Reaping ‘rewards’ in sickle use-wear analysis

Recently in their research Goodale et al. (2010) as well as that of Vardi et al. (2010) independently tackled issues of effectively measuring attrition/gloss rates on sickle blade tools from Southwest Asia. Interestingly, while applying new methodology to analyzing sickle tools from different cultural and temporal contexts, these two papers arrived at a similar conclusion: sickle tools were likely very expensive to make, and thus, considerations were made during their production to ensure long use-lives to benefit the people who made and used them in prehistory. Stemp et al. (in this issue) provide a methodological critique of both studies. In addressing their critique we make several points. First it is important to note that Stemp et al. provide no new experimental analysis to justify their assertions, and their critique is ultimately, at best, guesswork. Second, the minimal reanalysis of the data Stemp et al. do conduct arguably lead to the same preliminary conclusion at which we originally arrived: the prehistoric sickle blades we examined were used longer than those we replicated. As stated in our original paper, lithic use-wear studies often do not address issue of reliable and reproducible methods. We believe that our original study helps fill this missing component, and that measuring edge thickness is much less subjective than conventional features on stone tools traditionally identified microscopically. From our perspective, Stemp et al. present largely unsupported critical commentary, lacking substantial reanalysis or experiments to complement or justify their commentary. In the end Stemp et al. provide little more than interesting ideas and conjecture.     

Reaping the rewards: the potential of well designed methodology,a comment on Vardi et al. (Journal of Archaeological Science 37 (2010) 1716–1724) and Goodale et al. (Journal of Archaeological Science 37 (2010) 1192–1201)

The recent articles by Vardi et al., “Tracing sickle blade levels of wear and discard patterns: a new sickle gloss quantification method” (Journal of Archaeological Science 37 (2010) 1716–1724), and Goodale et al., “Sickle blade life-history and the transition to agriculture: an early Neolithic case study from Southwest Asia” (Journal of Archaeological Science 37 (2010) 1192–1201), are two papers that seek to address interesting archaeological questions through the development of new approaches to measuring the duration of stone tool use. Here comment is made on the fashion in which research design and analytic procedures contribute to limit the capabilities of each of the techniques presented. Whilst the authors support the investigation of novel techniques, in order for the results of any use-wear analysis to be accepted as reliable the methods employed must be demonstrably sound.     

Tracing sickle blade levels of wear and discard patterns: a new sickle gloss quantification method

Although sickle blades gloss is known to form during the harvest, which is a dynamic process and although it is known to be a type of wear which is the outcome of the repetitive encounters between the sickle blades working edges and plant stems; there is no common way to quantify its intensity. Since there is no consensus over a specific scale that will enable the estimation of the amount of wear, based on the quantification of gloss brightness intensity. In this paper we propose a new measurement system which is based on the projection of laser (He–Ne) beam on glossed sickle blades and an analysis of the reflected images. The results form a relative scale from which it is possible to infer on the sickle blades level of wear, and to create discard models.     

A comment on Steele’s (2010) “radiocarbon dates as data: quantitative strategies for estimating colonization front speeds and event densities”

We show that Steele’s (2010) criticisms of Hamilton and Buchanan (2007) and Buchanan et al. (2008) do not hold water and demonstrate that his re-analyses of Hamilton and Buchanan’s (2007) and Buchanan et al'.s (2008) datasets are flawed. In the process, we highlight some important issues for researchers interested in using radiocarbon dates to reconstruct population movements and demography. Most notably, we explain why OLS regression is preferable to RMA regression when estimating diffusion velocity, and demonstrate that the summed probability distributions yielded by CalPal are more reliable as guides to past demographic change than those produced by Calib and OxCal.     

A spatial interaction model of vote dispersion

How do votes disperse through a territory? Studies of spatial voting patterns have largely focused on the influence of local factors on voting. The “Friends and Neighbors” model (Key (1949)) explains the advantage of candidates running for office in the locality with which they are associated (Arzheimer and Evans (2012, 2014): Collignon and Sajuria (2018); Horiuchi et al. (2018); Jankowski (2016); Hunt (2020); Munis (2021)), and the “neighbor” effect helps to explain why votes spread. More recent studies have found that the dispersion of votes decreases with distance (Put et al. (2020); Arzheimer and Evans (2012)). However, we know little about how spatial patterns of voting emerge or the mechanism behind the neighbor effect. We argue that this effect depends on the neighbors’ access to information about a candidate, which is constrained by the way information flows. Although scholars have argued that information is a relevant driver explaining the dispersion of votes (Bowler et al. (1993); Arzheimer and Evans (2012); Evans et al. (2017); Campbell, Cowley, Vivyan, and Wagner (2019)), no research has examined the relevance of the network through which information flows. We propose that a spatial interaction model (Wilson (1971)) allows us to predict where this information flows or the voting pattern that will form. Taking advantage of a quasi-natural experiment in Brazilian legislative elections in 1974 and 1978, we show that votes spread through areas of influence created by a hierarchy of cities based on the flows of exchanges among them, including information. We then use our spatial interaction model to predict voting patterns in the elections of 1978 using data from the 1974 elections. Our findings show that the spatial interaction model results fit the data quite well and can help predict spatial patterns of voting.     

OSL and TL dating of the Middle Stone Age sequence at Diepkloof Rock Shelter (South Africa): a clarification

Diepkloof Rock Shelter offers an exceptional opportunity to study the onset and evolution of both Still Bay (SB) and Howiesons Poort (HP) techno-complexes. However, previous age estimates based on luminescence dating of burnt quartzites (Tribolo et al., 2009) and of sediments (Jacobs et al., 2008) were not in agreement. Here, we present new luminescence ages for 17 rock samples (equivalent dose estimated with a SAR-ITL protocol instead of classical MAAD-TL) as well as for 5 sediment samples (equivalent dose estimated with SAR-single grain OSL protocol) and an update of the 22 previous age estimates for burnt lithics (modified calibration and beta dose estimates). While a good agreement between the rock and sediment ages is obtained, these estimates are still significantly older than those reported by Jacobs et al. (2008). After our own analyses of the sediment from Diepkloof, it is suspected that these authors did not correctly chose the parameters for the equivalent dose determination, leading to an underestimate of the equivalent doses, and thus of the ages.     

‘True British sailors’: a comment on the origin of the men of the Mary Rose

Bell et al. (2009) have recently published an isotopic investigation of the origins of 18 men whose remains were found in the wreck of the Mary Rose, Henry VIII's warship, which sank in 1545. They conclude that a high proportion of the ship's crew were foreigners and that this may have contributed to confusion on board ship and the sinking of the vessel. We have re-evaluated the data of Bell et al. and conclude that only one of the 18 sailors demonstrably spent his childhood outside the British Isles.     

Phenetics,cladistics, and the search for the Alaskan ancestors of the Paleoindians: a reassessment of relationships among the Clovis,Nenana, and Denali archaeological complexes

Clovis, Nenana, and Denali are the earliest well-documented archaeological complexes in the New World. Clovis has been found at sites throughout the lower 48 states of the USA and in parts of Canada but not in Alaska, whereas Nenana and Denali have been found in Alaska but not elsewhere in North America. In 1991, Goebel and colleagues reported phenetic analyses of tool types from Clovis, Nenana, and Denali. They found that Nenana clustered more closely with Clovis than with Denali, and concluded from this that Nenana was likely ancestral to Clovis. Goebel et al.'s study has been cited frequently since it was published, and their conclusions have been widely accepted. Here we explain why analyses of the type performed by Goebel et al. are problematic and also demonstrate empirically that their results are dependent on the algorithm and distance measure used. We then reanalyze their dataset with a technique from biology called cladistics. Cladistics has replaced phenetics as the method of choice for reconstructing evolutionary relationships in biology, because it is more objective. The results of this analysis differ from those obtained by Goebel and colleagues. The results strongly suggest that Denali and Clovis are in fact more closely related to each other than either is to Nenana.     

Sickle blade life-history and the transition to agriculture: an early Neolithic case study from Southwest Asia

In Southwest Asia, sickle blades first appear early in the sequence of the transition to agriculture. In the past, detailed qualitative research on silica bearing blade stone tools focus on the characterization of use-wear traces such as polish types and accrual rates. In this paper we approach the study of sickle blades slightly different, choosing to examine tool life-history by developing a method to quantitatively estimate harvesting intensity. The method centers on an experiment of cutting cereal stalks and measuring stone blade edge thickness under a scanning electron microscope as a proxy for cutting time. We end with regressing the experimental results to provide an estimation of how intensively archaeological sickle blades recovered from the site of Dhra’, Jordan were used for harvesting. The results, while preliminary, enable an initial interpretation of sickle blades as important tools with long use-life histories during the early Neolithic in the Southern Levant.     

Independent confirmation of a diagnostic sheep/goat peptide sequence through DNA analysis and further exploration of its taxonomic utility within the Bovidae

Buckley et al. (2010) recently identified a Type I collagen (COL1A2) peptide sequence that discriminates between sheep and goat species. The exact location of this peptide sequence on the genome was not reported. We identified the sequence's location and developed a PCR based approach that amplifies the diagnostic sequence from exon 41 of the COL1A2 gene. Using DNA analysis, we confirmed that this COL1A2 peptide discriminates between goat and sheep species reliably, but is limited as a more general phylogenetic marker.     

Applying new approaches to modeling diet and status: isotopic evidence for commoner resiliency and elite variability in the Classic Maya lowlands

Classic Maya states were characterized by a high degree of socioeconomic stratification. This paper investigates the degree to which status, as defined by grave goods and tomb construction, influenced dietary patterns of elites and commoners throughout the Classic Period (200–900/1000 AD) of the southern lowlands. We compile a database (N = 102) of previously-published stable isotope ratios (δ¹³C collagen, δ¹³C apatite, and δ¹⁵N collagen) from Maya bone mineral and collagen, and interrogate these data through two new isotopic modeling techniques: a simple carbon isotope model ( Kellner and Schoeninger, 2007; Froehle et al., 2010) and a multivariate isotope model ( Froehle et al., 2012). We find that Maya elite diet varied significantly through time in terms of maize consumption and trophic level, while commoner diet remained remarkably stable. These findings provide new information relevant to studies of ancient Maya class structure and to studies of subsistence strategies of the pre-Columbian Americas.     

Gloss and use-wear traces on flint sickles and similar phenomena

Using a scanning electron microscope, the high optical polish or gloss and other use-wear traces on the edges of sickle blades are characterized and compared with polishes on other artifacts and natural pieces. The photomicrographs of the surface features and cross sections of the sickle blades as well as laboratory simulation tests, show that the gloss does not form an additive surface layer. Instead, polish formation is considered to be the result of surface alteration caused by frictional mechanisms. Use-wear traces also suggest evidence of how and on what crop the sickles were used.     

New insights about the construction and use of shell mounds from the geochemical analysis of mollusks: an example from the greater San Francisco Bay

A new method developed by Schweikhardt et al. (2011) for the geochemical analysis of bay mussels is applicable (when combined with radiocarbon assessments) for examining the seasonal construction patterns and growth cycles of coastal mound sites over time. Ideally suited for the analysis of mollusk fragments in museum collections, this method allows archaeologists to evaluate divergent models about the functions of mound sites, as well as the mobility practices and social organizations of the mound builders. In this case study, the method is employed to examine two adjacent mounds (Ellis Landing, Brooks Island) in the San Francisco Bay Area, California to assess whether their occupants may have participated in a broader multi-site community dating to the Late Period (1100–250 BP).     

Pre-Clovis in Texas? A critical assessment of the “Buttermilk Creek Complex”

Lithic artifacts from the lowest strata of the Debra L. Friedkin site, located on Buttermilk Creek in central Texas, have been interpreted as an undisturbed pre-Clovis assemblage (Waters et al., 2011a). Stone tools and debitage were recovered from sediments stratified just below diagnostic Clovis artifacts and dated by OSL to between 13.2 and >15.5 cal kya. Invoking commonly observed cultural and natural site formation processes, we offer an alternative explanation of the “Buttermilk Creek Complex” as a Clovis assemblage in secondary association with the dated sediments.     

Comments on Richards et al., Journal of Archaeological Science 35, 2008 “Strontium isotope evidence of Neanderthal mobility at the site of Lakonis,Greece using laser-ablation PIMMS”

We present an evaluation of the laser ablation Sr isotope data reported by Richards et al. [Richards, M., Harvati, K., Grimes, V., Colin Smith, C., Smith, T., Jean-Jacques Hublin, J.J., Karkanas, P., and Panagopoulou, E., 2008. Strontium isotope evidence of Neanderthal mobility at the site of Lakonis, Greece using laser ablation PIMMS. Journal of Archaeological Science 35, 1251–1256] for a Neanderthal tooth recovered from a site in Greece. Based on an alternative and analytically more robust method of correcting for isobaric interferences present during the analysis the tooth appears to be isotopically homogenous and within uncertainty of the value for modern seawater. If this is the case then contrary to the migration model proposed by Richards et al. [Richards, M., Harvati, K., Grimes, V., Colin Smith, C., Smith, T., Jean-Jacques Hublin, J.J., Karkanas, P., and Panagopoulou, E., 2008. Strontium isotope evidence of Neanderthal mobility at the site of Lakonis, Greece using laser ablation PIMMS. Journal of Archaeological Science 35, 1251–1256] the Neanderthal individual may have actually been a coastal dweller and lived within the vicinity of the find site.     

Debates over Palaeolithic chronology – the reliability of C is confirmed

The debate about the complex issues of human development during the Middle to Upper Palaeolithic transition period (45–35 ka BP) has been hampered by concerns about the reliability of the radiocarbon dating method. Large ¹⁴C anomalies were postulated and radiocarbon dating was considered flawed. We show here that these issues are no longer relevant, because the large anomalies are artefacts beyond plausible physical limits for their magnitude. Previous inconsistencies between ¹⁴C radiocarbon datasets have been resolved, and a new radiocarbon calibration curve, IntCal09 (Reimer et al., 2009), was created. Improved procedures for bone collagen extraction and charcoal pre-treatment generally result in older ages, consistent with independently dated time markers.     

The Study of Attic Black Gloss Sherds using Synchrotron X-ray Diffraction

We have studied the mineral composition of the gloss and the ceramic body of three pieces of Attic Greek pottery by applying the technique of high-resolution powder diffraction using synchroton X-rays. The measurements were performed on Stations 2·3 and 9·1 at the Synchrotron Radiation Source, Daresbury Laboratory. High quality powder patterns from the bulk of the ceramics and from the gloss surfaces have been obtained. The diffraction results show interesting variations of mineral composition between the gloss of the different sherds as well as variations between the bulk and the gloss. This makes phase identification and comparison between different fabrics less ambiguous. Spinel minerals are present in the gloss which are absent in the main body of the ceramics. Diffraction lines from one surface match the patterns of hematite, magnetite/maghemite and hercynite, while solid solutions of spinel structures appear to be present in the gloss layer of another sample. Crystallite particle sizes and lattice parameters of the minerals in the gloss layer have been accurately determined. Supplementary scanning electron microscopy (SEM) reveals the gloss thickness to be approximately 20 μm but with variations down to 5 μm. Analysis of the diffraction profile for the hematite component reveals a particle size in the order of 0·027 μm.     

The Emirate of Córdoba (756–929 AD) and the introduction of the Egyptian mongoose (Herpestes ichneumon) in Iberia: the remains from Muge,Portugal

We describe new finds of Herpestes ichneumon (Egyptian mongoose) from an archaeological context in Portugal, directly ¹⁴C dated to c. 800 AD. This is at least two centuries older than a previously reported find of this species from Andalusia (southern Spain; Riquelme-Cantal et al., 2008). Our finding provides further support to the hypothesis that the Muslims introduced this animal to the Iberian Peninsula. In particular, we suggest that Berber settlers might have brought it some time during the Umayyad conquest of Iberia or with the establishment of the Emirate of Córdoba.     

Should dates trump context? Evaluation of the Cave 7 skeletal assemblage radiocarbon dates

“Massacre” was the accepted interpretation for a prehistoric skeletal assemblage of around 90 individuals from Cave 7 in the SE Utah of the North American Southwest since the 1890s. Coltrain and others (Journal of Archaeological Science 39, 2220–2230) rejected this account based on a dispersed suite of AMS radiocarbon dates on purified bone collagen from the interred individuals. Since dates from skeletons exhibiting perimortem damage were scattered across some 400 radiocarbon years, Coltrain et al. argued for multiple interments of victims of violence and related kin spread across several centuries. The temporal placement of interment events in Cave 7 clearly cannot be known independent of radiocarbon assays but such assays should not be privileged above contextual information about which individuals were interred together unless verified by an independent dating laboratory. Only by ignoring important information about burial context in the 1893 field record can the dates of Coltrain et al. be accepted as accurate estimates of time of death. We redated residual collagen from 11 of the Cave 7 individuals because of significant contextual anomalies with some of the prior results. The new assays combined with contextual evidence demonstrate that some of Coltrain et al.’s dates are either too old or too young; the dates are neither sufficiently accurate (true estimates of sample age) nor sufficiently precise (small confidence intervals) to refute a single-event massacre or to confirm multiple interment events in Cave 7. Nonetheless, dates that meet these criteria disclose at least two interment events, a large one of mostly adult males, many exhibiting perimortem damage (a massacre assemblage), and a small one consisting of an adult female with three children. A third interment event of a few adult females and child is possible based primarily on context since the date distribution in this case overlaps substantially with that of the massacre victims; context also hints at other interment events. Aside from chronology we clarify the number of Basketmaker individuals interred at the site and the incidence of perimortem violence. A single-event mass killing continues to be the most likely interpretation for around 58 individuals, mostly adult males (at least 35) but also adult females and children. This incident occurred between cal. AD 20–80 and doubtless had a significant social impact at the time because of its scale, reverberating throughout the early farming communities of the Southwest.     

Multitemporal analysis for preservation of obsidian sources from Melka Kunture (Ethiopia): integration of fieldwork activities,digital aerial photogrammetry and multispectral stereo-IKONOS II analysis

An integrated analysis of recent satellite imageries and dated aerial photos demonstrated to be a good investigation tool (Gallo et al., 2009) for the identification of new sites and for the assessment of landscape changes of wide archaeological areas in Ethiopia.