Antiquity Volume: 86 Number: 332 Page: 325–337
The earliest surviving textiles in East Asia from Chertovy Vorota Cave, Primorye Province, Russian Far East
Yaroslav V. Kuzmin et al.
Carbonised textiles were found in a burnt down building inside a cave 30km from the far eastern coast of Russia. The textiles were made from untwisted or hand-twisted blades of sedge grass to form ropes, nets and woven mats. Dated by AMS to c. 9400–8400 cal BP these are the earliest textiles so far known from East Asia.
Link
May 31, 2012
The smell of age
PLoS ONE 7(5): e38110. doi:10.1371/journal.pone.0038110
The Smell of Age: Perception and Discrimination of Body Odors of Different Ages
Susanna Mitro et al.
Our natural body odor goes through several stages of age-dependent changes in chemical composition as we grow older. Similar changes have been reported for several animal species and are thought to facilitate age discrimination of an individual based on body odors, alone. We sought to determine whether humans are able to discriminate between body odor of humans of different ages. Body odors were sampled from three distinct age groups: Young (20–30 years old), Middle-age (45–55), and Old-age (75–95) individuals. Perceptual ratings and age discrimination performance were assessed in 41 young participants. There were significant differences in ratings of both intensity and pleasantness, where body odors from the Old-age group were rated as less intense and less unpleasant than body odors originating from Young and Middle-age donors. Participants were able to discriminate between age categories, with body odor from Old-age donors mediating the effect also after removing variance explained by intensity differences. Similarly, participants were able to correctly assign age labels to body odors originating from Old-age donors but not to body odors originating from other age groups. This experiment suggests that, akin to other animals, humans are able to discriminate age based on body odor alone and that this effect is mediated mainly by body odors emitted by individuals of old age.
Link
The Smell of Age: Perception and Discrimination of Body Odors of Different Ages
Susanna Mitro et al.
Our natural body odor goes through several stages of age-dependent changes in chemical composition as we grow older. Similar changes have been reported for several animal species and are thought to facilitate age discrimination of an individual based on body odors, alone. We sought to determine whether humans are able to discriminate between body odor of humans of different ages. Body odors were sampled from three distinct age groups: Young (20–30 years old), Middle-age (45–55), and Old-age (75–95) individuals. Perceptual ratings and age discrimination performance were assessed in 41 young participants. There were significant differences in ratings of both intensity and pleasantness, where body odors from the Old-age group were rated as less intense and less unpleasant than body odors originating from Young and Middle-age donors. Participants were able to discriminate between age categories, with body odor from Old-age donors mediating the effect also after removing variance explained by intensity differences. Similarly, participants were able to correctly assign age labels to body odors originating from Old-age donors but not to body odors originating from other age groups. This experiment suggests that, akin to other animals, humans are able to discriminate age based on body odor alone and that this effect is mediated mainly by body odors emitted by individuals of old age.
Link
May 30, 2012
Spatial Ancestry Analysis (Yang et al. 2012)
Link to SPA software.
Nature Genetics 44, 725–731 (2012) doi:10.1038/ng.2285
A model-based approach for analysis of spatial structure in genetic data
Wen-Yun Yang et al.
Characterizing genetic diversity within and between populations has broad applications in studies of human disease and evolution. We propose a new approach, spatial ancestry analysis, for the modeling of genotypes in two- or three-dimensional space. In spatial ancestry analysis (SPA), we explicitly model the spatial distribution of each SNP by assigning an allele frequency as a continuous function in geographic space. We show that the explicit modeling of the allele frequency allows individuals to be localized on the map on the basis of their genetic information alone. We apply our SPA method to a European and a worldwide population genetic variation data set and identify SNPs showing large gradients in allele frequency, and we suggest these as candidate regions under selection. These regions include SNPs in the well-characterized LCT region, as well as at loci including FOXP2, OCA2 and LRP1B.
Link
Nature Genetics 44, 725–731 (2012) doi:10.1038/ng.2285
A model-based approach for analysis of spatial structure in genetic data
Wen-Yun Yang et al.
Characterizing genetic diversity within and between populations has broad applications in studies of human disease and evolution. We propose a new approach, spatial ancestry analysis, for the modeling of genotypes in two- or three-dimensional space. In spatial ancestry analysis (SPA), we explicitly model the spatial distribution of each SNP by assigning an allele frequency as a continuous function in geographic space. We show that the explicit modeling of the allele frequency allows individuals to be localized on the map on the basis of their genetic information alone. We apply our SPA method to a European and a worldwide population genetic variation data set and identify SNPs showing large gradients in allele frequency, and we suggest these as candidate regions under selection. These regions include SNPs in the well-characterized LCT region, as well as at loci including FOXP2, OCA2 and LRP1B.
Link
May 29, 2012
RIP matrilocal egalitarian early European farmers
It seems that Marija Gimbutas' feminist Old Europe fantasy is collapsing like a house of cards.
Michael Balter covers this in Science:
Michael Balter covers this in Science:
The results of the study, published online today in the Proceedings of the National Academy of Sciences, suggest that men who were buried with adzes—thought to be an indication of higher social status—were more likely to have grown up on loess soils than men who were buried without adzes.From the press release:
...
A similarly striking pattern was seen when the team looked at the female skeletons, which made up 153 of the total 311 individuals analyzed. The variation in strontium ratios for females was significantly greater than for males, suggesting that a greater number of females than males had grown up in non-fertile areas.
...
The team came to two main conclusions: First, some males had greater access to fertile soils than others, probably because they were the sons of farmers who had inherited access to the best land. And second, LBK societies were "patrilocal," meaning that males tended to stay put in one place while females moved in from other areas to mate with them.
Professor Bentley said: "Our results, along with archaeobotanical studies that indicate the earliest farmers of Neolithic Germany had a system of land tenure, suggest that the origins of differential access to land can be traced back to an early part of the Neolithic era, rather than only to later prehistory when inequality and intergenerational wealth transfers are more clearly evidenced in burials and material culture.
"It seems the Neolithic era introduced heritable property (land and livestock) into Europe and that wealth inequality got underway when this happened. After that, of course, there was no looking back: through the Bronze Age, Iron Age and Industrial era wealth inequality increased but the 'seeds' of inequality were sown way back in the Neolithic."PNAS doi: 10.1073/pnas.1113710109
Community differentiation and kinship among Europe’s first farmers
R. Alexander Bentley et al.
Community differentiation is a fundamental topic of the social sciences, and its prehistoric origins in Europe are typically assumed to lie among the complex, densely populated societies that developed millennia after their Neolithic predecessors. Here we present the earliest, statistically significant evidence for such differentiation among the first farmers of Neolithic Europe. By using strontium isotopic data from more than 300 early Neolithic human skeletons, we find significantly less variance in geographic signatures among males than we find among females, and less variance among burials with ground stone adzes than burials without such adzes. From this, in context with other available evidence, we infer differential land use in early Neolithic central Europe within a patrilocal kinship system.
Link
May 26, 2012
43,000-year old Aurignacian in Swabian Jura
A new paper continues the re-assessment of the radiocarbon dating record in Europe. It pushes the Aurignacian of Central Europe back in time, but not as far back as the appearance of modern humans in Europe. The implication is that the advanced music and art of the Aurignacian did not accompany modern humans as they made their first steps into Europe, but rather developed there.
The authors distinguish between a "strong" version of their model (which would posit a monocentric origin of music/art around the Geissenkoesterle site), and a "weak" one in which these innovations were contributed in parallel by different regions. A better understanding of the origin of different innovations and their assignment to specific groups of modern humans may help us better understand what was the "common core" of behavioral and technological modernity that facilitated the success of our species.
From the paper:
Τesting models for the beginnings of the Aurignacian and the advent of figurative art and music: The radiocarbon chronology of Geißenklösterle
Thomas Higham et al.
The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery.
Link
The authors distinguish between a "strong" version of their model (which would posit a monocentric origin of music/art around the Geissenkoesterle site), and a "weak" one in which these innovations were contributed in parallel by different regions. A better understanding of the origin of different innovations and their assignment to specific groups of modern humans may help us better understand what was the "common core" of behavioral and technological modernity that facilitated the success of our species.
From the paper:
The majority of scholars conclude that the Aurignacian is the earliest signature of the first modern humans in Europe. Recent research suggests that this is not likely to be the case. Benazzi et al. (2011) have shown that the Uluzzian of Italy and Greece is likely to be a modern human industry based on the reanalysis of infant teeth in the archaeological site of Cavallo, and also demonstrated that it dates to 45,000-43,000 cal BP. Other dated examples from other Uluzzian sites (e.g., Higham et al., 2009) fall into the same period, and the Uluzzian is always stratigraphically below the Proto- Aurignacian in Italian sites where both co-occur. This adds an additional level of complexity to the emerging picture of early human dispersals and suggests that the Aurignacian does not represent the earliest evidence of our species in Europe.
...
Taken together, these results suggest that modern humans arrived in Europe as early as ~45,000 cal BP and spread rapidly across Europe to as far as southern England between 43,000 and41,000 cal BP. The dates for the lower Aurignacian at Geissenklosterle fall in the same period and appear to pre-date the ages for the Proto- Aurignacian and Early Aurignacian in other regions (Fig. 6). The new results suggest that the caves of the Swabian Jura document the earliest phase of the Aurignacian, and the region can be viewed as one of the key areas in which a variety of cultural innovations, including figurative art, mythical images, and musical instruments, are first documented. These dates are consistent with the Danube Valley serving as an important corridor for the movement of people and ideas (Conard, 2002; Conard and Bolus, 2003).
...
The new radiocarbon dates from Geissenklosterle document the presence of the Aurignacian in the Swabian Jura prior to the Heinrich 4 cold phase, with the Early Aurignacian beginning around 42,500 cal BP. In the coming years, excavations in the Swabian Jura will continue and new radiometric dates should contribute to an improved understanding of the spatial-temporal development of the Aurignacian and its innovative material culture.From the press release:
Researchers from Oxford and Tübingen have published new radiocarbon dates from the from Geißenklösterle Cave in Swabian Jura of Southwestern Germany in the Journal of Human Evolution. The new dates use improved methods to remove contamination and produced ages between began between 42,000 – 43,000 years ago for start of the Aurignacian, the first culture to produce a wide range of figurative art, music and other key innovations as postulated in the Kulturpumpe Hypothesis. The full spectrum of these innovations were established in the region no later than 40 000 years ago.Journal of Human Evolution doi:10.1016/j.jhevol.2012.03.003
Τesting models for the beginnings of the Aurignacian and the advent of figurative art and music: The radiocarbon chronology of Geißenklösterle
Thomas Higham et al.
The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery.
Link
May 24, 2012
May 23, 2012
Y-STR haplotype shared between Roma and South Indians
Gene. 2012 May 17. [Epub ahead of print]
Ancestral modal Y-STR haplotype shared among Romani and South Indian populations.
Regueiro M, Rivera L, Chennakrishnaiah S, Popovic B, Andjus S, Milasin J, Herrera RJ.
Abstract
One of the primary unanswered questions regarding the dispersal of Romani populations concerns the geographical region and/or the Indian caste/tribe that gave rise to the proto-Romani group. To shed light on this matter, 161 Y-chromosomes from Roma, residing in two different provinces of Serbian, were analyzed. Our results indicate that the paternal gene pool of both groups is shaped by several strata, the most prominent of which, H1-M52, comprises almost half of each collection's patrilineages. The high frequency of M52 chromosomes in the two Roma populations examined may suggest that they descend from a single founder that has its origins in the Indian subcontinent. Moreover, when the Y-STR profiles of haplogroup H derived individuals in our Roma populations were compared to those typed in the South Indian emigrants from Malaysia and groups from Madras, Karnataka (Lingayat and Vokkaliga castes) and tribal Soligas, sharing of the two most common haplotypes was observed. These similarities suggest that South India may have been one of the contributors to the proto-Romanis. European genetic signatures (i.e., haplogroups E1b1b1a1b -V13, G2a-P15, I-M258, J2-M172 and R1-M173), on the other hand, were also detected in both groups, but at varying frequencies. The divergent European genetic signals in each collection are likely the result of differential gene flow and/or admixture with the European host populations but may also be attributed to dissimilar endogamous practices following the initial founder effect. Our data also supports the notion that a number of haplogroups including G2a-P15, J2a3b-M67(xM92), I-M258 and E1b1b1-M35 were incorporated into the proto-Romani paternal lineages as migrants moved from northern India through Southwestern Asia, the Middle East and/or Anatolia into the Balkans.
Link
Ancestral modal Y-STR haplotype shared among Romani and South Indian populations.
Regueiro M, Rivera L, Chennakrishnaiah S, Popovic B, Andjus S, Milasin J, Herrera RJ.
Abstract
One of the primary unanswered questions regarding the dispersal of Romani populations concerns the geographical region and/or the Indian caste/tribe that gave rise to the proto-Romani group. To shed light on this matter, 161 Y-chromosomes from Roma, residing in two different provinces of Serbian, were analyzed. Our results indicate that the paternal gene pool of both groups is shaped by several strata, the most prominent of which, H1-M52, comprises almost half of each collection's patrilineages. The high frequency of M52 chromosomes in the two Roma populations examined may suggest that they descend from a single founder that has its origins in the Indian subcontinent. Moreover, when the Y-STR profiles of haplogroup H derived individuals in our Roma populations were compared to those typed in the South Indian emigrants from Malaysia and groups from Madras, Karnataka (Lingayat and Vokkaliga castes) and tribal Soligas, sharing of the two most common haplotypes was observed. These similarities suggest that South India may have been one of the contributors to the proto-Romanis. European genetic signatures (i.e., haplogroups E1b1b1a1b -V13, G2a-P15, I-M258, J2-M172 and R1-M173), on the other hand, were also detected in both groups, but at varying frequencies. The divergent European genetic signals in each collection are likely the result of differential gene flow and/or admixture with the European host populations but may also be attributed to dissimilar endogamous practices following the initial founder effect. Our data also supports the notion that a number of haplogroups including G2a-P15, J2a3b-M67(xM92), I-M258 and E1b1b1-M35 were incorporated into the proto-Romani paternal lineages as migrants moved from northern India through Southwestern Asia, the Middle East and/or Anatolia into the Balkans.
Link
May 20, 2012
Ancestry, admixture and selection in Bolivian and Totonac populations
BMC Genetics 2012, 13:39 doi:10.1186/1471-2156-13-39
Genetic analysis of ancestry, admixture and selection in Bolivian and Totonac populations of the New World
W Scott Watkins, Jinchuan Xing, Chad Huff, David J Witherspoon, Yuhua Zhang, Ugo A Perego, Scott R Woodward and Lynn B Jorde
Abstract (provisional)
Background
Populations of the Americas were founded by early migrants from Asia, and some have experienced recent genetic admixture. To better characterize the native and non-native ancestry components in populations from the Americas, we analyzed 815,377 autosomal SNPs, mitochondrial hypervariable segments I and II, and 36 Y-chromosome STRs from 24 Mesoamerican Totonacs and 23 South American Bolivians.
Results and conclusions
We analyzed common genomic regions from native Bolivian and Totonac populations to identify 324 highly predictive Native American ancestry informative markers (AIMs). As few as 40-50 of these AIMs perform nearly as well as large panels of random genome-wide SNPs for predicting and estimating Native American ancestry and admixture levels. These AIMs have greater New World vs. Old World specificity than previous AIMs sets. We identify highly-divergent New World SNPs that coincide with high-frequency haplotypes found at similar frequencies in all populations examined, including the HGDP Pima, Maya, Colombian, Karitiana, and Surui American populations. Some of these regions are potential candidates for positive selection. European admixture in the Bolivian sample is approximately 12%, though individual estimates range from 0-48%. We estimate that the admixture occurred ~360-384 years ago. Little evidence of European or African admixture was found in Totonac individuals. Bolivians with pre-Columbian mtDNA and Ychromosome haplogroups had 5-30% autosomal European ancestry, demonstrating the limitations of Y-chromosome and mtDNA haplogroups and the need for autosomal ancestry informative markers for assessing ancestry in admixed populations.
Link
Genetic analysis of ancestry, admixture and selection in Bolivian and Totonac populations of the New World
W Scott Watkins, Jinchuan Xing, Chad Huff, David J Witherspoon, Yuhua Zhang, Ugo A Perego, Scott R Woodward and Lynn B Jorde
Abstract (provisional)
Background
Populations of the Americas were founded by early migrants from Asia, and some have experienced recent genetic admixture. To better characterize the native and non-native ancestry components in populations from the Americas, we analyzed 815,377 autosomal SNPs, mitochondrial hypervariable segments I and II, and 36 Y-chromosome STRs from 24 Mesoamerican Totonacs and 23 South American Bolivians.
Results and conclusions
We analyzed common genomic regions from native Bolivian and Totonac populations to identify 324 highly predictive Native American ancestry informative markers (AIMs). As few as 40-50 of these AIMs perform nearly as well as large panels of random genome-wide SNPs for predicting and estimating Native American ancestry and admixture levels. These AIMs have greater New World vs. Old World specificity than previous AIMs sets. We identify highly-divergent New World SNPs that coincide with high-frequency haplotypes found at similar frequencies in all populations examined, including the HGDP Pima, Maya, Colombian, Karitiana, and Surui American populations. Some of these regions are potential candidates for positive selection. European admixture in the Bolivian sample is approximately 12%, though individual estimates range from 0-48%. We estimate that the admixture occurred ~360-384 years ago. Little evidence of European or African admixture was found in Totonac individuals. Bolivians with pre-Columbian mtDNA and Ychromosome haplogroups had 5-30% autosomal European ancestry, demonstrating the limitations of Y-chromosome and mtDNA haplogroups and the need for autosomal ancestry informative markers for assessing ancestry in admixed populations.
Link
May 19, 2012
African genetics international conference (video)
A bunch of talks from the African Genetics International Conference have been posted.
You can refer to this list of talks.
I haven't watched any of the videos yet; feel free to comment on any interesting nuggets of information in them.
A few that I plan to watch:
(UPDATE: A very interesting bit at around 42')
Beyond Eden: The Significance of Archaic Human Genetic Sequences in African Populations
Michael Hammer, University of Arizona
The following video has been pixelized, presumably because it includes pictures of unpublished data (?)
Paleoanthropological Origins of Human Genetic Diversity: The Significance of humanity’s African Roots
Chris Stringer, Natural History Museum, London
Technological Innovations Impacting Genomic Science
George Church, Harvard & MIT
You can refer to this list of talks.
I haven't watched any of the videos yet; feel free to comment on any interesting nuggets of information in them.
A few that I plan to watch:
(UPDATE: A very interesting bit at around 42')
Beyond Eden: The Significance of Archaic Human Genetic Sequences in African Populations
Michael Hammer, University of Arizona
The following video has been pixelized, presumably because it includes pictures of unpublished data (?)
Paleoanthropological Origins of Human Genetic Diversity: The Significance of humanity’s African Roots
Chris Stringer, Natural History Museum, London
Technological Innovations Impacting Genomic Science
George Church, Harvard & MIT
May 17, 2012
Science special issue on Human Conflict
The content is free for registered users (not necessarily subscribers).
May 16, 2012
Major new paper on Y chromosome haplogroup G (Rootsi et al. 2012)
Haplogroup G is of substantial interest to prehistorians, because it has been sampled on multiple Neolithic locations from across Europe. A new paper updates the phylogeny of this important haplogroup (left), and studies its distribution. You can find information about the frequency of different haplogroup G subclades in the freely available supplementary material (Table 1).
From the paper:
A couple of lineages of interest are M527 which is a low-frequency haplogroup which the authors associate with Greek colonization and the Sea Peoples, and L497 which they associate with the LBK. It would certainly be interesting to test for the latter in some of the existing ancient DNA samples.
Finally, the following is of interest:
Rather, it begins to appear that there once was a (roughly speaking) western-eastern-southern distribution of the G/R1/J2 lineages in the territory of West Asia; this would be compatible with both the Neolithic European G dominance, the paucity of G in Central/South Asia, and its NW/S vs. NE Caucasus differentiation.
European Journal of Human Genetics advance online publication 16 May 2012; doi: 10.1038/ejhg.2012.86
Distinguishing the co-ancestries of haplogroup G Y-chromosomes in the populations of Europe and the Caucasus
Siiri Rootsi et al.
Haplogroup G, together with J2 clades, has been associated with the spread of agriculture, especially in the European context. However, interpretations based on simple haplogroup frequency clines do not recognize underlying patterns of genetic diversification. Although progress has been recently made in resolving the haplogroup G phylogeny, a comprehensive survey of the geographic distribution patterns of the significant sub-clades of this haplogroup has not been conducted yet. Here we present the haplogroup frequency distribution and STR variation of 16 informative G sub-clades by evaluating 1472 haplogroup G chromosomes belonging to 98 populations ranging from Europe to Pakistan. Although no basal G-M201* chromosomes were detected in our data set, the homeland of this haplogroup has been estimated to be somewhere nearby eastern Anatolia, Armenia or western Iran, the only areas characterized by the co-presence of deep basal branches as well as the occurrence of high sub-haplogroup diversity. The P303 SNP defines the most frequent and widespread G sub-haplogroup. However, its sub-clades have more localized distribution with the U1-defined branch largely restricted to Near/Middle Eastern and the Caucasus, whereas L497 lineages essentially occur in Europe where they likely originated. In contrast, the only U1 representative in Europe is the G-M527 lineage whose distribution pattern is consistent with regions of Greek colonization. No clinal patterns were detected suggesting that the distributions are rather indicative of isolation by distance and demographic complexities.
Link
From the paper:
First, we calculated haplogroup diversity using data in Supplementary Table S1 for the 52 instances when total population sample size exceeded 50 individuals and Z5 hg G chromosomes were observed. Then we applied a 10% overall hg G frequency threshold and the additional specification that both haplogroup G1 and G2 lineages also be present. In the ten remaining populations, haplogroup diversity spanned from a low of 0.21 in Adyghes, to highs of 0.88 in Azeris (Iran) and 0.89 in eastern Anatolia and 0.90 in Armenia. We estimate that the geographic origin of hg G plausibly locates somewhere nearby eastern Anatolia, Armenia or western Iran. The general frequency pattern of hg G overall (Figure 2a) shows that the spread of hg G extends over an area from southern Europe to the Near/Middle East and the Caucasus, but then decreases rapidly toward southern and Central Asia.It is certainly interesting that the estimated region of origin of haplogroup G intersects my so-called "womb of nations", out of which I believe flowed populations after the inception of the Neolithic. The rapid diminution of this haplogroup in Central/South Asia may be compatible with the relative lack of the K=7 "Southern" autosomal component in populations of the area, in contrast to a couple of Neolithic European farmers (the Tyrolean Iceman and Gok4). The Iceman himself belonged to haplogroup G, and so did individuals from Derenburg LBK, and Treilles.
A couple of lineages of interest are M527 which is a low-frequency haplogroup which the authors associate with Greek colonization and the Sea Peoples, and L497 which they associate with the LBK. It would certainly be interesting to test for the latter in some of the existing ancient DNA samples.
Finally, the following is of interest:
Concerning the presence of hg G in the Caucasus, one of its distinguishing features is lower haplogroup diversity in numerous populations (Supplementary Table S1) compared with Anatolia and Armenia, implying that hg G is intrusive in the Caucasus rather than autochthonous. Another notable feature is its uneven distribution. Hg G is very frequent in NW Caucasus and South Caucasus, covering about 45% of the paternal lineages in both regions2 in this study. Conversely, hg G is present in Northeast Caucasus only at an average frequency of 5% (range 0–19%). Interestingly, the decrease of hg G frequency towards the eastern European populations inhabiting the area adjacent to NW Caucasus, such as southern Russians and Ukrainians,18,40 is very rapid and the borderline very sharp, indicating that gene flow from the Caucasus in the northern direction has been negligible.Unfortunately, we currently lack ancient Y-DNA samples from West Asia. But, certainly, the samples we do have from Europe are indicative of shifts in West Asia as well, since the predominance of Y-haplogroup G in Neolithic Europe is hardly compatible with a haplogroup composition in the eastern source areas similar to today's.
Rather, it begins to appear that there once was a (roughly speaking) western-eastern-southern distribution of the G/R1/J2 lineages in the territory of West Asia; this would be compatible with both the Neolithic European G dominance, the paucity of G in Central/South Asia, and its NW/S vs. NE Caucasus differentiation.
European Journal of Human Genetics advance online publication 16 May 2012; doi: 10.1038/ejhg.2012.86
Distinguishing the co-ancestries of haplogroup G Y-chromosomes in the populations of Europe and the Caucasus
Siiri Rootsi et al.
Haplogroup G, together with J2 clades, has been associated with the spread of agriculture, especially in the European context. However, interpretations based on simple haplogroup frequency clines do not recognize underlying patterns of genetic diversification. Although progress has been recently made in resolving the haplogroup G phylogeny, a comprehensive survey of the geographic distribution patterns of the significant sub-clades of this haplogroup has not been conducted yet. Here we present the haplogroup frequency distribution and STR variation of 16 informative G sub-clades by evaluating 1472 haplogroup G chromosomes belonging to 98 populations ranging from Europe to Pakistan. Although no basal G-M201* chromosomes were detected in our data set, the homeland of this haplogroup has been estimated to be somewhere nearby eastern Anatolia, Armenia or western Iran, the only areas characterized by the co-presence of deep basal branches as well as the occurrence of high sub-haplogroup diversity. The P303 SNP defines the most frequent and widespread G sub-haplogroup. However, its sub-clades have more localized distribution with the U1-defined branch largely restricted to Near/Middle Eastern and the Caucasus, whereas L497 lineages essentially occur in Europe where they likely originated. In contrast, the only U1 representative in Europe is the G-M527 lineage whose distribution pattern is consistent with regions of Greek colonization. No clinal patterns were detected suggesting that the distributions are rather indicative of isolation by distance and demographic complexities.
Link
May 15, 2012
ORBIS: The Stanford Geospatial Network Model of the Roman World
A very useful new tool.
Screenshot:
Example output:
The fastest journey from Roma to Constantinopolis in January takes 20.7 days, covering 2951 kilometers.
Prices in denarii, based on the use of a faster sail ship and a civilian river boat (where applicable), and on these road options:
* Per kilogram of wheat (by donkey): 4.37
* Per kilogram of wheat (by wagon): 4.99
* Per passenger in a carriage: 580.42
Screenshot:
Example output:
The fastest journey from Roma to Constantinopolis in January takes 20.7 days, covering 2951 kilometers.
Prices in denarii, based on the use of a faster sail ship and a civilian river boat (where applicable), and on these road options:
* Per kilogram of wheat (by donkey): 4.37
* Per kilogram of wheat (by wagon): 4.99
* Per passenger in a carriage: 580.42
May 14, 2012
Y chromosome diversity in Native Mexicans (Sandoval et al. 2012)
From the paper:
Y-chromosome diversity in Native Mexicans reveals continental transition of genetic structure in the Americas
Karla Sandoval et al.
The genetic characterization of Native Mexicans is important to understand multiethnic based features influencing the medical genetics of present Mexican populations, as well as to the reconstruct the peopling of the Americas. We describe the Y-chromosome genetic diversity of 197 Native Mexicans from 11 populations and 1,044 individuals from 44 Native American populations after combining with publicly available data. We found extensive heterogeneity among Native Mexican populations and ample segregation of Q-M242* (46%) and Q-M3 (54%) haplogroups within Mexico. The northernmost sampled populations falling outside Mesoamerica (Pima and Tarahumara) showed a clear differentiation with respect to the other populations, which is in agreement with previous results from mtDNA lineages. However, our results point toward a complex genetic makeup of Native Mexicans whose maternal and paternal lineages reveal different narratives of their population history, with sex-biased continental contributions and different admixture proportions. At a continental scale, we found that Arctic populations and the northernmost groups from North America cluster together, but we did not find a clear differentiation within Mesoamerica and the rest of the continent, which coupled with the fact that the majority of individuals from Central and South American samples are restricted to the Q-M3 branch, supports the notion that most Native Americans from Mesoamerica southwards are descendants from a single wave of migration. This observation is compatible with the idea that present day Mexico might have constituted an area of transition in the diversification of paternal lineages during the colonization of the Americas.
Link
The first dimension of the CoA (60.53%) separates Q-M3 from the rest, and the second dimension (39.47%) C-M130 from the rest. In agreement ith the known distribution of haplogroup C, we observed that the two northernmost populations of this panel (Chippewa and Sioux) cluster next to C-M130 and the rest of populations show varying proportions of Q-M242 and Q-M3. It is noteworthy that Native Mexicans are the only regional group with populations represented next to both the Q-M242 cluster and the Q-M3 cluster. In contrast, all Central and South American samples were grouped significantly closer to the Q-M3 haplogroup (Fig. 3).Am J Phys Anthropol DOI: 10.1002/ajpa.22062
Y-chromosome diversity in Native Mexicans reveals continental transition of genetic structure in the Americas
Karla Sandoval et al.
The genetic characterization of Native Mexicans is important to understand multiethnic based features influencing the medical genetics of present Mexican populations, as well as to the reconstruct the peopling of the Americas. We describe the Y-chromosome genetic diversity of 197 Native Mexicans from 11 populations and 1,044 individuals from 44 Native American populations after combining with publicly available data. We found extensive heterogeneity among Native Mexican populations and ample segregation of Q-M242* (46%) and Q-M3 (54%) haplogroups within Mexico. The northernmost sampled populations falling outside Mesoamerica (Pima and Tarahumara) showed a clear differentiation with respect to the other populations, which is in agreement with previous results from mtDNA lineages. However, our results point toward a complex genetic makeup of Native Mexicans whose maternal and paternal lineages reveal different narratives of their population history, with sex-biased continental contributions and different admixture proportions. At a continental scale, we found that Arctic populations and the northernmost groups from North America cluster together, but we did not find a clear differentiation within Mesoamerica and the rest of the continent, which coupled with the fact that the majority of individuals from Central and South American samples are restricted to the Q-M3 branch, supports the notion that most Native Americans from Mesoamerica southwards are descendants from a single wave of migration. This observation is compatible with the idea that present day Mexico might have constituted an area of transition in the diversification of paternal lineages during the colonization of the Americas.
Link
May 13, 2012
Y chromosomes in Haiti and Jamaica (Simms et al. 2012)
The paper investigates the different signals of patrilineal ancestry in two Caribbean islands, finding the expect signals of European and African ancestry, as well as minor other signals from the New World, East Asia, and even South Asia.
I will just point out the presence of a DE* chromosome in Jamaica. Such chromosomes have occasionally turned up in both Asia and Africa, and they ought to be an object of further study, preferrably with full Y-chromosome sequencing technology, since a better resolution of the DE-YAP haplogroup's structure will go a long way towards solving many puzzles about prehistory.
Am J Phys Anthropol. 2012 May 11. doi: 10.1002/ajpa.22090.
Y-chromosomal diversity in Haiti and Jamaica: Contrasting levels of sex-biased gene flow.
Simms TM, Wright MR, Hernandez M, Perez OA, Ramirez EC, Martinez E, Herrera RJ.
Abstract
Although previous studies have characterized the genetic structure of populations from Haiti and Jamaica using classical and autosomal STR polymorphisms, the patrilineal influences that are present in these countries have yet to be explored. To address this lacuna, the current study aims to investigate, for the first time, the potential impact of different ancestral sources, unique colonial histories, and distinct family structures on the paternal profile of both groups. According to previous reports examining populations from the Americas, island-specific demographic histories can greatly impact population structure, including various patterns of sex-biased gene flow. Also, given the contrasting autosomal profiles provided in our earlier study (Simms et al.: Am J Phys Anthropol 142 (2010) 49-66), we hypothesize that the degree and directionality of gene flow from Europeans, Africans, Amerindians, and East Asians are dissimilar in the two countries. To test this premise, 177 high-resolution Y-chromosome binary markers and 17 Y-STR loci were typed in Haiti (n = 123) and Jamaica (n = 159) and subsequently utilized for phylogenetic comparisons to available reference collections encompassing Africa, Europe, Asia (East and South), and the New World. Our results reveal that both studied populations exhibit a predominantly South-Saharan paternal component, with haplogroups A1b-V152, A3-M32, B2-M182, E1a-M33, E1b1a-M2, E2b-M98, and R1b2-V88 comprising 77.2% and 66.7% of the Haitian and Jamaican paternal gene pools, respectively. Yet, European derived chromosomes (i.e., haplogroups G2a*-P15, I-M258, R1b1b-M269, and T-M184) were detected at commensurate levels in Haiti (20.3%) and Jamaica (18.9%), whereas Y-haplogroups indicative of Chinese [O-M175 (3.8%)] and Indian [H-M69 (0.6%) and L-M20 (0.6%)] ancestry were restricted to Jamaica.
Link
I will just point out the presence of a DE* chromosome in Jamaica. Such chromosomes have occasionally turned up in both Asia and Africa, and they ought to be an object of further study, preferrably with full Y-chromosome sequencing technology, since a better resolution of the DE-YAP haplogroup's structure will go a long way towards solving many puzzles about prehistory.
Am J Phys Anthropol. 2012 May 11. doi: 10.1002/ajpa.22090.
Y-chromosomal diversity in Haiti and Jamaica: Contrasting levels of sex-biased gene flow.
Simms TM, Wright MR, Hernandez M, Perez OA, Ramirez EC, Martinez E, Herrera RJ.
Abstract
Although previous studies have characterized the genetic structure of populations from Haiti and Jamaica using classical and autosomal STR polymorphisms, the patrilineal influences that are present in these countries have yet to be explored. To address this lacuna, the current study aims to investigate, for the first time, the potential impact of different ancestral sources, unique colonial histories, and distinct family structures on the paternal profile of both groups. According to previous reports examining populations from the Americas, island-specific demographic histories can greatly impact population structure, including various patterns of sex-biased gene flow. Also, given the contrasting autosomal profiles provided in our earlier study (Simms et al.: Am J Phys Anthropol 142 (2010) 49-66), we hypothesize that the degree and directionality of gene flow from Europeans, Africans, Amerindians, and East Asians are dissimilar in the two countries. To test this premise, 177 high-resolution Y-chromosome binary markers and 17 Y-STR loci were typed in Haiti (n = 123) and Jamaica (n = 159) and subsequently utilized for phylogenetic comparisons to available reference collections encompassing Africa, Europe, Asia (East and South), and the New World. Our results reveal that both studied populations exhibit a predominantly South-Saharan paternal component, with haplogroups A1b-V152, A3-M32, B2-M182, E1a-M33, E1b1a-M2, E2b-M98, and R1b2-V88 comprising 77.2% and 66.7% of the Haitian and Jamaican paternal gene pools, respectively. Yet, European derived chromosomes (i.e., haplogroups G2a*-P15, I-M258, R1b1b-M269, and T-M184) were detected at commensurate levels in Haiti (20.3%) and Jamaica (18.9%), whereas Y-haplogroups indicative of Chinese [O-M175 (3.8%)] and Indian [H-M69 (0.6%) and L-M20 (0.6%)] ancestry were restricted to Jamaica.
Link
May 12, 2012
4,000 year old rock art from Mongolia
4000-year-old rock art discovered in Mongolia
Eighteen rock art sites dating back over 4,000 years have been discovered by archaeologists in northern China's Inner Mongolia autonomous region. The prehistoric art was discovered in the Yinshan Mountains in Urad Middle Banner (an administration division of the Inner Mongolia Autonomous Region), said Liu Binjie, head of the Cultural Relics Bureau of Urad Middle Banner.Can a Chinese reader dig up some pictures of these faces? I've seen a few stories about these discoveries in various outlets, but only a very small picture as of yet. This has some information on the Rock Painting of Yinshan Mountains. Also: The Rock Art of Inner Mongolia & Ningxia (China).
...
Liu said that carvings of faces found on Yinshan Mountains cliffs are similar to those in the Helan Mountains, located on the boundary between Ningxia and Inner Mongolia. They are also similar to those in eastern Russia, showing close connections with ancient peoples' migration patterns, showing similar worship ceremonies.
May 10, 2012
Unknown language discovered in tablet from the Governor’s Palace in Tušhan
The Independent covers this:
Journal of Near Eastern Studies
Evidence for a Peripheral Language in a Neo-Assyrian Tablet from the Governor’s Palace in Tušhan (pp. 13-20) John MacGinnis DOI: 10.1086/664450 Stable URL: http://www.jstor.org/stable/10.1086/664450
Archaeologists have discovered evidence for a previously unknown ancient language – buried in the ruins of a 2800 year old Middle Eastern palace.
The discovery is important because it may help reveal the ethnic and cultural origins of some of history’s first ‘barbarians’ – mountain tribes which had, in previous millennia, preyed on the world’s first great civilizations, the cultures of early Mesopotamia in what is now Iraq.
Evidence of the long-lost language - probably spoken by a hitherto unknown people from the Zagros Mountains of western Iran – was found by a Cambridge University archaeologist as he deciphered an ancient clay writing tablet unearthed by an international archaeological team excavating an Assyrian imperial governors’ palace in the ancient city of Tushan, south-east Turkey.
The tablet revealed the names of 60 women – probably prisoners-of-war or victims of an Assyrian forced population transfer program. But when the Cambridge archaeologist – Dr. John MacGinnis - began to examine the names in detail, he realized that 45 of them bore no resemblance to any of the thousands of ancient Middle Eastern names already known to scholars.
...
Typical names, born by the women – the evidence for the lost language – include Ushimanay, Alagahnia, Irsakinna and Bisoonoomay.
Journal of Near Eastern Studies
Evidence for a Peripheral Language in a Neo-Assyrian Tablet from the Governor’s Palace in Tušhan (pp. 13-20) John MacGinnis DOI: 10.1086/664450 Stable URL: http://www.jstor.org/stable/10.1086/664450
May 09, 2012
Agriculture arrived in Cyprus 10,600 years ago
PNAS doi: 10.1073/pnas.1201693109
First wave of cultivators spread to Cyprus at least 10,600 y ago
Jean-Denis Vigne et al.
Early Neolithic sedentary villagers started cultivating wild cereals in the Near East 11,500 y ago [Pre-Pottery Neolithic A (PPNA)]. Recent discoveries indicated that Cyprus was frequented by Late PPNA people, but the earliest evidence until now for both the use of cereals and Neolithic villages on the island dates to 10,400 y ago. Here we present the recent archaeological excavation at Klimonas, which demonstrates that established villagers were living on Cyprus between 11,100 and 10,600 y ago. Villagers had stone artifacts and buildings (including a remarkable 10-m diameter communal building) that were similar to those found on Late PPNA sites on the mainland. Cereals were introduced from the Levant, and meat was obtained by hunting the only ungulate living on the island, a small indigenous Cypriot wild boar. Cats and small domestic dogs were brought from the mainland. This colonization suggests well-developed maritime capabilities by the PPNA period, but also that migration from the mainland may have occurred shortly after the beginning of agriculture.
Link
First wave of cultivators spread to Cyprus at least 10,600 y ago
Jean-Denis Vigne et al.
Early Neolithic sedentary villagers started cultivating wild cereals in the Near East 11,500 y ago [Pre-Pottery Neolithic A (PPNA)]. Recent discoveries indicated that Cyprus was frequented by Late PPNA people, but the earliest evidence until now for both the use of cereals and Neolithic villages on the island dates to 10,400 y ago. Here we present the recent archaeological excavation at Klimonas, which demonstrates that established villagers were living on Cyprus between 11,100 and 10,600 y ago. Villagers had stone artifacts and buildings (including a remarkable 10-m diameter communal building) that were similar to those found on Late PPNA sites on the mainland. Cereals were introduced from the Levant, and meat was obtained by hunting the only ungulate living on the island, a small indigenous Cypriot wild boar. Cats and small domestic dogs were brought from the mainland. This colonization suggests well-developed maritime capabilities by the PPNA period, but also that migration from the mainland may have occurred shortly after the beginning of agriculture.
Link
May 08, 2012
Patrilineal signals of Austronesian expansion in mainland Southeast Asia
There was a recent paper on the spread of Austronesian in Island Southeast Asia, and now here's one on its spread in mainland Southeast Asia. Information about sampled populations can be found in Table 1. Haplogroup frequencies below:
PLoS ONE 7(5): e36437. doi:10.1371/journal.pone.0036437
Patrilineal Perspective on the Austronesian Diffusion in Mainland Southeast Asia
Jun-Dong He et al.
The Cham people are the major Austronesian speakers of Mainland Southeast Asia (MSEA) and the reconstruction of the Cham population history can provide insights into their diffusion. In this study, we analyzed non-recombining region of the Y chromosome markers of 177 unrelated males from four populations in MSEA, including 59 Cham, 76 Kinh, 25 Lao, and 17 Thai individuals. Incorporating published data from mitochondrial DNA (mtDNA), our results indicated that, in general, the Chams are an indigenous Southeast Asian population. The origin of the Cham people involves the genetic admixture of the Austronesian immigrants from Island Southeast Asia (ISEA) with the local populations in MSEA. Discordance between the overall patterns of Y chromosome and mtDNA in the Chams is evidenced by the presence of some Y chromosome lineages that prevail in South Asians. Our results suggest that male-mediated dispersals via the spread of religions and business trade might play an important role in shaping the patrilineal gene pool of the Cham people.
Link
PLoS ONE 7(5): e36437. doi:10.1371/journal.pone.0036437
Patrilineal Perspective on the Austronesian Diffusion in Mainland Southeast Asia
Jun-Dong He et al.
The Cham people are the major Austronesian speakers of Mainland Southeast Asia (MSEA) and the reconstruction of the Cham population history can provide insights into their diffusion. In this study, we analyzed non-recombining region of the Y chromosome markers of 177 unrelated males from four populations in MSEA, including 59 Cham, 76 Kinh, 25 Lao, and 17 Thai individuals. Incorporating published data from mitochondrial DNA (mtDNA), our results indicated that, in general, the Chams are an indigenous Southeast Asian population. The origin of the Cham people involves the genetic admixture of the Austronesian immigrants from Island Southeast Asia (ISEA) with the local populations in MSEA. Discordance between the overall patterns of Y chromosome and mtDNA in the Chams is evidenced by the presence of some Y chromosome lineages that prevail in South Asians. Our results suggest that male-mediated dispersals via the spread of religions and business trade might play an important role in shaping the patrilineal gene pool of the Cham people.
Link
Late glacial recolonization of Europe from Near Eastern refugia
A couple of quick comments on this important new paper:
The American Journal of Human Genetics, Volume 90, Issue 5, 915-924, 4 May 2012 doi:10.1016/j.ajhg.2012.04.003
Mitochondrial DNA Signals of Late Glacial Recolonization of Europe from Near Eastern Refugia
Maria Pala et al.
Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ∼19–12 thousand years (ka) ago.
Link
- It is important to confirm the hypotheses put forward with ancient DNA data. For example, haplogroup V is said to be traced to Paleolithic SW Europe, and yet it is lacking in ancient DNA data. Looking at Jean Manco's ancient Eurasian DNA compendium, I only find a very late Neolithic hunter-gatherer sample from Pitted Ware in Sweden (2,800-2,000BC); if J/T subclades had entered Europe prior to the Neolithic, their almost complete absence in ancient DNA data is puzzling.
- Both this and the recent "Copernican" paper provide age estimates for the same nodes of the tree using the mutation rate of Soares et al. (2009). The estimaets of Pala et al. (2012) appear to be older by several thousand years than those of Behar et al. (2012) for different nodes. I don't know whether this is due to a different methodology or different dataset, but, in any case, it is a warning to avoid very close correlations between archaeological-geological events and age estimates.
The American Journal of Human Genetics, Volume 90, Issue 5, 915-924, 4 May 2012 doi:10.1016/j.ajhg.2012.04.003
Mitochondrial DNA Signals of Late Glacial Recolonization of Europe from Near Eastern Refugia
Maria Pala et al.
Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ∼19–12 thousand years (ka) ago.
Link
Genetic structure of North-East Sardinia (Pardo et al. 2012)
European Journal of Human Genetics , (29 February 2012) | doi:10.1038/ejhg.2012.22
Dissecting the genetic make-up of North-East Sardinia using a large set of haploid and autosomal markers
Luba M Pardo et al.
Abstract
Sardinia has been used for genetic studies because of its historical isolation, genetic homogeneity and increased prevalence of certain rare diseases. Controversy remains concerning the genetic substructure and the extent of genetic homogeneity, which has implications for the design of genome-wide association studies (GWAS). We revisited this issue by examining the genetic make-up of a sample from North-East Sardinia using a dense set of autosomal, Y chromosome and mitochondrial markers to assess the potential of the sample for GWAS and fine mapping studies. We genotyped individuals for 500K single-nucleotide polymorphisms, Y chromosome markers and sequenced the mitochondrial hypervariable (HVI–HVII) regions. We identified major haplogroups and compared these with other populations. We estimated linkage disequilibrium (LD) and haplotype diversity across autosomal markers, and compared these with other populations. Our results show that within Sardinia there is no major population substructure and thus it can be considered a genetically homogenous population. We did not find substantial differences in the extent of LD in Sardinians compared with other populations. However, we showed that at least 9% of genomic regions in Sardinians differed in LD structure, which is helpful for identifying functional variants using fine mapping. We concluded that Sardinia is a powerful setting for genetic studies including GWAS and other mapping approaches.
Link
Dissecting the genetic make-up of North-East Sardinia using a large set of haploid and autosomal markers
Luba M Pardo et al.
Abstract
Sardinia has been used for genetic studies because of its historical isolation, genetic homogeneity and increased prevalence of certain rare diseases. Controversy remains concerning the genetic substructure and the extent of genetic homogeneity, which has implications for the design of genome-wide association studies (GWAS). We revisited this issue by examining the genetic make-up of a sample from North-East Sardinia using a dense set of autosomal, Y chromosome and mitochondrial markers to assess the potential of the sample for GWAS and fine mapping studies. We genotyped individuals for 500K single-nucleotide polymorphisms, Y chromosome markers and sequenced the mitochondrial hypervariable (HVI–HVII) regions. We identified major haplogroups and compared these with other populations. We estimated linkage disequilibrium (LD) and haplotype diversity across autosomal markers, and compared these with other populations. Our results show that within Sardinia there is no major population substructure and thus it can be considered a genetically homogenous population. We did not find substantial differences in the extent of LD in Sardinians compared with other populations. However, we showed that at least 9% of genomic regions in Sardinians differed in LD structure, which is helpful for identifying functional variants using fine mapping. We concluded that Sardinia is a powerful setting for genetic studies including GWAS and other mapping approaches.
Link
May 07, 2012
Horse domestication mystery solved (?)
I will add the abstract of the paper later when it is "live" on the PNAS site. For the moment, a link to the press release:
PNAS doi: 10.1073/pnas.1111122109
Reconstructing the origin and spread of horse domestication in the Eurasian steppe
Vera Warmuth et al.
Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA.
Link
New research indicates that domestic horses originated in the steppes of modern-day Ukraine, southwest Russia and west Kazakhstan, mixing with local wild stocks as they spread throughout Europe and Asia. The research was published today, 07 May, in the journal PNAS.ScienceNOW also covers the new research, and reports on a contrasting viewpoint:
For several decades scientists puzzled over the origin of domesticated horses. Based on archaeological evidence, it had long been thought that horse domestication originated in the western part of the Eurasian Steppe (Ukraine, southwest Russia and west Kazakhstan); however, a single origin in a geographically restricted area appeared at odds with the large number of female lineages in the domestic horse gene pool, commonly thought to reflect multiple domestication "events" across a wide geographic area.
In order to solve the perplexing history of the domestic horse, scientists from the University of Cambridge used a genetic database of more than 300 horses sampled from across the Eurasian Steppe to run a number of different modelling scenarios.
Their research shows that the extinct wild ancestor of domestic horses, Equus ferus, expanded out of East Asia approximately 160,000 years ago. They were also able to demonstrate that Equus ferus was domesticated in the western Eurasian Steppe, and that herds were repeatedly restocked with wild horses as they spread across Eurasia.
Not all researchers are convinced, however. Archaeologist Marsha Levine of the University of Cambridge thinks using modern genetic samples to retrace horses' evolution is a dead end. "There's been mixing of cultures and mixing of horses in this region for many thousands of years," she says. "And so when you're looking at any modern horse, you just don't know where it's from."I agree with the idea that ancient DNA will ultimately confirm/reject the model presented in the paper. Of course, it may be the case that the west Eurasian steppe was the place where horse domestication happened, but it is also the place where local horses may be descended from European, West Asian, and Central Asian breeds. I'll have to read the paper to see how the problem of possible admixture between western and eastern horse breeds on the steppe is accounted for in the paper.
Bringing together many kinds of evidence is what will ultimately answer the whens and wheres of horse domestication, Levine says. "What we need to be doing is using material from excavations, sequencing ancient genes, and combining that with what we know from archaeological evidence about how animals were used in the past."
PNAS doi: 10.1073/pnas.1111122109
Reconstructing the origin and spread of horse domestication in the Eurasian steppe
Vera Warmuth et al.
Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and spread of horse domestication in the Eurasian steppes by fitting a spatially explicit stepping-stone model to genotype data from >300 horses sampled across northern Eurasia. We find strong evidence for an expansion of E. ferus out of eastern Eurasia about 160 kya, likely reflecting the colonization of Eurasia by this species. Our best-fitting scenario further suggests that horse domestication originated in the western part of the Eurasian steppe and that domestic herds were repeatedly restocked with local wild horses as they spread out of this area. By showing that horse domestication was initiated in the western Eurasian steppe and that the spread of domestic herds across Eurasia involved extensive introgression from the wild, the scenario of horse domestication proposed here unites evidence from archaeology, mitochondrial DNA, and Y-chromosomal DNA.
Link
May 03, 2012
Bell Beakers from Germany: Y-haplogroup R1b
Just in time with my recent speculations about post-Neolithic events affecting Europe, we now have a paper of a Bell Beaker sample from Germany. Like with earlier Neolithic samples there are two camps in trying to explain the Bell Beaker phenomenon: one of them saw only a cultural phenomenon epitomized by burials with the eponymous Bell Beaker pottery; the other saw a true invading population. This is how Carleton Coon described them:
I will update this entry when I read the paper.
American Journal of Physical Anthropology DOI: 10.1002/ajpa.22074
Emerging genetic patterns of the european neolithic: Perspectives from a late neolithic bell beaker burial site in Germany†
Esther J. Lee et al.
Abstract
The transition from hunting and gathering to agriculture in Europe is associated with demographic changes that may have shifted the human gene pool of the region as a result of an influx of Neolithic farmers from the Near East. However, the genetic composition of populations after the earliest Neolithic, when a diverse mosaic of societies that had been fully engaged in agriculture for some time appeared in central Europe, is poorly known. At this period during the Late Neolithic (ca. 2,800–2,000 BC), regionally distinctive burial patterns associated with two different cultural groups emerge, Bell Beaker and Corded Ware, and may reflect differences in how these societies were organized. Ancient DNA analyses of human remains from the Late Neolithic Bell Beaker site of Kromsdorf, Germany showed distinct mitochondrial haplotypes for six individuals, which were classified under the haplogroups I1, K1, T1, U2, U5, and W5, and two males were identified as belonging to the Y haplogroup R1b. In contrast to other Late Neolithic societies in Europe emphasizing maintenance of biological relatedness in mortuary contexts, the diversity of maternal haplotypes evident at Kromsdorf suggests that burial practices of Bell Beaker communities operated outside of social norms based on shared maternal lineages. Furthermore, our data, along with those from previous studies, indicate that modern U5-lineages may have received little, if any, contribution from the Mesolithic or Neolithic mitochondrial gene pool.
Link
The Dinaric type, with which the Rhenish Bell beakers are associated, is one which entered the western Mediterranean by sea from the east, and eventually moved, by some route yet to be determined in an accurate manner, to the north, and eventually to central Europe.As such, the Bell Beaker phenomenon is a test case for the pots-not-people paradigm. There is ample physical anthropological evidence that the people of Beaker burials had a distinctive physical type which contrasted with the long-headed type typical of the era, so I have always been on the "people" side of the conflict.
I will update this entry when I read the paper.
American Journal of Physical Anthropology DOI: 10.1002/ajpa.22074
Emerging genetic patterns of the european neolithic: Perspectives from a late neolithic bell beaker burial site in Germany†
Esther J. Lee et al.
Abstract
The transition from hunting and gathering to agriculture in Europe is associated with demographic changes that may have shifted the human gene pool of the region as a result of an influx of Neolithic farmers from the Near East. However, the genetic composition of populations after the earliest Neolithic, when a diverse mosaic of societies that had been fully engaged in agriculture for some time appeared in central Europe, is poorly known. At this period during the Late Neolithic (ca. 2,800–2,000 BC), regionally distinctive burial patterns associated with two different cultural groups emerge, Bell Beaker and Corded Ware, and may reflect differences in how these societies were organized. Ancient DNA analyses of human remains from the Late Neolithic Bell Beaker site of Kromsdorf, Germany showed distinct mitochondrial haplotypes for six individuals, which were classified under the haplogroups I1, K1, T1, U2, U5, and W5, and two males were identified as belonging to the Y haplogroup R1b. In contrast to other Late Neolithic societies in Europe emphasizing maintenance of biological relatedness in mortuary contexts, the diversity of maternal haplotypes evident at Kromsdorf suggests that burial practices of Bell Beaker communities operated outside of social norms based on shared maternal lineages. Furthermore, our data, along with those from previous studies, indicate that modern U5-lineages may have received little, if any, contribution from the Mesolithic or Neolithic mitochondrial gene pool.
Link
May 02, 2012
Nature special issue on "Peopling the Planet"
Special issue: Peopling the planet
Link
Not long ago, the story was simple. A vanguard of modern humans left their African birthplace 50,000–60,000 years ago and quickly conquered Asia. They turned left into Europe some 40,000 years ago, later crossing the Bering Strait and marching southward into the Americas. With their advance, Neanderthals and other earlier peoples dwindled and vanished.Nature 485, 23 (03 May 2012) doi:10.1038/485023a
But in the past five years, the picture has grown more complex — and more interesting.
Few question the idea that modern humans are all emigrants from Africa. But when their journey began, when it ended and what they did along the way makes for a deepening mystery, explored in this issue of Nature.
Discoveries on the Arabian peninsula, for example, show that modern humans were camped on the doorstep of Asia more than 100,000 years ago, nearly twice as long ago as anyone thought. If they went farther at that early date — and some archaeologists insist that they must have — their presence would explain a smattering of ambiguous artefacts and fossils around Asia (see page 24).
Elsewhere, humans definitely arrived ahead of schedule. Sensitive new radiocarbon-dating techniques show that the first modern humans reached Europe thousands of years earlier than was thought, implying a lengthy coexistence with Neanderthals there (see page 27). And the picture of big-game hunters following an inland route from Asia to the Americas 13,000 years ago has been obliterated by a barrage of reports of older sites. Archaeologists are studying DNA, ancient and modern, for clues to when and how the first Americans arrived (see page 30).
The most dramatic change, however, concerns the archaic peoples whose world we inherited. In the past two years, ancient-DNA researchers have deciphered the full genome sequences of Neanderthals and a hitherto unknown group called Denisovans, then compared them with modern human genomes. The startling upshot: genetic traces of our vanished cousins live on in people today (see page 33). Just where and how the ancient trysts took place is yet to be revealed, as researchers continue to unravel the human story.
Link
Drawing the human Y chromosome tree with SNPs
Terry, (tdrobb@gmail.com), a poster at GENEALOGY-DNA-L reported age estimates for various nodes of the Y-chromosome tree based on SNPs. These can be found in this PDF file and here (scroll down for UPDATE10). He used 1000 Genomes data and SNP counting to reach these estimates.
It will be nice to see others join in on the SNP bandwagon, because that is really the way forward in age estimation for Y-chromosome lineages. SNPs have an extremely low (=negligible) rate of back-mutation, but they occur at a much lower rate than Y-STR step mutations. On the other hand, there are at most a few hundred Y-STRs and only ~100 tested by commercial companies, while scientific datasets generally include at most a few dozen of them. The Y chromosome includes millions of mutable sites and these will be generally reported both by the 1000 Genomes Project, and the plethora of full genome sequences that is about to become available.
Y-SNP based age estimation has the potential of greatly improving estimates by tightening confidence intervals substantially; there will, of course, be lingering uncertainty of parameters such as generation length, but Y chromosome mutation rates are likely to become very secure once full genome sequencing becomes so cheap that it can be applied to a number of father-son pairs.
Looking at the inferred tree, what is striking is the great distance between haplogroup A1b and the rest of the tree, or about 100,000 years. Note that these are not "relative" estimates as were published by the 1000 Genomes Project (based on "archaeologically" calibrating a node and estimating ages of other nodes by counting the relative number of SNPs), but "absolute" ones (dividing SNPs with a mutation rate).
(UPDATE: There is apparently an even more basal clade than A1b currently investigated; I have removed the link to an announcement regarding this clade, since there are issues regarding the release of this information)
Going back to the age estimates, I cannot help but notice the concordance between Terry's age estimates for DE/CF split (55ky) with the mtDNA estimates for most mtDNA L3 subclades. Terry labels DE "African" and CF "Eurasian", but, in fact DE is Afrasian and "CF" Eurasian. Together with the absence of any evidence for a post-70ka Out-of-Africa, I'd say that it is becoming increasingly clear that while modern humans can be ultimately traced to the Middle Stone Age in Africa, their major expansion that went on to colonize the entire world originated in Asia, and included a major episode of back-migration into Africa.
I also earnestly hope that the next set of Y chromosome papers on recent populations will forego the cost of testing hundreds of samples on Y-STRs and invest in full Y-chromosome sequencing of a few samples after an initial Y-SNP screening.
It will be nice to see others join in on the SNP bandwagon, because that is really the way forward in age estimation for Y-chromosome lineages. SNPs have an extremely low (=negligible) rate of back-mutation, but they occur at a much lower rate than Y-STR step mutations. On the other hand, there are at most a few hundred Y-STRs and only ~100 tested by commercial companies, while scientific datasets generally include at most a few dozen of them. The Y chromosome includes millions of mutable sites and these will be generally reported both by the 1000 Genomes Project, and the plethora of full genome sequences that is about to become available.
Y-SNP based age estimation has the potential of greatly improving estimates by tightening confidence intervals substantially; there will, of course, be lingering uncertainty of parameters such as generation length, but Y chromosome mutation rates are likely to become very secure once full genome sequencing becomes so cheap that it can be applied to a number of father-son pairs.
Looking at the inferred tree, what is striking is the great distance between haplogroup A1b and the rest of the tree, or about 100,000 years. Note that these are not "relative" estimates as were published by the 1000 Genomes Project (based on "archaeologically" calibrating a node and estimating ages of other nodes by counting the relative number of SNPs), but "absolute" ones (dividing SNPs with a mutation rate).
(UPDATE: There is apparently an even more basal clade than A1b currently investigated; I have removed the link to an announcement regarding this clade, since there are issues regarding the release of this information)
Going back to the age estimates, I cannot help but notice the concordance between Terry's age estimates for DE/CF split (55ky) with the mtDNA estimates for most mtDNA L3 subclades. Terry labels DE "African" and CF "Eurasian", but, in fact DE is Afrasian and "CF" Eurasian. Together with the absence of any evidence for a post-70ka Out-of-Africa, I'd say that it is becoming increasingly clear that while modern humans can be ultimately traced to the Middle Stone Age in Africa, their major expansion that went on to colonize the entire world originated in Asia, and included a major episode of back-migration into Africa.
I also earnestly hope that the next set of Y chromosome papers on recent populations will forego the cost of testing hundreds of samples on Y-STRs and invest in full Y-chromosome sequencing of a few samples after an initial Y-SNP screening.