Testing for divergent transmission histories among cultural characters: a study using Bayesian phylogenetic methods and Iranian tribal textile data

Background

Archaeologists and anthropologists have long recognized that different cultural complexes may have distinct descent histories, but they have lacked analytical techniques capable of easily identifying such incongruence. Here, we show how Bayesian phylogenetic analysis can be used to identify incongruent cultural histories. We employ the approach to investigate Iranian tribal textile traditions.

Methods

We used Bayes factor comparisons in a phylogenetic framework to test two models of cultural evolution: the hierarchically integrated system hypothesis and the multiple coherent units hypothesis. In the hierarchically integrated system hypothesis, a core tradition of characters evolves through descent with modification and characters peripheral to the core are exchanged among contemporaneous populations. In the multiple coherent units hypothesis, a core tradition does not exist. Rather, there are several cultural units consisting of sets of characters that have different histories of descent.

Results

For the Iranian textiles, the Bayesian phylogenetic analyses supported the multiple coherent units hypothesis over the hierarchically integrated system hypothesis. Our analyses suggest that pile-weave designs represent a distinct cultural unit that has a different phylogenetic history compared to other textile characters.

Conclusions

The results from the Iranian textiles are consistent with the available ethnographic evidence, which suggests that the commercial rug market has influenced pile-rug designs but not the techniques or designs incorporated in the other textiles produced by the tribes. We anticipate that Bayesian phylogenetic tests for inferring cultural units will be of great value for researchers interested in studying the evolution of cultural traits including language, behavior, and material culture.     

On the comparison of population-level estimates of haplotype and nucleotide diversity: a case study using the gene cox1 in animals

Estimates of genetic diversity represent a valuable resource for biodiversity assessments and are increasingly used to guide conservation and management programs. The most commonly reported estimates of DNA sequence diversity in animal populations are haplotype diversity (h) and nucleotide diversity (π) for the mitochondrial gene cytochrome c oxidase subunit I (cox1). However, several issues relevant to the comparison of h and π within and between studies remain to be assessed. We used population-level cox1 data from peer-reviewed publications to quantify the extent to which data sets can be re-assembled, to provide a standardized summary of h and π estimates, to explore the relationship between these metrics and to assess their sensitivity to under-sampling. Only 19 out of 42 selected publications had archived data that could be unambiguously re-assembled; this comprised 127 population-level data sets (n ≥ 15) from 23 animal species. Estimates of h and π were calculated using a 456-base region of cox1 that was common to all the data sets (median h=0.70130, median π=0.00356). Non-linear regression methods and Bayesian information criterion analysis revealed that the most parsimonious model describing the relationship between the estimates of h and π was π=0.0081 h(2). Deviations from this model can be used to detect outliers due to biological processes or methodological issues. Subsampling analyses indicated that samples of n>5 were sufficient to discriminate extremes of high from low population-level cox1 diversity, but samples of n ≥ 25 are recommended for greater accuracy.     

An investigation of the relationship between innovation and cultural diversity

In this paper we apply reaction-diffusion models to explore the relationship between the rate of behavioural innovation and the level of cultural diversity. We investigate how both independent invention and the modification and refinement of established innovations impact on cultural dynamics and diversity. Further, we analyse these relationships in the presence of biases in cultural learning and find that the introduction of new variants typically increases cultural diversity substantially in the short term, but may decrease long-term diversity. Independent invention generally supports higher levels of cultural diversity than refinement. Repeated patterns of innovation through refinement generate characteristic oscillating trends in diversity, with increasing trends towards greater average diversity observed for medium but not low innovation rates. Conformity weakens the relationship between innovation and diversity. The level of cultural diversity, and pattern of temporal dynamics, potentially provide clues as to the underlying process, which can be used to interpret empirical data.     

Microsporidian life cycles and diversity: the relationship between virulence and transmission

The microsporidia are obligate intracellular parasites which have diverse life cycles involving both horizontal and vertical transmission and parasitise a wide range of vertebrate and invertebrate hosts. In this paper we consider the life cycles and diversity of the microsporidia. We focus in particular on the relationship between parasite transmission and virulence and its implications for host-parasite coevolution. The use of horizontal and vertical routes of transmission varies between species and there is a strong link between transmission and virulence. Horizontal transmission is characterised by a high parasite burden and associated pathogenicity. In contrast, vertical transmission is characterised by low virulence, which has led to under-reporting of this important transmission route. Vertically transmitted microsporidia may also cause male killing or feminisation of their host, with implications for host population sex ratio and stability. Phylogenetic analysis shows that vertical transmission occurs in diverse branches of the Microspora. We find that there is evidence for vertical transmission in both vertebrate and invertebrate hosts and conclude that it is a common or possibly even ubiquitous transmission route within this phylum.     

Macro-evolutionary studies of cultural diversity: a review of empirical studies of cultural transmission and cultural adaptation

A growing body of theoretical and empirical research has examined cultural transmission and adaptive cultural behaviour at the individual, within-group level. However, relatively few studies have tried to examine proximate transmission or test ultimate adaptive hypotheses about behavioural or cultural diversity at a between-societies macro-level. In both the history of anthropology and in present-day work, a common approach to examining adaptive behaviour at the macro-level has been through correlating various cultural traits with features of ecology. We discuss some difficulties with simple ecological associations, and then review cultural phylogenetic studies that have attempted to go beyond correlations to understand the underlying cultural evolutionary processes. We conclude with an example of a phylogenetically controlled approach to understanding proximate transmission pathways in Austronesian cultural diversity.     

The cophylogeny of populations and cultures: reconstructing the evolution of Iranian tribal craft traditions using trees and jungles

Phylogenetic approaches to culture have shed new light on the role played by population dispersals in the spread and diversification of cultural traditions. However, the fact that cultural inheritance is based on separate mechanisms from genetic inheritance means that socially transmitted traditions have the potential to diverge from population histories. Here, we suggest that associations between these two systems can be reconstructed using techniques developed to study cospeciation between hosts and parasites and related problems in biology. Relationships among the latter are patterned by four main processes: co-divergence, intra-host speciation (duplication), intra-host extinction (sorting) and horizontal transfers. We show that patterns of cultural inheritance are structured by analogous processes, and then demonstrate the applicability of the host-parasite model to culture using empirical data on Iranian tribal populations.     

沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓( Bryum argenteum Hedw.)的遗传多样性进行了研究。结果显示:岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度( G st = 0. 453)大于内陆居群( G st = 0. 387),岛屿居群的遗传分化与地理来源间存在极显著相关性( r = 0. 478, n = 175, P < 0. 001)。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29. 4%~ 29. 7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。     

沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓（Bryum argenteum Hedw.）的遗传多样性进行了研究。结果显示：岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度（G_st=0.453）大于内陆居群（G_st=0.387）,岛屿居群的遗传分化与地理来源间存在极显著相关性（r=0.478,n=175,P<0.001）。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29.4%~29.7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。     

广西南丹县生物多样性和文化多样性与生态旅游的关系

南丹县地处广西西北边陲 ,与贵州接壤 ,为多民族聚居地 ,是大西南出海铁路和高速公路通道的咽喉要地。全县总面积 3916ｋｍ2 ,人口 2 7.6万 ,全国第二大水电站———龙滩水电站距县城 76ｋｍ ,是一个具有交通枢纽和商贸物资集散功能的地方。矿产资源丰富 ,目前已查明的有锡、锑、铅、铜、银和铟等 2 0多种有色金属 ,储量超过 10 0 0× 10 4 ｔ,是罕见的富矿区 ,有“有色金属之乡”之称。其中 ,锡的储量 144× 10 4 ｔ,随着云南固旧锡都的衰落 ,南丹县将成为中国新的锡都。该县农业资源也很丰富 ,有许多著名的土特产品 ,例如黄蜡李、瑶鸡、魔…     

Molecular genetic diversity in populations of the stingless bee Plebeia remota: A case study

Genetic diversity is a major component of the biological diversity of an ecosystem. The survival of a population may be seriously threatened if its genetic diversity values are low. In this work, we measured the genetic diversity of the stingless bee Plebeia remota based on molecular data obtained by analyzing 15 microsatellite loci and sequencing two mitochondrial genes. Population structure and genetic diversity differed depending on the molecular marker analyzed: microsatellites showed low population structure and moderate to high genetic diversity, while mitochondrial DNA (mtDNA) showed high population structure and low diversity in three populations. Queen philopatry and male dispersal behavior are discussed as the main reasons for these findings.     

Evidence for regional diversity and host adaptation in Iranian populations of the Russian wheat aphid

Effective pest management is greatly facilitated by knowledge of the genetic structure and host adaptation of the pest species in question. The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko) (Homoptera: Aphididae: Macrosiphini), is an important economic pest in many cereal‐growing areas of the world, and in this study we investigated these aspects of its populations, using microsatellite markers and host plant response assays. Diuraphis noxia was sampled from 38 locations in Iran and genotyped at four polymorphic microsatellite loci that had been isolated from various Sitobion species. We identified 50 multilocus genotypes in 376 individuals. The overall observed heterozygosity was 0.134. F‐statistics showed a regional partitioning in D. noxia populations with overall F_ST = 0.231. In addition, there was a significant correlation between genetic and geographic distances. In order to test for the ecological consequences of genetic variability in D. noxia, biotypic variation amongst the isolates collected from wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) was evaluated on a number of resistant and susceptible wheat varieties. The plant variables we measured were damage rating (based on leaf chlorosis, leaf rolling, wilting, and death of the host plant), host plant dry weight, and root length. Damage rating was the best criterion for detecting biotypic variation in D. noxia. Discriminant analysis correctly classified the isolates in respective groups in 80–91.8% of the cases. The barley isolate showed no differences in performance on resistant and susceptible wheat, indicating a lack of gene‐by‐gene relationship with wheat plants. In contrast, wheat isolates differentially damaged the resistant and susceptible plants and showed moderate to severe virulence.     

Cumulative cultural dynamics and the coevolution of cultural innovation and transmission: an ESS model for panmictic and structured populations

When individuals in a population can acquire traits through learning, each individual may express a certain number of distinct cultural traits. These traits may have been either invented by the individual himself or acquired from others in the population. Here, we develop a game theoretic model for the accumulation of cultural traits through individual and social learning. We explore how the rates of innovation, decay, and transmission of cultural traits affect the evolutionary stable (ES) levels of individual and social learning and the number of cultural traits expressed by an individual when cultural dynamics are at a steady‐state. We explore the evolution of these phenotypes in both panmictic and structured population settings. Our results suggest that in panmictic populations, the ES level of learning and number of traits tend to be independent of the social transmission rate of cultural traits and is mainly affected by the innovation and decay rates. By contrast, in structured populations, where interactions occur between relatives, the ES level of learning and the number of traits per individual can be increased (relative to the panmictic case) and may then markedly depend on the transmission rate of cultural traits. This suggests that kin selection may be one additional solution to Rogers's paradox of nonadaptive culture.     

Women and the Iranian Revolution: A village case study

Conclusion All in all, the activism of the Aliabad seyyid women in the Iranian Revolution followed the lines of traditional concerns, traditional methods, and traditional constraints on the activities of women. Women hoped for improved justice, safety for their families, and restoration of a semblance of peace in the village and the nation as a whole. Women's political methods were those of social interaction and use of their verbal abilities, emotional displays, and physical presence to show support. They followed the usual constraints on their behavior by marching in the company of their usual network of companions, separate from men and covered with their chadors, and did not neglect their families and households.The two changes were in the level of political involvement: national rather than local level, and the locus of political activity—Shiraz rather than the village of Aliabad. The local level of political activity was no longer the level at which policy and forces determined the safety and welfare of their family and relatives. With the Shah's centralization program, power over the lives of villagers lay at higher levels. With the merging of local level politics and national level politics during the incidents of violence on December 7 and 8, 1978, women began to realize that the target of their political activism must also be at higher levels. In hopes of having some effect on national level politics and thereby on the safety and welfare of their family members, the Aliabad seyyid women traveled into Shiraz to demonstrate in the revolutionary movement

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On the relationship between sample plot size and beta diversity in boreal coniferous forests

Nested sample plots of three sizes (16, 1, and 1/16 sq. m) from three different studies of Norwegian coniferous forests have been subjected to DCA ordination using the same choice of options. At each sample plot size, species quantities are recorded as frequency in 16 subplots. Beta diversity, measured as length of the first DCA axis, invariably increased upon lowering of sample plot size. The same applied to the eigenvalues of the axes. This is explained as a consequence of the weakening of structure in the data matrices when the fine-grained patterns of the vegetation are emphasized.     

Quantifying cultural macro-evolution: a case study of the hinoeuma fertility drop

Understanding patterns and underlying processes of human cultural diversity has been a major challenge in evolutionary anthropology. Recent developments in the study of cultural macro-evolution have illuminated various novel aspects of cultural phenomena at the population level. However, limitations in data availability have constrained previous analyses to use simplest models ignoring factors that potentially affect cultural evolutionary dynamics. Here, we focus on two such factors: accumulated effects of cultural transmission between populations over time and variation in social influence among populations. As a test case, we analyze data on the hinoeuma fertility drop, the Japanese nation-wide drastic decline in the number of births caused by a culturally-transmitted superstition recurring every sixty years, to show that these factors do play significant roles. Specifically, our results suggest that transmission of the superstition in a short timescale has tended to occur among neighboring populations, while transmission in a long timescale is likely to have occurred between populations culturally close to each other, with the cultural closeness being measured by similarity in dialects. The results also indicate a special role played by a population occupying a center in a language–distance network (the cultural center) in the spread of the superstition.     

水松自然种群和人工种群遗传多样性比较

采用ISSR分子标记技术分析水松不同起源种群的遗传多样性.结果表明:10条引物共检测出95个扩增位点,多态位点数占39.0%.与其他濒危裸子植物相比,水松的遗传多样性较低,遗传分化系数Gst为0.3982,基因流Nm仅0.3778,种群间存在一定程度的遗传分化,但种群内变异占主导地位;遗传距离与地理距离呈正相关关系.自然种群的多态位点百分率(P)、Nei的条带多样度(He)和Shannon信息指数(Ⅰ)平均值(39.3%、0.1499和0.2202)分别高于人工种群(30.7%、0.1265和0.1759).自然种群的遗传分化系数(Gst0.4513)和平均遗传距离(D=0.0301)也高于人工种群(Gst=0.3025,D=0.0192).     

On the relationship between plant species diversity and genetic diversity of Plantago lanceolata (Plantaginaceae) within and between grassland communities

Aims and Methods The relationship between genetic diversity and species diversity and the underlying mechanisms are of both fundamental and applied interest. We used amplified fragment length polymorphism (AFLP) and vegetation records to investigate the association between genetic diversity of Plantago lanceolata and plant species diversity using 15 grassland communities in central Germany. We used correlation and partial correlation analyses to examine whether relationships between genetic and species diversity were direct or mediated by environmental differences between habitats.Important findings Both within- and between-population genetic diversity of P. lanceolata were significantly positively correlated with plant species diversity within and between sites. Simple and partial correlations revealed that the positive correlations indirectly resulted from the effects of abiotic habitat characteristics on plant species diversity and, via abundance, on genetic diversity of P. lanceolata. Thus, they did not reflect a direct causal relationship between plant species diversity and genetic diversity of P. lanceolata, as would have been expected based on the hypothesis of a positive relationship between plant species diversity and niche diversity.     

On the relationship between phyllotaxy and vasculature: a synthesis

There is a definite relationship between the phyllotactic fraction and the sympodia uniting median leaf traces in a stem. The denominator of the phyllotactic fraction is the number of sympodia in the stem, and the numerator is the number of sympodia counted in passing from the sympodium of one leaf to that of an adjacent leaf on the genetic helix. This relationship holds for species with closed as well as open vascular systems. Of the 100 shoots (93 species) whose vasculature has been reviewed from the literature only one shows no apparent relationship between the phyllotactic fraction and the vasculature. Shoots for 87 species show the relationship described above while shoots of five species have both irregular phyllotaxis and vasculature. The mathematical constraints on this relationship are shown to depend on the divergence angle and the fact that sympodia do not cross one another. That there are biological controls on this relationship in addition to the purely mathematical ones is shown by the fact that sympodial connections are almost universally made along orthostichies. These controls most likely operate on factors that influence the formation of orthostichies such as the relationship between leaf-shape and size of the apical dome.