PLoS ONE doi:10.1371/journal.pone.0008901
Altruism in Forest Chimpanzees: The Case of Adoption
Christophe Boesch et al.
Abstract
In recent years, extended altruism towards unrelated group members has been proposed to be a unique characteristic of human societies. Support for this proposal seemingly came from experimental studies on captive chimpanzees that showed that individuals were limited in the ways they shared or cooperated with others. This dichotomy between humans and chimpanzees was proposed to indicate an important difference between the two species, and one study concluded that “chimpanzees are indifferent to the welfare of unrelated group members”. In strong contrast with these captive studies, consistent observations of potentially altruistic behaviors in different populations of wild chimpanzees have been reported in such different domains as food sharing, regular use of coalitions, cooperative hunting and border patrolling. This begs the question of what socio-ecological factors favor the evolution of altruism. Here we report 18 cases of adoption, a highly costly behavior, of orphaned youngsters by group members in Taï forest chimpanzees. Half of the adoptions were done by males and remarkably only one of these proved to be the father. Such adoptions by adults can last for years and thus imply extensive care towards the orphans. These observations reveal that, under the appropriate socio-ecologic conditions, chimpanzees do care for the welfare of other unrelated group members and that altruism is more extensive in wild populations than was suggested by captive studies.
Link
January 31, 2010
January 29, 2010
Mongoloid mtDNA in Imperial-era Italy
Ambassador or slave? East Asian skeleton discovered in Vagnari Roman Cemetery
A team of researchers announced a surprising discovery during a scholarly presentation in Toronto last Friday. The research team, based at McMaster University in Hamilton, Canada, has been helping to excavate an ancient Roman cemetery at the site of Vagnari in southern Italy. Led by Professor Tracy Prowse, they’ve been analyzing the skeletons found there by performing DNA and oxygen isotope tests.
The surprise is that the DNA tests show that one of the skeletons, a man, has an East Asian ancestry – on his mother’s side. This appears to be the first time that a skeleton with an East Asian ancestry has been discovered in the Roman Empire.
...
The man with East Asian ancestry may well have been a slave himself. He lived sometime in the first to second century AD, in the early days of the Roman Empire. Much of his skeleton (pictured here) has not survived. The man’s surviving grave goods consist of a single pot (which archaeologists used to date the burial). To top things off someone was buried on top of him - with a superior collection of grave goods.
...
The researchers determined his ancestry by analyzing his mitochondrial DNA – material that is passed down from mother to offspring.
As DNA is passed down from generation to generation there are mutations. People who are related to each other will have similar changes – allowing researchers to put them into broad “haplogroups,” that tend to relate to geographical areas.
This technique has been used to map the spread of humans throughout the world.
The man found in the cemetery has DNA that belongs to what scientists called haplogroup D. “The haplogroup itself has this East Asian origin, it’s not something that’s found in past European populations - the origin of this haplogroup is East Asia,” said Dr. Barta.
January 26, 2010
Ancient DNA from frozen Yakuts
From the paper:
Human evolution in Siberia: from frozen bodies to ancient DNA
Eric Crubezy et al.
Abstract (provisional)
Background
The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. precise origin of paternal lineages and admixture rate with indigenous populations). This study attempts to better understand the origins of the Yakuts, by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia).
Results
High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies, helped us to clarify the microevolution of this intriguing population.
Conclusion
We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baikal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today.
Link (pdf)
Sixty one percent (8 out of 13) of the haplotypes (Ht1, Ht2, Yaka56, 65, 71, 80, 81, 86) were affiliated to the N1c (TAT-C) haplogroup on the basis of the SNP analyses. This haplogroup is considered as the most frequent in the Yakut population, and its frequency varies across studies from 75% [12] to 100% [13]. Sample YAKa26 was affiliated to haplogroups K . The SNP typing was inconclusive for 5 individuals (YAKa17, 19, 47, 49 and 57); nevertheless the affiliation to N1c was excluded on the basis of the absence of the TAT-C mutation.and:
The origin of the most frequent Y-chromosomal haplotypes (Ht1 and Ht2) was difficult to establish on the basis of genetic information. Indeed, these two lineages belonging to haplogroup N1c seem to be restricted to Yakut populations, and were probably present since the period they were first located in Central Yakutia. Interestingly, the comparison with archaeological data revealed that the male individuals (YAKa34, 39, 40, 69, 78) at the beginning of the 18th century, identified as Clan Chiefs (or tojons) on the basis of their grave goods (weapons, jewelry, silk clothes, richly ornamented saddles and signet rings), belonged to these two haplotypes. Therefore, archaeological data could bring interesting information in tracing back the origin of these enigmatic male lineages. Indeed, the grave goods of the 15th/17th centuries (weapons and horse harnesses) and the construction of coffins with an empty trunk from the 18th century are similar to the burial customs of the Cis-Baïkal area [44] and of the Egyin Gol Necropolis during the 3rd century BC [45-47]. This suggests that the male ancestors of the Yakuts were probably formed of a small group of horse-riders originating from Northern Mongolia or the Baïkal Lake.and:
Based on the analyses of the maternal and paternal lineages of ancient Yakuts, we were able to demonstrate that the formation of this population started before the 15th century, with a small group of settlers composed of horse-riders from the Cis-Baïkal region and a small number of women from different South Siberian origins.BMC Evolutionary Biology doi:10.1186/1471-2148-10-25
Human evolution in Siberia: from frozen bodies to ancient DNA
Eric Crubezy et al.
Abstract (provisional)
Background
The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. precise origin of paternal lineages and admixture rate with indigenous populations). This study attempts to better understand the origins of the Yakuts, by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia).
Results
High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies, helped us to clarify the microevolution of this intriguing population.
Conclusion
We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baikal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today.
Link (pdf)
January 25, 2010
Migrants introduced farming to Britain
Journal of Archaeological Science doi:10.1016/j.jas.2009.11.016
Radiocarbon evidence indicates that migrants introduced farming to Britain
Mark Collard
Abstract
Archaeologists disagree about how farming began in Britain. Some argue it was a result of indigenous groups adopting domesticates and cultigens via trade and exchange. Others contend it was the consequence of a migration of farmers from mainland Europe. To shed light on this debate, we used radiocarbon dates to estimate changes in population density between 8000 and 4000 cal BP. We found evidence for a marked and rapid increase in population density coincident with the appearance of cultigens around 6000 cal BP. We also found evidence that this increase occurred first in southern England and shortly afterwards in central Scotland. These findings are best explained by groups of farmers from the Continent independently colonizing England and Scotland, and therefore strongly support the migrant farmers hypothesis.
Link
Radiocarbon evidence indicates that migrants introduced farming to Britain
Mark Collard
Abstract
Archaeologists disagree about how farming began in Britain. Some argue it was a result of indigenous groups adopting domesticates and cultigens via trade and exchange. Others contend it was the consequence of a migration of farmers from mainland Europe. To shed light on this debate, we used radiocarbon dates to estimate changes in population density between 8000 and 4000 cal BP. We found evidence for a marked and rapid increase in population density coincident with the appearance of cultigens around 6000 cal BP. We also found evidence that this increase occurred first in southern England and shortly afterwards in central Scotland. These findings are best explained by groups of farmers from the Continent independently colonizing England and Scotland, and therefore strongly support the migrant farmers hypothesis.
Link
January 22, 2010
Caucasoid mtDNA U3 and X2 in Taklamakan Desert
Related:
Early Eurasian migration traces in the Tarim Basin revealed by mtDNA polymorphisms
Yinqiu Cui et al.
Abstract
The mitochondrial DNA (mtDNA) polymorphisms of 58 samples from the Daheyan village located in the central Taklamakan Desert of the Tarim Basin were determined in this study. Among the 58 samples, 29 haplotypes belonging to 18 different haplogroups were analyzed. Almost all the mtDNAs belong to a subset of either the defined Western or Eastern Eurasian pool. Extensive Eastern Eurasian lineages exist in the Daheyan population in which Northern-prevalent haplogroups present higher frequencies. In the limited existing Western Eurasian lineages, two sub-haplogroups, U3 and X2, that are rare in Central Asia were found in this study, which may be indicative of the remnants of an early immigrant population from the Near East and Caucasus regions preserved only in the Tarim Basin. The presence of U3 in modern and archeological samples in the Tarim Basin suggests that the immigration took place earlier than 2,000 years ago and points to human continuity in this area, with at least one Western lineage originating from the Near East and Caucasus regions.
Link
- Some mtDNA links between Europe and Asia
- Ancient mtDNA from Sampula population in Xinjiang
- mtDNA evidence for Caucasoid-Mongoloid admixture in Xinjiang 2,500 years ago
- mtDNA from Xinjiang
Early Eurasian migration traces in the Tarim Basin revealed by mtDNA polymorphisms
Yinqiu Cui et al.
Abstract
The mitochondrial DNA (mtDNA) polymorphisms of 58 samples from the Daheyan village located in the central Taklamakan Desert of the Tarim Basin were determined in this study. Among the 58 samples, 29 haplotypes belonging to 18 different haplogroups were analyzed. Almost all the mtDNAs belong to a subset of either the defined Western or Eastern Eurasian pool. Extensive Eastern Eurasian lineages exist in the Daheyan population in which Northern-prevalent haplogroups present higher frequencies. In the limited existing Western Eurasian lineages, two sub-haplogroups, U3 and X2, that are rare in Central Asia were found in this study, which may be indicative of the remnants of an early immigrant population from the Near East and Caucasus regions preserved only in the Tarim Basin. The presence of U3 in modern and archeological samples in the Tarim Basin suggests that the immigration took place earlier than 2,000 years ago and points to human continuity in this area, with at least one Western lineage originating from the Near East and Caucasus regions.
Link
January 21, 2010
R1a1/U2e male in 2,000-year old Mongolian Xiongnu
Related:
A western Eurasian male is found in 2000-year-old elite Xiongnu cemetery in Northeast Mongolia
Kijeong Kim et al.
Abstract
We analyzed mitochondrial DNA (mtDNA), Y-chromosome single nucleotide polymorphisms (Y-SNP), and autosomal short tandem repeats (STR) of three skeletons found in a 2,000-year-old Xiongnu elite cemetery in Duurlig Nars of Northeast Mongolia. This study is one of the first reports of the detailed genetic analysis of ancient human remains using the three types of genetic markers. The DNA analyses revealed that one subject was an ancient male skeleton with maternal U2e1 and paternal R1a1 haplogroups. This is the first genetic evidence that a male of distinctive Indo-European lineages (R1a1) was present in the Xiongnu of Mongolia. This might indicate an Indo-European migration into Northeast Asia 2,000 years ago. Other specimens are a female with mtDNA haplogroup D4 and a male with Y-SNP haplogroup C3 and mtDNA haplogroup D4. Those haplogroups are common in Northeast Asia. There was no close kinship among them. The genetic evidence of U2e1 and R1a1 may help to clarify the migration patterns of Indo-Europeans and ancient East-West contacts of the Xiongnu Empire. Artifacts in the tombs suggested that the Xiongnu had a system of the social stratification. The West Eurasian male might show the racial tolerance of the Xiongnu Empire and some insight into the Xiongnu society.
Link
- Some mtDNA links between Europe and Asia
- 30,000 year old mtDNA haplogroup U2 from Kostenki
- More on prehistoric South Siberians (Keyser et al. 2009)
A western Eurasian male is found in 2000-year-old elite Xiongnu cemetery in Northeast Mongolia
Kijeong Kim et al.
Abstract
We analyzed mitochondrial DNA (mtDNA), Y-chromosome single nucleotide polymorphisms (Y-SNP), and autosomal short tandem repeats (STR) of three skeletons found in a 2,000-year-old Xiongnu elite cemetery in Duurlig Nars of Northeast Mongolia. This study is one of the first reports of the detailed genetic analysis of ancient human remains using the three types of genetic markers. The DNA analyses revealed that one subject was an ancient male skeleton with maternal U2e1 and paternal R1a1 haplogroups. This is the first genetic evidence that a male of distinctive Indo-European lineages (R1a1) was present in the Xiongnu of Mongolia. This might indicate an Indo-European migration into Northeast Asia 2,000 years ago. Other specimens are a female with mtDNA haplogroup D4 and a male with Y-SNP haplogroup C3 and mtDNA haplogroup D4. Those haplogroups are common in Northeast Asia. There was no close kinship among them. The genetic evidence of U2e1 and R1a1 may help to clarify the migration patterns of Indo-Europeans and ancient East-West contacts of the Xiongnu Empire. Artifacts in the tombs suggested that the Xiongnu had a system of the social stratification. The West Eurasian male might show the racial tolerance of the Xiongnu Empire and some insight into the Xiongnu society.
Link
January 20, 2010
Y-haplogroup prediction software accuracy tested
The authors tested Athey's Haplogroup Predictor and the University of Arizona Haplogroup Classifier.
From the paper:
Int J Legal Med. 2010 Jan 15. [Epub ahead of print]
Muzzio M, Ramallo V, Motti JM, Santos MR, López Camelo JS, Bailliet G.
The development of online software designed for genetic studies has been exponentially growing, providing numerous benefits to the scientific community. However, they should be used with care, since some require adjustments. The efficiency of two programs for haplogroup prediction was tested with 119 samples of known haplotypes and haplogroups from Argentine populations. Quantitative estimates of the predictive quality of both software systems were computed with the uncertainty coefficient; and sensitivity, specificity, positive, and negative likelihood ratios were also calculated to assert the reliability of both programs, showing high probabilities of assigning an incorrect haplogroup.
Link
From the paper:
These results represent a high probability of error, and a bias towards the R* haplogroup, so it is most likely that results based on the haplogroup predictions of these software systems are weakened. For cases in which sex bias in multiethnic populations is estimated by this method, an overestimation of the European component is expected. Haplogroup determination by SNP analysis remains the best approach, considering the low reliability of prediction of software available.This is a very important result, as haplogroup prediction software has sometimes been applied to large collections of Y-STR haplotypes found in the forensic literature. It is important to be cautious about its use, especially for short haplotypes.
The adequate LR+ for the Q1a3a and DE haplogroups could be explained by a lower diversity within each group. Especially in the Q1a3a case, which is a relatively recent haplogroup, the homogeneity is the result of its young evolutionary age, given that the time lapse in which the haplotypes spread away from the haplogroup founder is rather short [14].
Int J Legal Med. 2010 Jan 15. [Epub ahead of print]
Software for Y-haplogroup predictions: a word of caution.
Muzzio M, Ramallo V, Motti JM, Santos MR, López Camelo JS, Bailliet G.
The development of online software designed for genetic studies has been exponentially growing, providing numerous benefits to the scientific community. However, they should be used with care, since some require adjustments. The efficiency of two programs for haplogroup prediction was tested with 119 samples of known haplotypes and haplogroups from Argentine populations. Quantitative estimates of the predictive quality of both software systems were computed with the uncertainty coefficient; and sensitivity, specificity, positive, and negative likelihood ratios were also calculated to assert the reliability of both programs, showing high probabilities of assigning an incorrect haplogroup.
Link
Neolithic origin of European Y chromosomes
My comments on this important paper will follow here after I read it.
UPDATE
My observations:
Related: Migrationism Strikes Back in which I argue in favor of Neolithic (or later) replacement of most European mtDNA.
PLoS Biology doi:10.1371/journal.pbio.1000285
A Predominantly Neolithic Origin for European Paternal Lineages
Patricia Balaresque et al.
Abstract
The relative contributions to modern European populations of Paleolithic hunter-gatherers and Neolithic farmers from the Near East have been intensely debated. Haplogroup R1b1b2 (R-M269) is the commonest European Y-chromosomal lineage, increasing in frequency from east to west, and carried by 110 million European men. Previous studies suggested a Paleolithic origin, but here we show that the geographical distribution of its microsatellite diversity is best explained by spread from a single source in the Near East via Anatolia during the Neolithic. Taken with evidence on the origins of other haplogroups, this indicates that most European Y chromosomes originate in the Neolithic expansion. This reinterpretation makes Europe a prime example of how technological and cultural change is linked with the expansion of a Y-chromosomal lineage, and the contrast of this pattern with that shown by maternally inherited mitochondrial DNA suggests a unique role for males in the transition.
Link
UPDATE
My observations:
- The non-use by the paper of the "evolutionary mutation rate" results in low age estimates and hence a "Neolithic" time frame. The authors are to be commended for going against the flow of the last 7 years of population genetics literature.
- However, the inference that a "Neolithic" TMRCA = "Neolithic" time of arrival into Europe is flawed, as I have argued elsewhere. In short: a particular TMRCA is consistent with either the arrival of the lineage long before and long after the TMRCA in a particular geographical area.
- Equally flawed is the inference that R1b1b2 is clinal (Figure 2A). Microsatellite variance is not significantly higher in Turkey than in Europe -- even if one makes the questionable questionable assumption that modern Anatolian Turks are patrilineal descendants of Neolithic Anatolians. The significance of the regression line disappears if 1 or 2 data points are excluded, and the plot has a quite visible "gap" between Turkey and Italy corresponding to the entirety of eastern Europe and the Balkans, i.e. the routes that any putative Neolithic lineages would have entered Europe
Related: Migrationism Strikes Back in which I argue in favor of Neolithic (or later) replacement of most European mtDNA.
PLoS Biology doi:10.1371/journal.pbio.1000285
A Predominantly Neolithic Origin for European Paternal Lineages
Patricia Balaresque et al.
Abstract
The relative contributions to modern European populations of Paleolithic hunter-gatherers and Neolithic farmers from the Near East have been intensely debated. Haplogroup R1b1b2 (R-M269) is the commonest European Y-chromosomal lineage, increasing in frequency from east to west, and carried by 110 million European men. Previous studies suggested a Paleolithic origin, but here we show that the geographical distribution of its microsatellite diversity is best explained by spread from a single source in the Near East via Anatolia during the Neolithic. Taken with evidence on the origins of other haplogroups, this indicates that most European Y chromosomes originate in the Neolithic expansion. This reinterpretation makes Europe a prime example of how technological and cultural change is linked with the expansion of a Y-chromosomal lineage, and the contrast of this pattern with that shown by maternally inherited mitochondrial DNA suggests a unique role for males in the transition.
Link
January 19, 2010
Genetic Covariation Between Brain Volumes and IQ, Reading Performance, and Processing Speed (Betjemann et al. 2010)
Related:
Genetic Covariation Between Brain Volumes and IQ, Reading Performance, and Processing Speed.
Betjemann RS, Johnson EP, Barnard H, Boada R, Filley CM, Filipek PA, Willcutt EG, Defries JC, Pennington BF.
Although there has been much interest in the relation between brain size and cognition, few studies have investigated this relation within a genetic framework and fewer still in non-adult samples. We analyzed the genetic and environmental covariance between structural MRI data from four brain regions (total brain volume, neocortex, white matter, and prefrontal cortex), and four cognitive measures (verbal IQ (VIQ), performance IQ (PIQ), reading ability, and processing speed), in a sample of 41 MZ twin pairs and 30 same-sex DZ twin pairs (mean age at cognitive test = 11.4 years; mean age at scan = 15.4 years). Multivariate Cholesky decompositions were performed with each brain volume measure entered first, followed by the four cognitive measures. Consistent with previous research, each brain and cognitive measure was found to be significantly heritable. The novel finding was the significant genetic but not environmental covariance between brain volumes and cognitive measures. Specifically, PIQ shared significant common genetic variance with all four measures of brain volume (r (g) = .58-.82). In contrast, VIQ shared significant genetic influence with neocortex volume only (r (g) = .58). Processing speed was significant with total brain volume (r (g) = .79), neocortex (r (g) = .64), and white matter (r (g) = .89), but not prefrontal cortex. The only brain measure to share genetic influence with reading was total brain volume (r (g) = .32), which also shared genetic influences with processing speed.
Link
Although there has been much interest in the relation between brain size and cognition, few studies have investigated this relation within a genetic framework and fewer still in non-adult samples. We analyzed the genetic and environmental covariance between structural MRI data from four brain regions (total brain volume, neocortex, white matter, and prefrontal cortex), and four cognitive measures (verbal IQ (VIQ), performance IQ (PIQ), reading ability, and processing speed), in a sample of 41 MZ twin pairs and 30 same-sex DZ twin pairs (mean age at cognitive test = 11.4 years; mean age at scan = 15.4 years). Multivariate Cholesky decompositions were performed with each brain volume measure entered first, followed by the four cognitive measures. Consistent with previous research, each brain and cognitive measure was found to be significantly heritable. The novel finding was the significant genetic but not environmental covariance between brain volumes and cognitive measures. Specifically, PIQ shared significant common genetic variance with all four measures of brain volume (r (g) = .58-.82). In contrast, VIQ shared significant genetic influence with neocortex volume only (r (g) = .58). Processing speed was significant with total brain volume (r (g) = .79), neocortex (r (g) = .64), and white matter (r (g) = .89), but not prefrontal cortex. The only brain measure to share genetic influence with reading was total brain volume (r (g) = .32), which also shared genetic influences with processing speed.
Link
January 17, 2010
Height-IQ-Gender interplay
Am J Psychol. 2009 Winter;122(4):527-36.
The role of height in the sex difference in intelligence.
The role of height in the sex difference in intelligence.
Kanazawa S, Reyniers DJ.
Recent studies conclude that men on average have higher intelligence than women by 3-5 IQ points. However, the ultimate evolutionary question of why men should have evolved to have higher intelligence than women remains. We suggest that men may have slightly higher intelligence than women through 4 mechanisms: (1) assortative mating of intelligent men and beautiful women, (2) assortative mating of tall men and beautiful women, (3) an extrinsic correlation between height and intelligence produced by Mechanisms 1 and 2, and (4) a higher-than-expected offspring sex ratio (more sons) among tall (and hence intelligent) parents. Consistent with our suggestion, we show that men may have higher IQs than women because they are taller, and once we control for height women have slightly higher IQs than men.The correlation between height and IQ and the female advantage in intelligence persist even after we control for health as a measure of genetic quality, as well as physical attractiveness, age, race, education, and earnings. Height is also strongly associated with intelligence within each sex.
Recent studies conclude that men on average have higher intelligence than women by 3-5 IQ points. However, the ultimate evolutionary question of why men should have evolved to have higher intelligence than women remains. We suggest that men may have slightly higher intelligence than women through 4 mechanisms: (1) assortative mating of intelligent men and beautiful women, (2) assortative mating of tall men and beautiful women, (3) an extrinsic correlation between height and intelligence produced by Mechanisms 1 and 2, and (4) a higher-than-expected offspring sex ratio (more sons) among tall (and hence intelligent) parents. Consistent with our suggestion, we show that men may have higher IQs than women because they are taller, and once we control for height women have slightly higher IQs than men.The correlation between height and IQ and the female advantage in intelligence persist even after we control for health as a measure of genetic quality, as well as physical attractiveness, age, race, education, and earnings. Height is also strongly associated with intelligence within each sex.
January 16, 2010
Democrats and Republicans really do look different
It would be really neat if someone did a facial composite of the average Democrat/Republican using e.g., all Caucasoid US senators belonging to either party.
I think it's fairly easy to distinguish between Greek politicians belonging to different parties as well. Here's my guide to some typical traits of Greek politicians (of course there are numerous exceptions):
Right-wing: regular suit and tie, shaved, "managerial" look
Center-left: higher probability of sporting a mustache
Communists: never wear ties, usually shaved, "faux-proletarian" look
Radical Left: never wear ties, higher probability of being unshaved, "leftist-intellectual" look
Extra-parliamentary left: never wear ties, unshaved, unkempt hair, "revolutionary" Che Guevara wannabes
PLoS ONE doi:http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008733
Democrats and Republicans Can Be Differentiated from Their Faces
Nicholas O. Rule, Nalini Ambady
Abstract
Background
Individuals' faces communicate a great deal of information about them. Although some of this information tends to be perceptually obvious (such as race and sex), much of it is perceptually ambiguous, without clear or obvious visual cues.
Methodology/Principal Findings
Here we found that individuals' political affiliations could be accurately discerned from their faces. In Study 1, perceivers were able to accurately distinguish whether U.S. Senate candidates were either Democrats or Republicans based on photos of their faces. Study 2 showed that these effects extended to Democrat and Republican college students, based on their senior yearbook photos. Study 3 then showed that these judgments were related to differences in perceived traits among the Democrat and Republican faces. Republicans were perceived as more powerful than Democrats. Moreover, as individual targets were perceived to be more powerful, they were more likely to be perceived as Republicans by others. Similarly, as individual targets were perceived to be warmer, they were more likely to be perceived as Democrats.
Conclusions/Significance
These data suggest that perceivers' beliefs about who is a Democrat and Republican may be based on perceptions of traits stereotypically associated with the two political parties and that, indeed, the guidance of these stereotypes may lead to categorizations of others' political affiliations at rates significantly more accurate than chance guessing.
Link
PLoS ONE doi:http://www.plosone.org/article/info:doi/10.1371/journal.pone.0008733
Democrats and Republicans Can Be Differentiated from Their Faces
Nicholas O. Rule, Nalini Ambady
Abstract
Background
Individuals' faces communicate a great deal of information about them. Although some of this information tends to be perceptually obvious (such as race and sex), much of it is perceptually ambiguous, without clear or obvious visual cues.
Methodology/Principal Findings
Here we found that individuals' political affiliations could be accurately discerned from their faces. In Study 1, perceivers were able to accurately distinguish whether U.S. Senate candidates were either Democrats or Republicans based on photos of their faces. Study 2 showed that these effects extended to Democrat and Republican college students, based on their senior yearbook photos. Study 3 then showed that these judgments were related to differences in perceived traits among the Democrat and Republican faces. Republicans were perceived as more powerful than Democrats. Moreover, as individual targets were perceived to be more powerful, they were more likely to be perceived as Republicans by others. Similarly, as individual targets were perceived to be warmer, they were more likely to be perceived as Democrats.
Conclusions/Significance
These data suggest that perceivers' beliefs about who is a Democrat and Republican may be based on perceptions of traits stereotypically associated with the two political parties and that, indeed, the guidance of these stereotypes may lead to categorizations of others' political affiliations at rates significantly more accurate than chance guessing.
Link
Human-chimp Y chromosomes widely divergent
John Hawks covers this important story in detail.
Nature doi:0.1038/nature08700
Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content
Jennifer F. Hughes et al.
The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome1, 2. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis3, 4. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes5, 6, 7, 8, but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, achieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically in sequence structure and gene content, indicating rapid evolution during the past 6 million years. The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. Although genetic decay may be the principal dynamic in the evolution of newly emergent Y chromosomes, wholesale renovation is the paramount theme in the continuing evolution of chimpanzee, human and perhaps other older MSYs.
Link
Nature doi:0.1038/nature08700
Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content
Jennifer F. Hughes et al.
The human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome1, 2. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis3, 4. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes5, 6, 7, 8, but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, achieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically in sequence structure and gene content, indicating rapid evolution during the past 6 million years. The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. Although genetic decay may be the principal dynamic in the evolution of newly emergent Y chromosomes, wholesale renovation is the paramount theme in the continuing evolution of chimpanzee, human and perhaps other older MSYs.
Link
January 14, 2010
Origin of Northern Israel Mycenaean pottery in the Argolid (Peloponnese)
Journal of Archaeological Science
Volume 37, Issue 2, February 2010, Pages 409-416
A provenance study of Mycenaean pottery from Northern Israel
Sharon Zuckerman
Abstract
The occurrence of imported Mycenaean pottery in the Late Bronze Age southern Levant is one of the most conspicuous aspects of Eastern Mediterranean trade connections during this period. A group of 183 Mycenaean pottery vessels from 14 sites in northern Israel, from both coastal and inland settlement contexts were analyzed by Neutron Activation Analysis. The results indicate that the vast majority of these vessels have a similar profile and can be provenanced to the north-eastern Peloponnese or more specifically, to the Mycenae/Berbati workshop in the Argolid. Possible interpretations of these results are presented and discussed against the historical and cultural background of the Late Bronze Age Eastern Mediterranean.
Link
Volume 37, Issue 2, February 2010, Pages 409-416
A provenance study of Mycenaean pottery from Northern Israel
Sharon Zuckerman
Abstract
The occurrence of imported Mycenaean pottery in the Late Bronze Age southern Levant is one of the most conspicuous aspects of Eastern Mediterranean trade connections during this period. A group of 183 Mycenaean pottery vessels from 14 sites in northern Israel, from both coastal and inland settlement contexts were analyzed by Neutron Activation Analysis. The results indicate that the vast majority of these vessels have a similar profile and can be provenanced to the north-eastern Peloponnese or more specifically, to the Mycenae/Berbati workshop in the Argolid. Possible interpretations of these results are presented and discussed against the historical and cultural background of the Late Bronze Age Eastern Mediterranean.
Link
January 13, 2010
Another Four Composites: guess their origin
ANSWER (15/1/2010):
Israeli, Polish
Portuguese, Hungarian
END ANSWER
January 11, 2010
Guess the origin of these four composites
ANSWER (15/1/2010):
Russian, Cypriot
Romanian, Spanish
END ANSWER
You can guess their country of origin, language group (e.g., Slavic, Germanic, Romance, Finno-Ugrian, Greek, etc.), geographical origin (N/S/W/E Europe or W/S/C Asia), or whatever else you can intuit about them.
January 02, 2010
R-V88 and migration of Chadic speakers across the Sahara
The presence of R1b chromosomes in Africa is one of a few Y-chromosome phylogeographic anomalies I noted long ago. This new paper offers an insight into the migration of these chromosomes along with the Chadic branch of Afroasiatic from Asia to Europe. More on this after I read the paper.
European Journal of Human Genetics doi:10.1038/ejhg.2009.231
Human Y chromosome haplogroup R-V88: a paternal genetic record of early mid Holocene trans-Saharan connections and the spread of Chadic languages
Fulvio Cruciani et al.
Abstract
Although human Y chromosomes belonging to haplogroup R1b are quite rare in Africa, being found mainly in Asia and Europe, a group of chromosomes within the paragroup R-P25* are found concentrated in the central-western part of the African continent, where they can be detected at frequencies as high as 95%. Phylogenetic evidence and coalescence time estimates suggest that R-P25* chromosomes (or their phylogenetic ancestor) may have been carried to Africa by an Asia-to-Africa back migration in prehistoric times. Here, we describe six new mutations that define the relationships among the African R-P25* Y chromosomes and between these African chromosomes and earlier reported R-P25 Eurasian sub-lineages. The incorporation of these new mutations into a phylogeny of the R1b haplogroup led to the identification of a new clade (R1b1a or R-V88) encompassing all the African R-P25* and about half of the few European/west Asian R-P25* chromosomes. A worldwide phylogeographic analysis of the R1b haplogroup provided strong support to the Asia-to-Africa back-migration hypothesis. The analysis of the distribution of the R-V88 haplogroup in >1800 males from 69 African populations revealed a striking genetic contiguity between the Chadic-speaking peoples from the central Sahel and several other Afroasiatic-speaking groups from North Africa. The R-V88 coalescence time was estimated at 9200–5600 kya, in the early mid Holocene. We suggest that R-V88 is a paternal genetic record of the proposed mid-Holocene migration of proto-Chadic Afroasiatic speakers through the Central Sahara into the Lake Chad Basin, and geomorphological evidence is consistent with this view.
Link
UPDATE (8/1/10):
The paper, to its credit acknowledges that the "effective mutation rate" depends on population growth history as I have argued a year and a half ago. The authors write:
As I noted in haplogroup sizes and observation selection effects haplogroup sizes provide a sanity check to assumptions about population growth history:
Owing to the uncertainties associated with the estimate of the evolutionary effective microsatellite mutationrates, depending on the haplogroup demographic history,37 we considered two different population models: (1) a constant size population and (2) a single rate of m=0.01 for exponential population growth. After calibration for the specificmicrosatellites used in this study,13 we found evolutionary effective mutationrates of 7.9x10-4 and 1.3x10-3, respectively.and:
As an upper limit, we used the coalescence time of the R-M343/P25 haplogroup (12.9 ky, 95% CI=11.6–14.3 ky, under a conservative scenario of constant population size), which, on the basis of the accumulated nucleotide and microsatellite diversity (Table 1; Figure 2), most likely originated outside Africa. The coalescence time of the seemingly African-specific haplogroup R-V69 (6.0 ky, 95% CI=4.2–8.2 ky, under the hypothesis of an expanding population) was used as a lower limit.
Haplogroups do not reach commonly-observed present-day sizes under the assumption of constant population size. Inferences of age based on such an assumption are a very conservative upper limit. However, the assumption of m=0.01 also does not result in "large" present day haplogroups (see previous link).
Thus, I suppose that the age of R-V88 is younger than 4.2–8.2 ky, and could be as young as ~3-4ky in a rapidly expanding population. To determine how fast R-V88 actually grew, we must take into account its present-day demographic size (how many people in the world now possess it). The final estimate must be consistent with both the demographic size and the current Y-STR variance.
I don't have data on R-V88 prevalence today, but it really doesn't take a very large haplogroup in order to infer a very fast growth rate, and a Y-STR variance accumulation rate (effective rate) close to the germline one. Therefore, I am guessing that R-V88 is also one of a growing palette of haplogroups that expanded during the Bronze Age.
European Journal of Human Genetics doi:10.1038/ejhg.2009.231
Human Y chromosome haplogroup R-V88: a paternal genetic record of early mid Holocene trans-Saharan connections and the spread of Chadic languages
Fulvio Cruciani et al.
Abstract
Although human Y chromosomes belonging to haplogroup R1b are quite rare in Africa, being found mainly in Asia and Europe, a group of chromosomes within the paragroup R-P25* are found concentrated in the central-western part of the African continent, where they can be detected at frequencies as high as 95%. Phylogenetic evidence and coalescence time estimates suggest that R-P25* chromosomes (or their phylogenetic ancestor) may have been carried to Africa by an Asia-to-Africa back migration in prehistoric times. Here, we describe six new mutations that define the relationships among the African R-P25* Y chromosomes and between these African chromosomes and earlier reported R-P25 Eurasian sub-lineages. The incorporation of these new mutations into a phylogeny of the R1b haplogroup led to the identification of a new clade (R1b1a or R-V88) encompassing all the African R-P25* and about half of the few European/west Asian R-P25* chromosomes. A worldwide phylogeographic analysis of the R1b haplogroup provided strong support to the Asia-to-Africa back-migration hypothesis. The analysis of the distribution of the R-V88 haplogroup in >1800 males from 69 African populations revealed a striking genetic contiguity between the Chadic-speaking peoples from the central Sahel and several other Afroasiatic-speaking groups from North Africa. The R-V88 coalescence time was estimated at 9200–5600 kya, in the early mid Holocene. We suggest that R-V88 is a paternal genetic record of the proposed mid-Holocene migration of proto-Chadic Afroasiatic speakers through the Central Sahara into the Lake Chad Basin, and geomorphological evidence is consistent with this view.
Link
30,000 year old mtDNA haplogroup U2 from Kostenki
The discovery ties in well with my thoughts in Migrationism Strikes Back. Indeed it ties in well with some of my comments in that post to the effect that the late European foragers tested recently (who belonged to mtDNA haplogroup U) were not significantly different from the earlier hunter-gatherers of Europe. So, we have continuity of U-types in Europe across tens of thousands of years, interrupted by the Neolithic ander latintrogression of the full package of modern Caucasoid haplogroups (the so-called other "Daughters of Eve").
The BBC has a story.
Current Biology doi:10.1016/j.cub.2009.11.068
A Complete mtDNA Genome of an Early Modern Human from Kostenki, Russia
Johannes Krause et al.
Abstract
The recovery of DNA sequences from early modern humans (EMHs) could shed light on their interactions with archaic groups such as Neandertals and their relationships to current human populations. However, such experiments are highly problematic because present-day human DNA frequently contaminates bones [1,2]. For example, in a recent study of mitochondrial (mt) DNA from Neolithic European skeletons, sequence variants were only taken as authentic if they were absent or rare in the present population, whereas others had to be discounted as possible contamination [3,4]. This limits analysis to EMH individuals carrying rare sequences and thus yields a biased view of the ancient gene pool. Other approaches of identifying contaminating DNA, such as genotyping all individuals who have come into contact with a sample, restrict analyses to specimens where this is possible [5,6] and do not exclude all possible sources of contamination. By studying mtDNA in Neandertal remains, where contamination and endogenous DNA can be distinguished by sequence, we show that fragmentation patterns and nucleotide misincorporations can be used to gauge authenticity of ancient DNA sequences. We use these features to determine a complete mtDNA sequence from a ∼30,000-year-old EMH from the Kostenki 14 site in Russia.
Link
The BBC has a story.
Current Biology doi:10.1016/j.cub.2009.11.068
A Complete mtDNA Genome of an Early Modern Human from Kostenki, Russia
Johannes Krause et al.
Abstract
The recovery of DNA sequences from early modern humans (EMHs) could shed light on their interactions with archaic groups such as Neandertals and their relationships to current human populations. However, such experiments are highly problematic because present-day human DNA frequently contaminates bones [1,2]. For example, in a recent study of mitochondrial (mt) DNA from Neolithic European skeletons, sequence variants were only taken as authentic if they were absent or rare in the present population, whereas others had to be discounted as possible contamination [3,4]. This limits analysis to EMH individuals carrying rare sequences and thus yields a biased view of the ancient gene pool. Other approaches of identifying contaminating DNA, such as genotyping all individuals who have come into contact with a sample, restrict analyses to specimens where this is possible [5,6] and do not exclude all possible sources of contamination. By studying mtDNA in Neandertal remains, where contamination and endogenous DNA can be distinguished by sequence, we show that fragmentation patterns and nucleotide misincorporations can be used to gauge authenticity of ancient DNA sequences. We use these features to determine a complete mtDNA sequence from a ∼30,000-year-old EMH from the Kostenki 14 site in Russia.
Link
January 01, 2010
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