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Ethnohistoric accounts indicate that the people of Australia's Channel Country engaged in activities rarely recorded elsewhere on the continent, including food storage, aquaculture and possible cultivation, yet there has been little archaeological fieldwork to verify these accounts. Here, the authors report on a collaborative research project initiated by the Mithaka people addressing this lack of archaeological investigation. The results show that Mithaka Country has a substantial and diverse archaeological record, including numerous large stone quarries, multiple ritual structures and substantial dwellings. Our archaeological research revealed unknown aspects, such as the scale of Mithaka quarrying, which could stimulate re-evaluation of Aboriginal socio-economic systems in parts of ancient Australia.

Bioarchaeological research in Australia has lagged behind that in other regions due to understandable concerns arising from the disregard of Indigenous Australians rights over their ancestors’ remains. To improve this situation, bioarchaeologists working in Australia need to employ more community-oriented approaches to research. This paper reports a project in which we employed such an approach. The project focused on burials in the Flinders Group, Queensland. Traditional Owners played a key role in the excavations and helped devise analyses that would deliver both scientific contributions and socially relevant outcomes. The fieldwork and laboratory analyses yielded a number of interesting results. Most significantly, they revealed that the pattern of mortuary practices recorded by ethnographers in the region in the early 20th century—complex burial of powerful people and simple interment of less important individuals—has a time depth of several hundred years or more. More generally, the project shows that there can be fruitful collaboration between archaeologists and Indigenous communities in relation to the excavation and scientific analysis of Aboriginal ancestral remains.

The ability to control fire clearly had a significant impact on human evolution, but when and how hominins developed this ability remains poorly understood. Improving our understanding of the history of hominin fire use will require not only additional fieldwork but also comparative analyses of fire use by ethnographically-documented hunter-gatherer groups. Here, we report a study that focused on the second of these tasks. In the study, we consulted ethnographic texts for a sample of 93 hunter-gatherer groups and collected data pertaining to fire use in settlements. We focused on the groups’ methods of making fire, the ways in which they used fire, and when and where they created fires. While many of the observations were in line with expectations, some were surprising. Perhaps most notably, we found that several groups did not know how to make fire and that even within some of the groups who were able to make fire, the relevant knowledge was restricted to a very small number of individuals. Another surprising finding was that many groups preferred to preserve fire rather than creating it anew, to the point that they would carry it between camps. In the final section of the paper, we discuss the implications of the survey’s findings for understanding the early archaeological record of fire use.

In this paper we outline a worked example of the combined use of genetic data and archaeological evidence. The project focuses on Queensland’s Cape York Peninsula and has two goals. One is to shed ...

It has been estimated that up to 25% of Indigenous human remains held in Australian institutions are unprovenanced. Geochemical tracers like strontium isotope ratios ( Sr/ Sr) have been used globally for over 40 years to discern human provenance and provide independent data to aid in repatriation efforts. To reliably apply this technology, landscape Sr/ Sr isotope ratio variability must be quantified. In Australia, only a few studies have used this technique and they are lacking in detail. Here, we present Australia's first regional strontium isotope ratio variability study. We measured strontium isotope ratios in soil, plant, water, and faunal material throughout Cape York, Queensland, the most northerly point of mainland Australia. Results show a close correlation between surface soil leachates, vegetation, surface water, and faunal Sr/ Sr results with extremely high values (0.78664) associated with ancient Precambrian geology. Our study suggests that measuring Sr/ Sr in soil and plant samples offer a reliable approach for assessing regional Sr isotope distribution, although the inclusion of mammal and freshwater samples is also important to assess exogenous inputs. This study provides an important tool for modern and prehistoric provenance studies and may aid in answering some of Australia's most enduring archaeological questions.

Isotopic analyses of human remains have the potential to alter our understanding of prehistoric lifeways and migration in Australia, but very few such analyses have been conducted in the country to date. Here, we report the first regional multiproxy isotope study of pre-contact human remains from Australia. We obtained δ13Ccollagen, δ15Ncollagen, δ18Obioapatite, δ13Cbioapatite and 87Sr/86Sr isotope values from three complex interments and two simple beach burials from the Flinders Group of Islands, Queensland. The study had two goals. One was to assess how the diets of the individuals compared to those of pre-contact populations elsewhere in the region. The other goal was to test the hypothesis that burial type was indicative of local/non-local status. We found that the individuals’ diets were diverse and included a relatively high percentage of low trophic level foods. With regard to the difference in burial practices, we found those afforded complex burials had grown up in the Flinders Group, while those given beach burials likely grew up away from the islands. These results highlight the intricacies of the lives of the Indigenous Australians who inhabited the islands and inform our understanding of their pre-contact diet and mobility. The results also suggest that multiproxy isotope studies may be able to aid with the repatriation of unprovenanced remains of Indigenous Australians.

The settlement of Iceland in the Viking Age has been the focus of much research, but the composition of the founding population remains the subject of debate. Some lines of evidence suggest that almost all the founding population were Scandinavian, while others indicate a mix of Scandinavians and people of Scottish and Irish ancestry. To explore this issue further, we used three-dimensional techniques to compare the basicrania of skeletons from archaeological sites in Iceland, Scandinavia, and the British Isles. Our analyses yielded two main results. One was that the founding population likely consisted of roughly equal numbers of Scandinavians and people from the British Isles. The other was that the immigrants who originated from the British Isles included individuals of southern British ancestry as well as individuals of Scottish and Irish ancestry. The first of these findings is consistent with the results of recent analyses of modern and ancient DNA, while the second is novel. Our study, therefore, strengthens the idea that the founding population was a mix of Scandinavians and people from the British Isles, but also raises a new possibility regarding the regions from which the settlers originated.

The Viking maritime expansion from Scandinavia (Denmark, Norway, and Sweden) marks one of the swiftest and most far-flung cultural transformations in global history. During this time (c. 750 to 1050 CE), the Vikings reached most of western Eurasia, Greenland, and North America, and left a cultural legacy that persists till today. To understand the genetic structure and influence of the Viking expansion, we sequenced the genomes of 442 ancient humans from across Europe and Greenland ranging from the Bronze Age (c. 2400 BC) to the early Modern period (c. 1600 CE), with particular emphasis on the Viking Age. We find that the period preceding the Viking Age was accompanied by foreign gene flow into Scandinavia from the south and east: spreading from Denmark and eastern Sweden to the rest of Scandinavia. Despite the close linguistic similarities of modern Scandinavian languages, we observe genetic structure within Scandinavia, suggesting that regional population differences were already present 1,000 years ago. We find evidence for a majority of Danish Viking presence in England, Swedish Viking presence in the Baltic, and Norwegian Viking presence in Ireland, Iceland, and Greenland. Additionally, we see substantial foreign European ancestry entering Scandinavia during the Viking Age. We also find that several of the members of the only archaeologically well-attested Viking expedition were close family members. By comparing Viking Scandinavian genomes with present-day Scandinavian genomes, we find that pigmentation-associated loci have undergone strong population differentiation during the last millennia. Finally, we are able to trace the allele frequency dynamics of positively selected loci with unprecedented detail, including the lactase persistence allele and various alleles associated with the immune response. We conclude that the Viking diaspora was characterized by substantial foreign engagement: distinct Viking populations influenced the genomic makeup of different regions of Europe, while Scandinavia also experienced increased contact with the rest of the continent.

We report a study in which we systematically reviewed the recent literature dealing with human-environment interaction in prehistory. We first identified the 165 most highly cited papers published ...

Hand images with missing phalanges occur at a number of Upper Palaeolithic rock art sites in Europe. It has been argued that they represent hand signals or a counting system, but there are reasons to believe they were actually produced by hands from which finger segments had been removed. Here, we report a cross-cultural study designed to shed light on this phenomenon. Our review of the ethnographic literature identified 121 societies from Africa, Asia, the Americas, and Oceania that engaged in finger segment amputation, and we were able to distinguish ten distinct amputation practices within this sample. When the contexts and what we can infer about the participants are taken into account, the scenario that best fits the rock art hand images is removal of finger segments during life in order to appeal for supernatural assistance. This has potentially interesting implications for social life in the Upper Palaeolithic because traumatic religious rituals have been found to foster strong interpersonal bonds among group members and hostility towards members of other groups.

Cycles are widely considered to be an important feature of environmental and human history over the last 50,000 years. However, there is an overlooked problem in the investigation of cyclicity in this time period—the standard statistical methods for identifying cycles assume that observations are precisely dated, but the main relevant dating technique, radiocarbon dating, often yields dates with large and highly irregular uncertainties. Here, we present the results of a massive simulation study that explored the impact of radiocarbon dating uncertainty on our ability to identify cycles in time-series. Our results suggest there is indeed a problem. We found that, at best, we could correctly identify known cycles only 42% of the time and that the false-positive rate was as high as 90%. This indicates that an individual analysis of a single time-series is very likely to return false-positive cycles. One implication of this is that many of the environmental and sociopolitical cycles that have been identified may not be real. Consequently, a program of reassessment is needed.

This study focuses on two hypotheses at the heart of a debate concerning cooperation, socio-political complexity, and religious belief. One of these contends that moralizing high gods (MHGs) were c...

The impact of climate change on conflict is an important but controversial topic. One issue that needs to be resolved is whether or not climate change exacerbates conflict over the long term. With this in mind, we investigated the relationship between climate change and conflict among Classic Maya polities over a period of several hundred years (363–888 CE). We compiled a list of conflicts recorded on dated monuments, and then located published temperature and rainfall records for the region. Subsequently, we used a recently developed time-series method to investigate the impact of the climatic variables on the frequency of conflict while controlling for trends in monument number. We found that there was a substantial increase in conflict in the approximately 500 years covered by the dataset. This increase could not be explained by change in the amount of rainfall. In contrast, the increase was strongly associated with an increase in summer temperature. These finding have implications not only for Classic Maya history but also for the debate about the likely effects of contemporary climate change.

Objectives The causes of variation in breastfeeding duration in humans are poorly understood, but life history factors related to maternal energetics drive much of the variation in lactation duration in nonhuman animals. With this in mind, we investigated whether four energy-related factors influence variation in breastfeeding duration in a non-industrial human population: (1) mortality risk during mother's development (assessed via mother's adult height), (2) reliance on nutrient-dense weaning foods, (3) access to and need for help with infant feeding and care (“allomaternal care”), and (4) maternal tradeoffs between current and future reproduction (measured via child's birth order). Materials and methods The data pertain to 51 Kakchiquel-speaking Maya mothers and 283 children from a village in rural Guatemala. We developed a linear mixed model to evaluate the relationships between breastfeeding duration and the energy-related factors. Results Duration of breastfeeding was associated with two of the energy-related factors in the ways we predicted but not with the other two. Contrary to predictions, taller mothers breastfed for shorter periods and we found no evidence that weanling diet quality impacts breastfeeding duration. As predicted, women who had more help with infants breastfed for shorter periods, and later-born infants breastfed longer than earlier-born ones. Discussion The results regarding allomaternal care suggest that help reduces mothers' lactation demands. The energy saved may be redirected to increasing fecundity or investment in other children. The birth order result suggests that children born to mothers nearing reproductive senescence receive higher levels of investment, which likely impacts children's fitness.

The goal of this paper is to provoke debate about the nature of an iconic artifact—the Acheulean handaxe. Specifically, we want to initiate a conversationabout whether or not they are cultural objects. The vast majority of archeologistsassume that the behaviors involved in the production of handaxes wereacquired by social learning and that handaxes are therefore cultural. We willargue that this assumption is not warranted on the basis of the available evidenceand that an alternative hypothesis should be given serious consideration.This alternative hypothesis is that the form of Acheulean handaxes was at leastpartly under genetic control.

Estimating body mass from skeletal material is a key task for many biological anthropologists. As a result, several sets of regression equations have been derived for cranial and postcranial material. The equations have been applied to a wide range of specimens, but several factors suggest they may not be as reliable as generally assumed. Specifically, since many of the equations were derived from small reference samples using proxies for key variables and/or mean data, the nature of the relationship between the skeletal variables and body mass has often not been adequately demonstrated. In addition, few of the equations have been validated on known samples, making their accuracy and precision uncertain. Lastly, because no study has used cranial and postcranial material from the same individuals, the two approaches have never been systematically compared. The present study responded to these issues by deriving new regression equations from cranial and postcranial material using a large sample of modern humans of known-mass and associated skeletal variables measured from CT data. The equations were then tested on an independent sample, also of known mass. The results show that the newly derived equations estimate mass more accurately than existing equations for most variables. However, improvements were modest and accuracy rates remained relatively low. In addition, variables that had previously been argued to be ideal predictors were not the most accurate, and the current criteria used to assess equations did not ensure reliability. Overall, the results suggest that body mass estimates must be used cautiously and that further research is required.

Many inferences in palaeoanthropology and bioarchaeology rely on estimates of body mass from skeletal material. Body mass estimation is also becoming an area of interest for forensic anthropologists. The most common approach to estimating body mass from the skeleton involves measurements of the postcranium, and a number of equations have been developed for femoral head size and stature plus bi-iliac breadth. These equations have become standard in biological anthropology, but they have rarely been tested on individuals of known mass. In addition, the effects of several assumptions involved in the application of the equations have not been rigorously investigated. Accordingly, this study employed CT scans from a sample of 253 adult modern humans of known body mass to test the accuracy of the most widely used postcranial body mass estimation equations. The results were then used to evaluate several claims concerning the performance of the equations relative to one another. Most of the equations that were tested met the criteria for acceptance as reliable estimators with the male and the combined-sex samples. However, females were not estimated as reliably. In addition, the equations did not always perform consistently or as expected. Overall, our results suggest that estimating body mass with the postcranial equations that are currently available requires more caution than is usually exercised.

This paper reports a study that sheds light on an issue that is important for understanding human behavioral evolution—the factors that influence hunter-gatherers’ decisions regarding the number and degree of specialization of their tools. Two primary drivers of technological richness and complexity have been proposed in the anthropological literature: population size and environmental risk. In general, ethnographic studies tend to support environmental risk as the primary driver, whereas the limited number of archaeological studies that have been carried out seem to support population size. These findings are difficult to reconcile because problems exist for both sets of studies. The present study was designed with these problems in mind. We used an archaeological dataset to test which of the hypothesized driving factors—population size or environmental risk—best explains changes in technological richness. More specifically, we investigated whether changes in the number of point types in Texas from the first occupation more than 13,000 years ago to the Late Prehistoric period, around 400 years ago, are better explained by environmental risk or by population size. Bivariate correlations and a generalized linear model indicate that temporal changes in point-type richness in Texas are significantly associated with changes in one of our proxies of risk—global temperature. We found no relationship between temporal changes in point-type richness and changes in population size. Thus, the results derived from this study are consistent with the environmental risk hypothesis and inconsistent with the population size hypothesis.

A number of putative adaptations for bipedalism have been identified in the hominin spine. However, it is possible that some have been overlooked because only a few studies have used 3D and these studies have focused on cervical vertebrae. With this in mind, we used geometric morphometric techniques to compare the 3D shapes of three thoracic and two lumbar vertebrae of Homo sapiens, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus. The study had two goals. One was to confirm the existence of traits previously reported to distinguish the thoracic and lumbar vertebrae of H. sapiens from those of the great apes. The other was to, if possible, identify hitherto undescribed traits that differentiate H. sapiens thoracic and lumbar vertebrae from those of the great apes. Both goals were accomplished. Our analyses not only substantiated a number of traits that have previously been discussed in the literature but also identified four traits that have not been described before: (1) dorsoventrally shorter pedicles in the upper thoracic vertebrae; (2) dorsoventrally longer laminae in all five of the vertebrae examined; (3) longer transverse processes in the upper thoracic vertebrae; and (4) craniocaudally ‘pinched’ spinous process tips in all of the vertebrae examined. A review of the biomechanical literature suggests that most of the traits highlighted in our analyses can be plausibly linked to bipedalism, including three of the four new ones. As such, the present study not only sheds further light on the differences between the spines of H. sapiens and great apes but also enhances our understanding of how the shift to bipedalism affected the hominin vertebral column.

Thermoregulation is widely believed to have influenced body size and shape in the two best-known extinct members of genus Homo , Homo erectus and Homo neanderthalensis , and to have done so in contrasting ways. H. erectus is thought to have been warm adapted, while H. neanderthalensis is widely held to have been cold adapted. However, the methods that have been used to arrive at these conclusions ignore differences among body segments in a number of thermoregulation-related variables. We carried out a study designed to determine whether the current consensus regarding the thermoregulatory implications of the size and shape of the bodies of H. erectus and H. neanderthalensis is supported when body segment differences in surface area, skin temperature , and rate of movement are taken into account.

Henrich and his large group of cosigners (1) miss the point of our paper (2). They believe we were rejecting the relevance of population size in cultural evolution outright, whereas we were critiquing the recent trend in archaeology to use population size to explain patterns in the archaeological record; hence, our title “Population size does not explain past changes in cultural complexity” (2). Perhaps not surprisingly given their misreading of our paper, none of Henrich et al.’s points (1) contradicts our argument. We argued that the recent wave of studies in which population size is claimed to explain past changes in cultural complexity is problematic. One cause for concern, we averred, is that the models that … [↵][1]1To whom correspondence should be addressed. Email: k.vaesen{at}tue.nl. [1]: #xref-corresp-1-1

Recently, it has become commonplace to interpret major transitions and other patterns in the Palaeolithic archaeological record in terms of population size. Increases in cultural complexity are claimed to result from increases in population size; decreases in cultural complexity are suggested to be due to decreases in population size; and periods of no change are attributed to low numbers or frequent extirpation. In this paper, we argue that this approach is not defensible. We show that the available empirical evidence does not support the idea that cultural complexity in hunter–gatherers is governed by population size. Instead, ethnographic and archaeological data suggest that hunter–gatherer cultural complexity is most strongly influenced by environmental factors. Because all hominins were hunter–gatherers until the Holocene, this means using population size to interpret patterns in the Palaeolithic archaeological record is problematic. In future, the population size hypothesis should be viewed as one of several competing hypotheses and its predictions formally tested alongside those of its competitors.This article is part of the themed issue ‘Major transitions in human evolution’.

Demography is increasingly being invoked to account for features of the archaeological record, such as the technological conservatism of the Lower and Middle Pleistocene, the Middle to Upper Paleolithic transition, and cultural loss in Holocene Tasmania. Such explanations are commonly justified in relation to population dynamic models developed by Henrich [Henrich J (2004) Am Antiq 69:197-214] and Powell et al. [Powell A, et al. (2009) Science 324(5932):1298-1301], which appear to demonstrate that population size is the crucial determinant of cultural complexity. Here, we show that these models fail in two important respects. First, they only support a relationship between demography and culture in implausible conditions. Second, their predictions conflict with the available archaeological and ethnographic evidence. We conclude that new theoretical and empirical research is required to identify the factors that drove the changes in cultural complexity that are documented by the archaeological record.

Osseous (bone and ivory) rods dating to the Early Paleoindian period (ca. 13,300–11,900 calendar years before present) have been found over much of North America. Previous researchers have attributed several possible functions to these artifacts, including use as projectile points, as foreshafts, as pressure-flaker handles, as sled shoes, and as levered hafting wedges. Considering the important link that osseous rods provide between the late Pleistocene cultures of North America and the Upper Paleolithic cultures of Europe and Asia, it is crucial that archaeologists define the range of variation and possible functions represented in the North American osseous rods. In this chapter we provide an up-to-date review of the distribution of late Pleistocene osseous rods across North America; describe the range of variation in morphology and attributes associated with this sample; and discuss the possible range of functions represented.

© 2014 Munson et al. Religious rituals that are painful or highly stressful are hypothesized to be costly signs of commitment essential for the evolution of complex society. Yet few studies have investigated how such extreme ritual practices were culturally transmitted in past societies. Here, we report the first study to analyze temporal and spatial variation in bloodletting rituals recorded in Classic Maya (ca. 250-900 CE) hieroglyphic texts. We also identify the sociopolitical contexts most closely associated with these ancient recorded rituals. Sampling an extensive record of 2,480 hieroglyphic texts, this study identifies every recorded instance of the logographic sign for the word ch'ahb' that is associated with ritual bloodletting. We show that documented rituals exhibit low frequency whose occurrence cannot be predicted by spatial location. Conversely, network ties better capture the distribution of bloodletting rituals across the southern Maya region. Our results indicate that bloodletting rituals by Maya nobles were not uniformly recorded, but were typically documented in association with antagonistic statements and may have signaled royal commitments among connected polities.

Recent work suggests that global variation in toolkit structure among hunter-gatherers is driven by risk of resource failure such that as risk of resource failure increases, toolkits become more diverse and complex. Here we report a study in which we investigated whether the toolkits of small-scale farmers and herders are influenced by risk of resource failure in the same way. In the study, we applied simple linear and multiple regression analysis to data from 45 small-scale food-producing groups to test the risk hypothesis. Our results were not consistent with the hypothesis; none of the risk variables we examined had a significant impact on toolkit diversity or on toolkit complexity. It appears, therefore, that the drivers of toolkit structure differ between hunter-gatherers and small-scale food-producers.

It has long been argued that the form of North American Paleoindian points was affected by hafting. According to this hypothesis, hafting constrained point bases such that they are less variable than point blades. The results of several studies have been claimed to be consistent with this hypothesis. However, there are reasons to be skeptical of these results. None of the studies employed statistical tests, and all of them focused on points recovered from kill and camp sites, which makes it difficult to be certain that the differences in variability are the result of hafting rather than a consequence of resharpening. Here, we report a study in which we tested the predictions of the hafting hypothesis by statistically comparing the variability of different parts of Clovis points. We controlled for the potentially confounding effects of resharpening by analyzing largely unused points from caches as well as points from kill and camp sites. The results of our analyses were not consistent with the predictions of the hypothesis. We found that several blade characters and point thickness were no more variable than the base characters. Our results indicate that the hafting hypothesis does not hold for Clovis points and indicate that there is a need to test its applicability in relation to post-Clovis Paleoindian points.

A number of functions have been proposed for cached Clovis points. The least complicated hypothesis is that they were intended to arm hunting weapons. It has also been argued that they were produced for use in rituals or in connection with costly signaling displays. Lastly, it has been suggested that some cached Clovis points may have been used as saws. Here we report a study in which we morphometrically compared Clovis points from caches with Clovis points recovered from kill and camp sites to test two predictions of the hypothesis that cached Clovis points were intended to arm hunting weapons: 1) cached points should be the same shape as, but generally larger than, points from kill/camp sites, and 2) cached points and points from kill/camp sites should follow the same allometric trajectory. The results of the analyses are consistent with both predictions and therefore support the hypothesis. A follow-up review of the fit between the results of the analyses and the predictions of the other hypotheses indicates that the analyses support only the hunting equipment hypothesis. We conclude from this that cached Clovis points were likely produced with the intention of using them to arm hunting weapons.

It has been proposed that strain-related phenotypic plasticity may be a major confounding factor in attributing hominin fossils to species. The study reported here tested this hypothesis with craniometric data from the great apes and Colobus guereza. We divided the measurements into three groups: measurements of features subject to high masticatory strain, measurements of features subject to low-to-moderate masticatory strain, and measurements of features that do not remodel and therefore are not prone to strain-related phenotypic plasticity. Next, we used the coefficient of variation and ANOVA to investigate whether masticatory strain is a cause of variability. These analyses partially supported the hypothesis. The predicted differences between the high-strain measurements and the other measurements were found in the majority of the species. However, the coefficient of variation values for the low-to-moderate strain and non-phenotypically plastic measurements were indistinguishable. Thereafter, we used discriminant function analysis to compare the ability of the three groups of measurements to assign specimens to species. This analysis did not support the hypothesis. The high-strain measurements were less effective than the other measurements, but the low-to-moderate strain measurements were more effective than the non-phenotypically plastic measurements. In addition, better discrimination was achieved when all the measurements were employed than when just the non-phenotypically plastic measurements were utilised. We conclude from this that strain-related phenotypic plasticity is unlikely to impede hominin alpha taxonomic research.

Height and weight-based methods of estimating surface area have played an important role in the development of the current consensus regarding the role of thermoregulation in human evolution. However, such methods may not be reliable when applied to early hominins because their limb proportions differ markedly from those of humans. Here, we report a study in which this possibility was evaluated by comparing surface area estimates generated with the best-known height and weight-based method to estimates generated with a method that is sensitive to proportional differences. We found that the two methods yield indistinguishable estimates when applied to taxa whose limb proportions are similar to those of humans, but significantly different results when applied to taxa whose proportions differ from those of humans. We also found that the discrepancy between the estimates generated by the two methods is almost entirely attributable to inter-taxa differences in limb proportions. One corollary of these findings is that we need to reassess hypotheses about the role of thermoregulation in human evolution that have been developed with the aid of height and weight-based methods of estimating body surface area. Another is that we need to use other methods in future work on fossil hominin body surface areas.