TEMPORAL ORDERING OF SURFACE-COLLECTED OBSIDIAN ARTIFACTS BY HYDRATION MEASUREMENT

Two samples of obsidian projectile points from northwestern Nevada, one surface collected and the other excavated, were subjected to obsidian hydration measurement. The temporal ordering of the three projectile-point types in each of the two samples was demonstrated to be the same on the basis of their hydration measurements. The validity of this temporal ordering of the projectile-point types in the two samples was confirmed by the stratigraphic sequence of the types in the excavated sample. We have found that surface-collected obsidian artifacts can be relatively dated by hydration measurement. In northwestern Nevada they hydrate at a rate almost double that of their excavated typological counterparts, but their relative ordering remains the same.     

Flake scar patterns of Clovis points analyzed with a new digital morphometrics approach: evidence for direct transmission of technological knowledge across early North America

Clovis points are the principal diagnostic artifacts of a Clovis complex that spread across North America between ca. 11,050–10,800 radiocarbon years before present. Clovis may be the best documented Paleoamerican culture in North America, but much remains to be learned about the movement and interactions of Clovis peoples. Similarities among Clovis points from geographically diverse locations have led some researchers to suggest that a uniform projectile point technology existed across North America during Clovis times. Others have rejected this idea, proposing local and independent technological adaptations to different regional environments. To investigate these ideas, we used digital morphometrics to analyze 50 Clovis points from nine different contexts. First, 3D surface models of the points were created with a portable laser scanner. Next, these models were digitally cross-sectioned through both faces, yielding two-dimensional isoheight contours of flake scar patterns that reflect the original reduction techniques used to shape the projectile points. In the final step, the contours were transformed with elliptic Fourier analysis into Fourier coefficient series, and patterns of variation and symmetry were explored with principal components analysis. When compared to modern Clovis point replicas made by an expert knapper, the flake scar contours of the ancient Clovis points showed little morphological variation and a large degree of bifacial symmetry. Our results support the existence of a widespread standardized “Clovis” knapping technique, most likely transmitted through direct interaction between knappers from different groups.     

Variation in North American dart points and arrow points when one or both are present

The appearance of the bow and arrow in North America as a weapon-delivery system is predicted to have prompted an increase in variation among antecedent projectile points that tipped darts propelled by atlatls. Attributes of dart points are expected to display greater variation with the appearance of the bow as prehistoric artisans experimentally sought points that worked effectively as arrow points. Attributes of arrow points are predicted to also initially display much variation. Subsequent to the initial burst of variation, less-effective variants of attributes were winnowed out, causing a reduction in variation of attributes of both dart points and arrow points. Both coefficients of variation for individual attributes and summed coefficients of variation for multiple attributes of three sequences of projectile points from evolutionarily independent areas in North America confirm these predictions.     

Asphaltum hafting and projectile point durability: an experimental comparison of three hafting methods

The design of a projectile delivery system often plays a critical role in the durability and breakage patterns associated with spent projectile points. This paper presents the results of an experimental project designed to examine projectile point durability and breakage patterns between three different hafting methods. Specifically, we compare two asphaltum hafting techniques drawn from archaeological and ethnohistoric accounts from the Central Valley of California with a more stereotypical cross-hatched sinew hafting system. Our results suggest a small yet statistically significant increase in durability among asphaltum hafted points, opening the door to future research on these ethnohistorically documented hafting techniques.     

The origins of lithic projectile point technology: evidence from Africa,the Levant,and Europe

Projectile weaponry is a human cultural universal, but its origins and antiquity remain poorly understood. Stone- and bone-tipped projectile weapons have long been treated as emergent features of the "Upper Paleolithic" behavioral revolution. Recently it has been proposed that projectile technology was in widespread use among Homo sapiens populations in Africa during Middle Stone Age (MSA) times. One obstacle to researching the origins of projectile point technology is that the criteria archaeologists employ for recognizing plausible and implausible stone projectile points are largely subjective (overall tool shape, microwear traces). Tip cross-sectional area (TCSA) is a ballistically significant dimension that works well at discriminating North American stone projectile points (spearthrower dart tips and arrowheads) from spear points. This paper compares the TCSA values of ethnographic North American stone projectile points to hypothetical Middle and Upper Paleolithic stone projectile points from Africa, the Levant, and Europe. The results of this comparison do not support the hypothesis of widespread use of stone-tipped projectiles in Africa, the Levant, or Europe prior to 40 Ka. In the New World and in Australia, where we have the richest ethnographic record of stone projectile point use, these implements are largely employed in big-game hunting and in warfare. One or both of these factors may have played a role in the widespread adoption of stone projectile point technology after 40 Ka.     

Getting to the point: Evolutionary change in prehistoric weaponry

The evolution of prehistoric weaponry remains an open question in North American archaeology. The traditional model argues for an early use of the throwing spear followed by the spearthrower and bow and arrow. A major difficulty in testing this model is, identifying the functional variables that characterize different weaponry. The evolution of prehistoric weaponry is reexamined here from an evolutionary perspective where projectile points are considered part of the complete weapon system and variation within that system is identified. The engineering of four weapon systems, the thrusting spear, throwing spear, spearthrower, and bow, are examined to identify those point variables that enhance the success of the system. These variables are then measured on a 9000-year sequence of projectile points from northwestern Wyoming to examine time/space patterns. The patterns reveal that the spearthrower was in use prior to 7500 years ago.     

Shape matters: assessing regional variation of Bell Beaker projectile points in Central Europe using geometric morphometrics

Despite the large-scale expansion of Bell Beaker phenomenon, there is a tension between the normative Bell Beaker material culture categories and their local objectification in the form of real artefacts. Stone projectile points provide an opportunity to evaluate how much was the general category of such a point influenced by regional and local factors. The aim of this paper is to explore shape and size variation of Central European Bell Beaker projectile points from Moravia (Czech Republic) to elucidate factors responsible for this variation. The sample consists of 194 projectile points from 54 Central European Bell Beaker sites (2500–2300/2200 BC) distributed in Morava River catchment. The size and shape of projectile points were studied by landmark-based geometric morphometrics and expressed as shape groups, which have been assessed in terms of their spatial distribution, raw material, and reutilization. Although several shape categories of points were identified, there is a strong degree of uniformity in the research sample. The dominant shape category (75.4 % of points) was pervasive across geographic space and was not significantly affected either by raw material or reutilization. A lower degree of reutilization of points is interpreted as a consequence of a non-utilitarian role of projectile points, which represented a critical component of Bell Beaker mortuary practices.     

Experimental use and quantitative performance analysis of triangular flakes (Levallois points) used as arrowheads

The invention and widespread use of projectile weaponry is a characteristic presumed to exist only with Homo sapiens. However, as finds of wooden material during the early development of projectile weapons are extremely rare, this remains a contentious topic. Recent work has proposed a series of ballistically-significant morphological characteristics of stone points that yield information about their potential use. Here we report on initial experimental approaches to quantifying the performance of relatively simple stone points as arrow armatures. Two experimental trials were performed using a series of 51 Levallois points. The first, against a uniform density target, was designed to give an overall indication of performance. The second, against a simulated animal carcass, demonstrated the durability of these points. The results of this study suggest that small Levallois points could have functioned as arrowheads, albeit ones likely to break after limited use. They also suggest that these points’ penetrating power is strongly controlled by their morphometric characteristics, most notably their perimeter. This latter finding refines a method for assessing hypothetical Paleolithic stone points on the basis of tip cross-sectional area previously proposed by others.     

Cultural transmission, copying errors, and the generation of variation in material culture and the archaeological record

Archaeologists are adept at analyzing variation in artifacts. The discipline has well established and tested methods to track change through time and to evaluate the function of artifacts that depend upon measures of variation in the archaeological record. Although a critical concept, the means by which variation in material culture is generated is not well understood. This paper explores one source of variation, copying errors, and systematically examines how cultural transmission processes act to amplify, reduce, or maintain such variation. Using simple models, we generate expected distributions for the amount of variation that occurs through time under varying circumstances. This variation is caused by small errors that are transmitted from one person to another in the propagation and replication of cultural traits. These baseline values provide useful null models for explaining variation in prehistoric assemblages of artifacts. We use measurements of projectile points from Owens Valley and Woodland ceramics from Illinois to demonstrate the value of this approach.     

The diversity of North American projectile-point types,before and after the bow and arrow

Mimicking paleobiological studies of biodiversity, changes in the diversity of temporal types of North American projectile points are modeled to reveal evolutionary patterns of origination and extinction. Origination is modeled as rapid innovation of multiple point types (high diversity), and extinction is modeled as gradual winnowing of less-efficient types. Introduction of the bow and arrow as a new weapon-delivery system is modeled as an increase in point diversity. Six sequences of points (dart + arrow), six sequences of dart points, and six sequences of arrow points from western North America best match the model when the number of time periods ?5 and the number of types is >3.     

Investigating the peopling of North America through cladistic analyses of Early Paleoindian projectile points

The initial colonization of North America remains a controversial topic. There is widespread agreement that Clovis and related cultures of the Early Paleoindian period (∼11,500–10,500 BP) represent the first well-documented indications of human occupation, but considerable differences of opinion exist regarding the origins of these cultures. Here, we report the results of a study in which data from a continent-wide sample of Early Paleoindian projectile points were analyzed with cladistic methods in order to assess competing models of colonization as well as several alternative explanations for the variation among the points, including adaptation to local environmental circumstances, cultural diffusion, and site type effects. The analyses suggest that a rapidly migrating population produced the Early Paleoindian projectile point assemblages. They also suggest that the population in question is unlikely to have entered North America from either the Isthmus of Panama or the Midatlantic region. According to the analyses, the Early Paleoindians are more likely to have entered North America via either the ice-free corridor between the Laurentide and Cordilleran ice sheets that is hypothesized to have opened around 12,000 BP, or the Northwest Coast.     

Points and prey: a quantitative test of the hypothesis that prey size influences early Paleoindian projectile point form

Understanding the causes of variation within and between projectile point types is an important task for Paleoindian archaeologists since they rely heavily on points to investigate such things as settlement dynamics and hunting practices. One long-held explanation for the variation in early Paleoindian point form is that prey size influenced the size and shape of projectile points. The study reported here evaluated this hypothesis with standard and geometric morphometric data recorded on Clovis and Folsom points from the Southern Plains and Southwest that are associated with mammoth or bison remains. Points used to hunt mammoth were found to be larger and of a different shape than points used to hunt bison, which supports the hypothesis. However, when both point type and prey size were taken into account, the results ran counter to predictions. Potential explanations for this discrepancy are discussed.     

What Are Policy Punctuations? Large Changes in the Legislative Agenda of the UK Government, 1911–2008

In this article, we argue that policy punctuations differ from each other in ways that reflect distinct types of political change. We identify three main kinds. The first are procedural changes that have unique unrelated policies within the same issue area. Within the remaining large policy changes, high‐salience punctuations are associated with increased attention in the media, whereas low‐salience punctuations do not attract such scrutiny. The analysis applies the typology to data from the UK Policy Agendas Project, identifying punctuations from the content of Acts of the UK Parliament between 1911 and 2008. Using evidence from the historical record and the data series, the analysis places each observation within the typology. We claim that the typology has a more general application and could be replicated in other jurisdictions and time periods. We conclude that attention to the historical record and qualitative studies of punctuations can complement and inform the analysis of aggregate data series.     

Prehistoric hunters and gatherers of Brazil

Although carbon-14 dates prior to 13,000 B.P. have been obtained from several sites east and south of Amazonia, their reliability is uncertain. By about 11,000 B.P., however, two lithic traditions were widespread. The Uruguai tradition, characterized by bifacial stemmed projectile points, was associated with open vegetation in the south; the Itaparica tradition, emphasizing well-formed unifacial artifacts, had dispersed over the eastern tropical parklands. An enormous amount and variety of rock paintings and/or engravings are associated with the latter. Around 7000 B.P., two new traditions emerged to exploit new habitats. The Humaitá tradition, characterized by large bifacial tools and an absence of stone projectile points, expanded over the broad-leaved forests in the south, leaving the open landscapes dominated by the projectile point-using Umbu tradition. The sambaqui (shell midden) tradition, also emphasizing large bifaces, developed along rugged portions of the southern coast. By 4000 B.P., groups along the coast of Rio de Janeiro and Espírito Santo were using domesticated or semidomesticated plants, perhaps sweet manioc. Maize was being grown in Minas Gerais by about 3500 B.P. Carbon-14 dates from numerous sites indicate, however, that the hunter-gatherer way of life persisted in many places long after the advent of pottery-making horticulturalists. The existence of large temporal and spatial gaps even in regions with considerable investigation makes it difficult to reconstruct the process of evolution reflected in these archaeological complexes. Correlations between cultural traditions and environmental fluctuations indicate, however, that adaptation to changing conditions was a significant challenge faced by prehistoric Brazilian populations.     

Hunting lesions caused by osseous projectile points: experimental results and archaeological implications

The identification of projectile impact traces on archaeological faunal remains is an important issue for understanding prehistoric hunting behavior, especially in the Paleolithic and Mesolithic. From the beginning of the Upper Paleolithic in Europe, and earlier in Africa, projectiles tipped with osseous points were of great importance for subsistence; but thus far, no specific experimental reference has been developed to help identify the traces left by these points. In 2003 and 2004 two series of projectile experiments with antler points of Magdalenian design were organized, involving two ox calves and two female fallow deer as targets for bow and spearthrower shooting. The subsequent study demonstrates that positive identifications of impact traces left by osseous points can be made. The observation of 127 impact traces allowed us to distinguish three main types of traces: notches, punctures and perforations. The relationships between the nature of the impact traces and the (i) target species, (ii) characteristics of the impacted bones, and (iii) type of weapon are presented. Synthesized results are then discussed within the context of the European Upper Paleolithic and Mesolithic.     

Projectile points,people, and Plains Paleoindian perambulations

Archaeologists generally agree that Paleoindian residential groups moved regularly over extremely large ranges. However, on the Great Plains, this argument depends substantially on datasets derived largely or entirely from projectile points rather than from systematic analysis of a wide range of artifacts. This paper argues that projectile points differ from most Paleoindian tools in ways that make such datasets unlikely to be reliable sources of information on range sizes. Furthermore, evidence from Paleoindian tool caches and the condition of discarded points suggest strongly that the raw material used to produce projectile points at least sometimes moved across the Plains independently of material used to make most other kinds of flaked stone tools. This, in turn, implies that not all stone used during Paleoindian times was procured by visits of whole residential groups to raw material sources, raising serious questions about the validity of widespread views of Paleoindian mobility.     

Evaluating indices of curation for Archaic North American bifacial projectile points

Abstract

This paper addresses the definitions of the term “curation” and the utility of various techniques for its quantification based on morphometric, isometric, and geometric characteristics of bifacial projectile points. The definitions were evaluated through the comparative application of curation indices to a collection of Archaic projectile points from the Southwestern United States. Bifacial projectile points from the Walt Jones Farm site (10Br9), Georgia, were analyzed with the accompanying debitage using curation indices and non-indexical measures. Comparisons of the curation indices with non-indexical measures allow an examination of the utility of the term “curation,” and we argue that indices of curation cannot operate in a vacuum without additional information concerning an assemblage.     

Duration Modeling of Spatial Point Patterns

This paper attempts to further the research by Odland and Ellis (1992) in applying event history methodology to the analysis of spatial point patterns (that is, event patterns). Its empirical focus is the event pattern derived from the adoption of an agricultural innovation, the Harvestore, in southern Ontario, Canada, from 1963 to 1986. Event history analysis involves the use of discrete-state, continuous-time stochastic models to investigate a temporal longitudinal record on discrete variables. Event history models are usually concerned with durations of time between events and the effects of intertemporal time dependencies on future event occurrences. As such, they are often referred to as duration models. Many of the methods used in event history analysis allow the use of other nonnegative interval measurements in place of standard temporal intervals to investigate a series of events. In particular, spatial intervals (or durations) of distances between events may also be accommodated by event history models. Our analysis extends the previous research of Odland and Ellis (1992) by using a wider range of parametric models to explore duration dependence, investigating the role of spatial censoring, and using a more extensive set of explanatory variables. In addition, simulation experiments and graphical tests are used to evaluate the empirical event pattern against one generated from Complete Spatial Randomness. Results indicate that the event pattern formed by the Harvestore adopter farms is clustered (that is, is described by positive duration dependency), the sales agent is a significant factor in the distribution of adopters, and that contrasting results are obtained from the analysis using censored data versus uncensored data.     

从“象鼻盉”到原始瓷大口折肩尊——论夏商时期东南地区对中原王朝的一种贡赋模式

本文利用类型学与文化因素分析方法,试析夏商时期在中国南北方广泛分布,并具有极高社会价值的两类陶瓷器——"象鼻盉"及原始瓷大口折肩尊,通过寻找二者在创烧与文化交流背景下的相同点,进而分析中原地区、长江中游地区以及东南地区在这一时期的一种文化交流模式——贡赋。