Y chromosome belongs to, has a Middle Eastern affinity, while haplogroup S is found in Indonesia and Oceania.”

News on Arabian mtDNA

Not one but two recent paper on Arabian mtDNA, giving us a better idea of its geographical structure. I am not sure what to make of the assertion in the first paper that the Arabian peninsula has been the recipient of genetic input from Australia; well, it's in an open access journal so you can form your own opinions.

BMC Evol Biol. 2008 Feb 12;8(1):45 [Epub ahead of print]

Mitochondrial DNA structure in the Arabian Peninsula.

Abu-Amero KK, Larruga JM, Cabrera VM, Gonzalez AM.

ABSTRACT: BACKGROUND: Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA) molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3. RESULTS: To assess the role of the Arabian Peninsula in the southern route, we genetically analyzed 553 Saudi Arabs using partial (546) and complete mtDNA (7) sequencing, and compared the lineages obtained with those present in Africa, the Near East, central, east and southeast Asia and Australasia. The results showed that the Arabian Peninsula has received substantial gene flow from Africa (20%), detected by the presence of L, M1 and U6 lineages; that an 18% of the Arabian Peninsula lineages have a clear eastern provenance, mainly represented by U lineages; but also by Indian M lineages and rare M links with Central Asia, Indonesia and even Australia. However, the bulk (62%) of the Arabian lineages has a Northern source. CONCLUSIONS: Although there is evidence of Neolithic and more recent expansions in the Arabian Peninsula, mainly detected by (preHV)1 and J1b lineages, the lack of primitive autochthonous M and N sequences, suggests that this area has been more a receptor of human migrations, including historic ones, from Africa, India, Indonesia and even Australia, than a demographic expansion center along the proposed southern coastal route.

Link

Am J Phys Anthropol. 2008 Feb 6 [Epub ahead of print]

Regional differences in the distribution of the sub-Saharan, West Eurasian, and South Asian mtDNA lineages in Yemen.

Cerný V et al.

Despite its key location for population movements out of and back into Africa, Yemen has not yet been sampled on a regional level for an investigation of sub-Saharan, West Eurasian, and South Asian genetic contributions. In this study, we present mitochondrial DNA (mtDNA) data for regionally distinct Yemeni populations that reveal different distributions of mtDNA lineages. An extensive database of mtDNA sequences from North and East African, Middle Eastern and Indian populations was analyzed to provide a context for the regional Yemeni mtDNA datasets. The groups of western Yemen appear to be most closely related to Middle Eastern and North African populations, while the eastern Yemeni population from Hadramawt is most closely related to East Africa. Furthermore, haplotype matches with Africa are almost exclusively confined to West Eurasian R0a haplogroup in southwestern Yemen, although more sub-Saharan L-type matches appear in more northern Yemeni populations. In fact, Yemeni populations have the highest frequency of R0a haplotypes detected to date, thus Yemen or southern Arabia may be the site of the initial expansion of this haplogroup. Whereas two variants of the sub-Saharan haplogroup M1 were detected only in southwestern Yemen close to the Bab el-Mandeb Strait, different non-African M haplotypes were detected at low frequencies ( approximately 2%) in western parts of the country and at a higher frequency (7.5%) in the Hadramawt. We conclude that the Yemeni gene pool is highly stratified both regionally and temporally and that it has received West Eurasian, Northeast African, and South Asian gene flow.

Link

AAPA 2007 abstracts

The 2007 meeting of the American Association of Physical Anthropologists will be held in about a month. As in previous years, here are some interesting abstracts to be presented at the meeting (pdf).

(up to page 94)

Homo floresiensis Cranial and Mandibular Morphology
J.Y. Anderson, University of New Mexico
These results suggest the Flores material does not represent a population derived from Australomelanesians, and do not represent a non-pathological dwarfed population of Homo sapiens. These results do not completely rule out a representation of a microcephalic dwarfed population, at the same time it is suggested possible affinities to earlier hominin groups is equally parsimonious.

Do Qafzeh and Skhūl represent the ancestors of Upper Paleolithic modern humans? A dental perspective.
S.E. Bailey et al.
If these fossils represent the source of early Upper Paleolithic people, there is no need to invoke admixture with Neandertals to explain archaic dental features observed in some early Upper Paleolithic humans.

Ancient Cemetery Social Patterning Project: Ancient DNA in Tirup Cemetery.
L.E. Baker et al.

Reconstructing the settlement history of the central Andes from mitochondrial DNA analyses.
K. Batai et al.
We found that among central Andean ancient and modern population samples, haplogroup B frequencies increased through time, while haplogroup A frequencies declined. At this point, we do not yet have sufficient data to determine whether these patterns indicate different population histories between ancient coastal and modern highland populations, or a larger temporal trend in entire central Andes region

Analysis of Genetic Diversity in Ethnic Populations of Afghanistan
P. Bermudez et al.
The Middle East has the distinction of being a major crossroads of human migration. The genetic diversity of Afghanistan, however, has long remained a missing piece to this rich and complex puzzle. To explore both the diversity within Afghanistan and to understand the relative genetic contributions from various groups throughout the Eurasian continent, buccal swabs were collected from 252 unrelated Afghani men for mitochondrial DNA analysis. Each of these men hailed from
one of four major ethnic groups inhabiting the region: the Pashtun, Hazara, Tajik or
Nooristani. The Indo-Iranian speaking Pashtun represent the largest ethnic group in Afghanistan; the Tajiks have a complex genetic history that likely involves admixture between Turkic groups and smaller distinct ethnic groups within Afghanistan; the Hazara, on the other hand, are thought to represent remnants of Ghengis Khan’s army left behind as it expanded through Asia; and the Nooristani have biological links to populations in northern Pakistan and the
claim of descent from Alexander the Great’s army. All samples were analyzed for HVS1
and SNP variation. In all of these populations, Western Eurasian haplogroups (H, HV, R, J, I, U, X) were most common, with the highest frequency occurring in the Nooristanis, while the remaining East Eurasian haplogroups including D, G, and various other M types. The results of this study will be instrumental in expanding our knowledge of Afghani genetic history, in addition to broadening our understanding of population migrations throughout West and Central Asia.

Dental variation in Holocene Khoesan populations.
W. Black et al.

Are the Koh an indigenous population of the Hindu Kush? II: a dental morphology investigation.

S. Blaylock and B.E. Hemphill

Little is known about the population history of the ethnic groups in Chitral District, Pakistan, an area long been regarded as the “crossroads of Asia.” Some scholars emphasize that the Koh lifeway is the consequence of long-standing indigenous isolation. Others stress the equestrian
tradition among Koh villagers indicate they are descendants of Central Asians who emigrated across the Hindu Kush Mountains during the second millennium BC. To still others, an array of Persian linguistic inclusions indicates the Koh are more recent emigrants from the Iranian Plateau. This investigation tests these hypotheses for Koh origins through assessment of dental
morphology variations of the permanent dentition scored as 17 tooth-trait combination in accordance with the Arizona State University Dental Morphology System in a sample of 134 Kho school children from Chitral City. These data were contrasted with 17 additional samples. Comparisons are in two stages and include cluster analysis, multidimensional scaling and principal coordinates analysis. First, sex-pooled and sex-specific data compared Koh to six contemporary ethnic groups from India. Results indicate the Koh share equidistant affinities to Indo-European speaking west-Central Indian and Dravidianspeaking South Indian ethnic groups.
Second, sex-pooled data compared the Koh to 13 prehistoric samples from Neolithic to Early Iron Age sites located in the Indus Valley, Central Asia and the Iranian Plateau. Results indicate that the Koh share little affinity to prehistoric Indus Valley groups. Rather, the Koh share nearly equal affinities to prehistoric inhabitants of the Iranian Plateau and Central Asia.

A Howells grasp on prehistoric and recent Japan: A precursor to the Kennewick connection.
C. L. Brace, N. Seguchi.
Using many more samples, our results are compatible with what Howells showed for his Japanese comparisons, and,using the neighbor-joining technique, we can go on to show that Kennewick ties with the Ainu who are the descendants of the Jōmon.The Jōmon then are the probable ancestors of
the first inhabitants of the western hemisphere.

Admixture in Mexico City: implications for admixture mapping.
E. Cameron et al.
"The average proportions of Native American, European and West African admixture were estimated as 65%, 30% and 5% respectively."

"In a logistic model with higher educational status as dependent variable, the odds ratio for higher educational status associated with an increase from 0 to 1 in European admixture proportions was 9.4 (95% credible interval 3.8 – 22.6). This association of socioeconomic status with individual admixture proportion shows that genetic stratification in this population is
paralleled, and possibly maintained, by socioeconomic stratification."

Intracontinental Distribution of Haplotype Variation: Implications for Human Demographic History.
M.C. Campbell et al.
"These results suggest that diverse African populations were more subdivided with lower levels of gene flow during human history."

Social stratification in a Christian cemetery? An assessment of stress indicators and social status at Anglo-Saxon Raunds.
E.F. Craig, J.L. Buckberry
"The occurrence of statistically more individuals with both cribra orbitalia and tibial periostitis in plain graves rather than graves with stone arrangements, and LEH in plain graves rather than graves with a cover or marker, suggests that individuals buried in more elaborate graves enjoyed better levels of health and may been of higher social status than those buried in plain graves."

Variability of the Stature of the Central European Population from the Neolithic Age to Present
M. Dobisíková, S. Katina, P. Velemínský
The aim of our contribution is to characterize the changes of the stature in adult populations that have lived in Central Europe from the Neolithic period up to the present. Our sample consisted of 802 male and 704 female skeletons. The evaluation was conducted taking into account the demographic structure of the groups studied. We confronted the findings with the living
conditions of the populations known to have a significant impact on human stature, in
addition to genetic factors. We thus considered the socioeconomic status of the populations that might have influenced the quality of nutrition. We focused our attention on the socioeconomic aspect of populations of the early Middle Ages and the recent population. We compared socially higher placed part of the society with socially poorer classes (agricultural groups) (177 male, 178 female) in the early-medieval population of Great Moravia. No statistically significant
differences were found among individual social groups. To calculate the stature of last populations we used the regression equations developed by Breitiger (1937) and Bach (1965). The
calculation was based only on the length of the femur that is directly involved in body length. The impact of the secular trend was evaluated in the recent population. We compared two autopsy skeletal samples from the beginning and ends of the 20th century (107 male, 53 female). Statistically significant differences between them was found. Finally, we proposed regression equations for calculating the stature of the contemporary Czech population usable in forensic practice.

A phylogeographic analysis of haplogroup D5 and its implications for the peopling of East Asia.
M.C. Dulik
While genetic studies have focused on the Altai region of South Siberia as a possible place of origin for Native Americans, it is also possible that it played a similarly significant role in the peopling of East Asia. A Siberian connection to other East Asian populations has already been proposed based on archaeological, linguistic and classical genetic marker evidence. In this study, we examined a rare and ancient haplogroup, D5c, in an effort to elucidate early population movements in East Asia. Previous studies suggested that D5 first emerged in China and
spread northwards from there. However,given the number of D5c individuals (12) and the range of variation in D5 from the Altai region, it is conceivable that this haplogroup instead originated in South Siberia and spread from there during the initial movements of Paleolithic peoples. To est this hypothesis, we obtained complete mtDNA sequences for individuals represented by aplogroups D4 and D5 and acquired additional sequences available through GenBank and published literature. We then analyzed the entire dataset with the reduced median network approach and
phylogeographic modeling. Our results suggest that Southern Siberia did play a
critical role in the spread of the D5 haplogroup. This focus on relatively unique
mtDNA lineages specific to certain populations allowed us to better understand
the processes of ancient settlement and subsequent population movements that helped shape the current genetic landscape of East Asia.

More than meets the eye: LB1, the transforming hominin.
R.B. Eckhard et al.

LB1 is not a microcephalic.
D. Falk1 et al.

Is there biological meaning to “Hispanic” in New Mexico?
H.J.H. Edgar, C.M. Willermet

Establishing the nature of the differences between skull samples from two populations.
S.P. Evans et al.
A sample of 1188 skulls from the Romano-British site at Poundbury shows differences from the 18th century sample of 822 skulls from Spitalfields. Both sites are in the south of England, but 1400 years apart in time. The differences between the sites could be due to immigrations over time and/or to adaptation to the environment. The aim of the study was to establish the nature of the differences, in particular the relative importance of genetic and acquired traits.
Frequencies of 22 selected non-metric traits in juvenile, female and male skulls were analysed. Initial logistic regression analyses established that there was a substantial difference between the two sites and between juveniles and adults, with some sexual dimorphism. The modified mean
measure of divergence, used to calculate overall distances between the groups, showed the juvenile groups to be closer to each other than to adults from their respective sites. Across sites, males were most distant from each other. The largest distance was between Spitalfields juveniles and males. Principal coordinate analysis, followed by a jackknife stability analysis, revealed a pattern indicating that this came about through growth and adaptation. Omitting traits in turn, procrustes methods were used to identify the most influential, all of which
were acquired through ageing or lifestyle. Without these traits there was no significant
difference between the two juvenile groups and no sexual dimorphism. These results show the importance of the behavioural environment in determining morphology, and the resilience of populations to genetic change.

Peopling of the Pacific: resolving the controversy.
J.S. Friedlaender et al.
"Our survey of mitochondrial DNA, Ychromosome, and over 600 short tandem repeat polymorphisms and 200 insertiondeletions from over 40 Pacific populations indicates Polynesians have their genetic
origins to both Melanesian and Taiwanese (Southeast Asian) populations in significant degrees. In Island Melanesia, there is a small but clear ancient genetic footprint in certain Oceanic-speaking populations (i.e., linguistically related to Polynesian). The survey results underscore the extraordinary diversity of Island Melanesian populations from one language group to another, and from island to island. This is the result of the small sizes of the populations and the very long extent of modern human settlement there (over 30,000 years)."

Multivariate studies of cranial form: the impact of Howells' research on defining Homo sapiens.
J.B. Gaines et al.

Demographic simulations of the admixture between foragers and farmers in central European Neolithic.
P. Galeta, J. Bruzek.

William White Howells: A physical anthropologist in the making.
E. Giles

The relationship of Nubians with their neighbors, the Egyptians.
By, K. Godde.

The Phylogeography of Haplogroup N1a
Gokcumen O et al.
Recent studies have revealed a complex geographic distribution of haplogroup N1a. This rare and distinctive lineage is widely distributed across Eurasia and Africa, but always found at very low frequencies. However, despite its rarity, the genetic diversity within N1a has remained relatively high (h=0.9605). The reduced median network of N1a haplotypes not only reflects
this level of diversity, but also exhibits several relatively well-defined branches. The
distribution of N1a is intriguing because of revealing previously unrecognized connections between populations. What makes N1a even more interesting is the prevalence of this lineage in ancient European populations. Haak et al. (2005) found that 25% of their European Neolithic
samples belonged to N1a and dated to ~5000 BCE, whereas the frequency of this lineage in contemporary Europeans is only ~0.2%. In addition, an Iron Age skeleton from Kazakhstan had an N1a haplotype, suggesting the existence of this lineage in the Altai Republic in ~500BCE (Ricaut et al. 2004). Indeed, we found several haplogroup N1a mtDNAs in indigenous Altaians and Altaian Kazakhs. To further elucidate the phylogeography of this lineage in Central Asia, we sequenced the whole mtDNA genomes of our N1a haplotypes, and analyzed the resulting data with several quantitative methods and simulation programs to estimate their expansion times and spatial
distribution in Eurasia. Our findings suggest that there are two well-defined sublineages
within N1a, and that the dispersal of this haplogroup could be associated with the Neolithic expansion and with prehistoric interactions between Central Asian and European populations.


Understanding human races: the retreat of neutralism.
Henry Harpending
Discussion and debate about human races has been dominated for decades by neutral theory and statistics. Since this literature never posed a real question, it has never produced an answer. Lewontin's 1972 paper with its claim that a value of 1/8 of a statistic like Fst is “small” and that this means that human race differences are insignificant is a staple of our textbooks. Recently geneticists have had a closer look and pointed out that Fst of 1/8 describes differences among sets of half sibs and few claim that half sibs are insignificantly related. Anthony Edwards has shown that the significance of differences is in the correlation structure of a large number of traits, again denying the Lewontin assertion that human differences are small. Alan Templeton in 1998 claimed that human races were less differentiated that races of some other large mammals, but he compared human nuclear DNA statistics with statistics from mtDNA in the other species. An appropriate comparison shows that human are more, not less, differentiated than other large mammal species. Since neutral differences are a passive
record of demographic history they are not very significant for issues of functional biology. Newly available data sources allow us to study the natural selection of race differences instead of their drift. It appears that there is a lot of ongoing evolution in our species and the loci under strong selection on different continents only partially overlap. Human race differences may be increasing rapidly.

Acceleration of adaptive evolution in modern humans.
J. Hawks and G. Cochran
Humans vastly increased in numbers during the past 40,000 years. Recent surveys of human genomic variation have suggested a large surplus of recent positive selection, indicated by excess linkage disequilibrium and skewed SNP frequency spectra. We applied estimates of prehistoric and historic population sizes to estimate the importance of population growth in explaining the number of recent adaptive mutations. Our estimates are consistent with genomic evidence in suggesting that the rate of generation of positively selected genes has increased as much as a hundredfold during the past 40,000 years.

Do skeletal features reflect this genomic evidence of selection? Under positive
selection, rapid appearance of new variants during the terminal Pleistocene and early
Holocene would cause maximal phenotypic change during the last 2000-4000 years. We compared original and published series of Holocene cranial data from Europe, Jordan, Nubia, South Africa, and China, in addition to Late Pleistocene samples from Europe and West Asia, to test the hypothesis that the genomic acceleration in positive selection correlates with phenotypic evolution during this time period. A constellation of features in the face and cranial vault, notably including endocranial volume, changed globally during this time period and documents common patterns of selection in different regions. Holocene changes were similar in pattern and chronologically faster than those at the archaic-modern transition, which themselves were rapid compared to earlier hominid evolution. In genomic and craniometric terms, the origin of modern humans was a minor event compared to more recent evolutionary changes.

Patterns of admixture in Mexican Americans assessed from 101,150 SNPs.
M.G. Hayes et al.
"No significant differences were observed between the 10 subsets, allowing us to average the admixture estimates across the subsets: 68% European, 27% Asian (as a proxy for Native American), and 6% African."

Gender, wealth, and status in Bronze Age Central Asia: a dental pathology investigation.
B.E. Hemphill.

Sahara passage: the post-glacial recolonisation of North Africa by mitochondrial L* haplotypes.
AD Holden. P Forster.

Secular trends of the European male facial skull from the Migration Period to the present.
E. Jonke et al.
We examined secular trends in the facial skull over three Central European samples spanning more than 13 centuries. Data are 43 conventional cephalometric landmark points for samples dating from 680–830 CE, from the mid-19th Century, and from living Austrian young adult males. Methods of geometric morphometrics demonstrate shape differences across the samples, and also
differences in allometry. There is a stronginteraction between these, so that group mean differences are different for small and large individuals (equivalently, allometry is
different from period to period). The oldest sample, from the Migration Period, exhibits
allometric features that may possibly be Turkic. There are implications for the
craniofacial biologist interested in growth trends or growth predictions in ethnically
mixed populations. There are also implications for the discussion concerning the morphology of the Avars (an ethnic group of probably Central Asian origin who conquered large parts of Central Europe during the Migration Period and who interbred with other incoming groups after their conquest by Charlemagne), and also the relation of these findings to current thinking on gnathic reduction trends.

Roman Gladiators - The Osseous Evidence.
F. Kanz, K. Grossschmidt

Paternal heritage for the Indonesian peoples.
T. M. Karafet et al.

Feeding the children: Isotopic evidence for weaning practices in the ancient Greek colony of Apollonia (5th-2nd centuries BC).
C. Kwok, A. Keenleyside.

Misconceptions about the postcranial skeleton of Homo floresiensis.
S.G. Larson et al.

A comparison of mitochondrial DNA and Y chromosome DNA variation on Manus Island.
K.E. Latham et al.