The revolution that wasn't: a new interpretation of the origin of modern human behavior.

Not by Genes Alone: How Culture Transformed Human Evolution

Many ``real-world'' networks are clearly defined while most ``social'' networks are to some extent subjective. Indeed, the accuracy of empirically-determined social networks is a question of some concern because individuals may have distinct perceptions of what constitutes a social link. One unambiguous type of connection is sexual contact. Here we analyze data on the sexual behavior of a random sample of individuals, and find that the cumulative distributions of the number of sexual partners during the twelve months prior to the survey decays as a power law with similar exponents $\alpha \approx 2.4$ for females and males. The scale-free nature of the web of human sexual contacts suggests that strategic interventions aimed at preventing the spread of sexually-transmitted diseases may be the most efficient approach.

The Web of Human Sexual Contacts

We generated genome-wide data from 69 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of almost 400,000 polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of Western and Far Eastern Europe followed opposite trajectories between 8,000-5,000 years ago. At the beginning of the Neolithic period in Europe, ∼8,000-7,000 years ago, closely related groups of early farmers appeared in Germany, Hungary and Spain, different from indigenous hunter-gatherers, whereas Russia was inhabited by a distinctive population of hunter-gatherers with high affinity to a ∼24,000-year-old Siberian. By ∼6,000-5,000 years ago, farmers throughout much of Europe had more hunter-gatherer ancestry than their predecessors, but in Russia, the Yamnaya steppe herders of this time were descended not only from the preceding eastern European hunter-gatherers, but also from a population of Near Eastern ancestry. Western and Eastern Europe came into contact ∼4,500 years ago, as the Late Neolithic Corded Ware people from Germany traced ∼75% of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least ∼3,000 years ago, and is ubiquitous in present-day Europeans. These results provide support for a steppe origin of at least some of the Indo-European languages of Europe.

Massive migration from the steppe was a source for Indo-European languages in Europe

This article evaluates theories of the origins of sex differences in human behavior. It reviews the cross-cultural evidence on the behavior of women and men in nonindustrial societies, especially the activities that contribute to the sex-typed division of labor and patriarchy. To explain the cross-cultural findings, the authors consider social constructionism, evolutionary psychology, and their own biosocial theory. Supporting the biosocial analysis, sex differences derive from the interaction between the physical specialization of the sexes, especially female reproductive capacity, and the economic and social structural aspects of societies. This biosocial approach treats the psychological attributes of women and men as emergent given the evolved characteristics of the sexes, their developmental experiences, and their situated activity in society.

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A cross-cultural analysis of the behavior of women and men: implications for the origins of sex differences.

Les problemes poses par l'analyse de ce site concernent sa chronologie. Pour arriver a leurs fins, les AA. ont combine differentes methodes ou le radiocarbone et les statistiques tiennent une grande part car combines entre eux

A case study in combining radiocarbon and archaeological information: the early Bronze Age settlement of St. Veit-Klinglberg, Land Salzburg, Austria

graphic data rather than archaeological evidence (e.g. Kirch & Green 1987; Durham 1992; Welsch et al. 1992; Mace & Pagel 1994; Moore 1994a,b; Moore & Romney 1994; Guglielmino et al. 1995; Holden & Mace 1999). How can we assess the relative contribution of phylogenesis and ethnogenesis to the patterns in the archaeological record? In this chapter, we argue that this archaeological problem is related to problems that have been successfully confronted by biologists, linguists and stemmatists. We then present a case study, in which we use a technique that was developed to tackle the aforementioned biological problem to assess the roles of phylogenesis and ethnogenesis in producing the patterns of variation in a group of pottery assemblages from the Central European Neolithic. Lastly, we consider the implications of our findings for current archaeological approaches to evidence for culture change.

Processes of culture change in prehistory: a case study from the European Neolithic

Cultural change can be quantified by temporal changes in frequency of different cultural artefacts and it is a central question to identify what underlying cultural transmission processes could have caused the observed frequency changes. Observed changes, however, often describe the dynamics in samples of the population of artefacts, whereas transmission processes act on the whole population. Here we develop a modelling framework aimed at addressing this inference problem. To do so, we firstly generate population structures from which the observed sample could have been drawn randomly and then determine theoretical samples at a later time t2 produced under the assumption that changes in frequencies are caused by a specific transmission process. Thereby we also account for the potential effect of time-averaging processes in the generation of the observed sample. Subsequent statistical comparisons (e.g. using Bayesian inference) of the theoretical and observed samples at t2 can establish which processes could have produced the observed frequency data. In this way, we infer underlying transmission processes directly from available data without any equilibrium assumption. We apply this framework to a dataset describing pottery from settlements of some of the first farmers in Europe (the LBK culture) and conclude that the observed frequency dynamic of different types of decorated pottery is consistent with age-dependent selection, a preference for 'young' pottery types which is potentially indicative of fashion trends.

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A generative inference framework for analysing patterns of cultural change in sparse population data with evidence for fashion trends in LBK culture

To our knowledge, the dataset described in this paper represents the largest existing repository of archaeological settlement (7,383 sites) and radiocarbon data (816 samples) for central Italy, spanning the period from the Late Mesolithic (ca. 8,000 BC) to the fall of the Roman Empire (500 AD). This dataset is also one of the six case studies in a Leverhulme Trust funded project called Changing the Face of the Mediterranean: Land Cover and Population Since the Advent of Farming (Grant Ref. RPG-2015-031), a Plymouth-UCL collaboration which aims to reconstruct regional demographic trends and change in land cover/vegetation over the longue duree.

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Stephen Shennan

Papers

A case study in combining radiocarbon and archaeological information: the early Bronze Age settlement of St. Veit-Klinglberg, Land Salzburg, Austria

Processes of culture change in prehistory: a case study from the European Neolithic

A generative inference framework for analysing patterns of cultural change in sparse population data with evidence for fashion trends in LBK culture

Regional Demographic Trends and Settlement Patterns in Central Italy: Archaeological Sites and Radiocarbon Dates

Style, Interaction and Demography among the Earliest Farmers of Central Europe