Jamshid J. Tehrani

Human niche construction in interdisciplinary focus

Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance, comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally potent because it includes the social transmission and inheritance of cultural knowledge, and material culture. Human genetic inheritance in combination with human cultural inheritance thus provides a basis for gene–culture coevolution, and multivariate dynamics in cultural evolution. Niche construction theory potentially integrates the biological and social aspects of the human sciences. We elaborate on these processes, and provide brief introductions to each of the papers published in this theme issue.

Investigating cultural evolution through biological phylogenetic analyses of Turkmen textiles

The debate on the evolution of culture has focused on two processes in particular, phylogenesis and ethnogenesis. Recently, it has been suggested that the latter has probably always been more significant than the former. This proposal was assessed by applying cladistic methods of phylogenetic reconstruction to a data set comprising decorative characters from textiles produced by Turkmen tribes since the 18th century. The analyses focused on two periods in Turkmen history: the era in which most Turkmen practised nomadic pastoralism and were organised according to indigenous structures of affiliation and leadership; and the period following their defeat by Tsarist Russia in 1881, which is associated with the sedentarisation of nomadic Turkmen and their increasing dependence on the market. The results indicate that phylogenesis was the dominant process in the evolution of Turkmen carpet designs prior to the annexation of their territories, accounting for c.70% of the resemblances among the woven assemblages. The analyses also show that phylogenesis was the dominant process after 1881, although ethnogenesis accounted for an additional 10% of the resemblances among the assemblages. These results do not support the proposition that ethnogenesis has always been a more significant process in cultural evolution than phylogenesis.

Towards an archaeology of pedagogy : learning, teaching and the generation of material culture traditions

Abstract In this article we seek to build on efforts to apply the insights of social learning theory to interpret patterns of continuity and change in the archaeological record. This literature suggests that stable and often highly arbitrary material culture traditions are likely to be founded on our biologically evolved capacity for imitation. However, it has recently been argued that the latter may be insufficient to explain the long-term maintenance of complex and difficult-to-master skills, such as those required to produce stone tools, pots, textiles and other cognitively opaque cultural forms. To ensure that these skills are accurately transferred to the next generation, adults must actively guide and control the learning activities of their children, a mode of transmission that can be labelled ‘pedagogy’. The importance of pedagogy has often been overlooked in the theoretical and empirical literature on craft learning, a fact that can probably be attributed to an unnecessarily narrow conception of teaching that equates it with explicit linguistic instruction. Using ethnographic data gathered from detailed case studies, we characterize pedagogy in the context of craft apprenticeships as involving the gradual scaffolding of skill in a novice through demonstration, intervention and collaboration. Although these processes cannot be directly observed in the archaeological record, they can sometimes be inferred through the detailed reconstruction of operational chains in past technologies. The evidence we present suggests that pedagogy has played an essential role in securing the faithful transmission of skills across generations, and should be regarded as the central mechanism through which long-term and stable material culture traditions are propagated and maintained.

The Phylogeny of Little Red Riding Hood

Researchers have long been fascinated by the strong continuities evident in the oral traditions associated with different cultures. According to the ‘historic-geographic’ school, it is possible to classify similar tales into “international types” and trace them back to their original archetypes. However, critics argue that folktale traditions are fundamentally fluid, and that most international types are artificial constructs. Here, these issues are addressed using phylogenetic methods that were originally developed to reconstruct evolutionary relationships among biological species, and which have been recently applied to a range of cultural phenomena. The study focuses on one of the most debated international types in the literature: ATU 333, ‘Little Red Riding Hood’. A number of variants of ATU 333 have been recorded in European oral traditions, and it has been suggested that the group may include tales from other regions, including Africa and East Asia. However, in many of these cases, it is difficult to differentiate ATU 333 from another widespread international folktale, ATU 123, ‘The Wolf and the Kids’. To shed more light on these relationships, data on 58 folktales were analysed using cladistic, Bayesian and phylogenetic network-based methods. The results demonstrate that, contrary to the claims made by critics of the historic-geographic approach, it is possible to identify ATU 333 and ATU 123 as distinct international types. They further suggest that most of the African tales can be classified as variants of ATU 123, while the East Asian tales probably evolved by blending together elements of both ATU 333 and ATU 123. These findings demonstrate that phylogenetic methods provide a powerful set of tools for testing hypotheses about cross-cultural relationships among folktales, and point towards exciting new directions for research into the transmission and evolution of oral narratives.

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.

Comparative phylogenetic analyses uncover the ancient roots of Indo-European folktales

Ancient population expansions and dispersals often leave enduring signatures in the cultural traditions of their descendants, as well as in their genes and languages. The international folktale record has long been regarded as a rich context in which to explore these legacies. To date, investigations in this area have been complicated by a lack of historical data and the impact of more recent waves of diffusion. In this study, we introduce new methods for tackling these problems by applying comparative phylogenetic methods and autologistic modelling to analyse the relationships between folktales, population histories and geographical distances in Indo-European-speaking societies. We find strong correlations between the distributions of a number of folktales and phylogenetic, but not spatial, associations among populations that are consistent with vertical processes of cultural inheritance. Moreover, we show that these oral traditions probably originated long before the emergence of the literary record, and find evidence that one tale (‘The Smith and the Devil’) can be traced back to the Bronze Age. On a broader level, the kinds of stories told in ancestral societies can provide important insights into their culture, furnishing new perspectives on linguistic, genetic and archaeological reconstructions of human prehistory.

Kinship, Marriage, and the Genetics of Past Human Dispersals

Abstract The extent to which colonizing farmer populations have overwhelmed or “replaced” indigenous forager populations, as opposed to having intermarried with them, has been widely debated. Indigenous-colonist “admixture” is often represented in genetic models as a single parameter that, although parsimonious and simple, is incongruous with the sex-specific nature of mtDNA and Y-chromosome data. To help interpret genetic patterns, we can construct useful null hypotheses about the generalized migration history of females (mtDNA) as opposed to males (Y chromosome), which differ significantly in almost every ethnographically known society. We seek to integrate ethnographic knowledge into models that incorporate new social parameters for predicting geographic patterns in mtDNA and Y-chromosome distributions. We provide an example of a model simulation for the spread of agriculture in which this individual-scale evidence is used to refine the parameters.

Serial killers, spiders and cybersex : social and survival information bias in the transmission of urban legends

This study uses urban legends to examine the effects of the social information bias and survival information bias on cultural transmission across three phases of transmission: the choose-to-receive phase, the encode-and-retrieve phase, and the choose-to-transmit phase. In line with previous research into content biases, a linear transmission chain design with 60 participants aged 18-52 was used to examine the encode-and-retrieve phase, while participants were asked to rank their interest in reading the story behind a headline and passing a story on for the other two phases. Legends which contained social information (Social Type), legends which contained survival information (Survival Type), and legends which contained both forms of information (Combined Type) were all recalled with significantly greater accuracy than control material, while Social and Combined Type legends were recalled with significantly greater accuracy than Survival Type legends. In another study with 30 participants aged 18-22, no significant differences were found between legend types in either the choose-to-receive phase or the choose-to-transmit phase.

Expect the Unexpected? Testing for Minimally Counterintuitive (MCI) Bias in the Transmission of Contemporary Legends: A Computational Phylogenetic Approach

In this study, we use computational methods for analyzing cultural transmission to examine the role of cognitive selection pressures on the evolution of narratives, the first use of computational phylogenetic analysis in the study of contemporary legends. It has been suggested that a number of biases in transmission may alter the content and structure of narrative so as to maximize how transmittable it is. One bias that has attracted much attention is Boyer’s minimally counterintuitive (MCI) bias, which suggests that a cognitively optimal number of counterintuitive concepts increase the salience and, therefore, the transmission of a narrative. Previous research has used traditional folklore and religious texts to examine this bias and a cognitively optimum number of 1–2 or 2–3 counterintuitive concepts has been suggested. The present research uses the legend of “Bloody Mary,” a contemporary (or urban) legend with MCI elements in a computational phylogenetic analysis to examine the influence of MCI on cultural transmission and evolution. Counterintuitive and intuitive concepts were found to be equally stable in transmission, suggesting that MCI bias may function on the narrative as a whole, rather than individual concepts within it.

Patterns of Evolution in Iranian Tribal Textiles

Ever since the publication of The Origin of Species, anthropologists and archaeologists have been in turns enchanted and repulsed by the idea that cultural diversity can be explained by a Darwinian model of descent with modification. Over the last decade, this debate has intensified following the publication of a number of studies that have sought to reconstruct cultural histories using modern computational methods of phylogenetic analysis imported from biology. In this paper, I focus on evolution of tribal textile assemblages in Iran and Central Asia. Using cladistic phylogenetic analysis, I show that similarities and differences among the assemblages can be largely explained in terms of descent with modification from ancestral assemblages. Interestingly, the phylogenetic signal in design characters is just as strong (if not stronger) than the signal in technical characters. This may seem surprising given that techniques, like genes, are transmitted “vertically” from mothers to daughters whereas designs are frequently transmitted “horizontally” among peers. However, a closer examination reveals that the transmission of designs between weavers mainly occurs within, rather than between groups, and that, as in many cultures past and present, there are important constraints on the latter. This highlights that differences in the ways in which genes and cultural traits are transmitted among individuals should not be assumed to lead to differences in macro-level patterns of evolution, as many archaeologists and anthropologists have supposed.