Ariane Burke

Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada

The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the “Beringian standstill hypothesis”, which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

Women Who Know Their Place

Differences between men and women in the performance of tests designed to measure spatial abilities are explained by evolutionary psychologists in terms of adaptive design. The Hunter-Gatherer Theory of Spatial Ability suggests that the adoption of a hunter-gatherer lifestyle (assuming a sexual division of labor) created differential selective pressure on the development of spatial skills in men and women and, therefore, cognitive differences between the sexes. Here, we examine a basic spatial skill—wayfinding (the ability to plan routes and navigate a landscape)—in men and women in a natural, real-world setting as a means of testing the proposition that sex-based differences in spatial ability exist outside of the laboratory. Our results indicate that when physical differences are accounted for, men and women with equivalent experience perform equally well at complex navigation tasks in a real-world setting. We conclude that experience, gendered patterns of activity, and self-assessment are contributing factors in producing previously reported differences in spatial ability.

The role of spatial foresight in models of hominin dispersal

Increasingly sophisticated hominin cognition is assumed to play an important role in major dispersal events but it is unclear what that role is. We present an agent-based model showing that there is a close relationship between level of foresight, environmental heterogeneity, and population dispersibility. We explore the dynamics between these three factors and discuss how they may affect the capacity of a hominin population to disperse. Generally, we find that high levels of environmental heterogeneity select for increased foresight and that high levels of foresight tend to reduce dispersibility. This suggests that cognitively complex hominins in heterogeneous environments have low dispersibility relative to cognitively less complex organisms in more homogeneous environments. The model predicts that the environments leading up to major episodes of dispersal, such as the initial hominin dispersal into Eurasia, were likely relatively low in spatial heterogeneity and that the dispersing hominins had relatively low foresight.

Reading the landscape: Legible environments and hominin dispersals.

Wayfinding, or the ability to plan and navigate a course over the landscape, is a subject of investigation in geography, neurophysiology, psychology, urban planning, and landscape design. With the prevalence of GPS‐assisted navigation systems, or “wayfinders,” computer scientists are also increasingly interested in understanding how people plan their movements and guide others. However, the importance of wayfinding as a process that regulates human mobility has only recently been incorporated into archeological research design. Hominin groups were able to disperse widely during the course of prehistory. The scope of these dispersals speaks to the innate navigation abilities of hominins. Their long‐term success must have depended on an ability to communicate spatial information effectively. Here, we consider the extent to which some landscapes may have been more conducive to wayfinding than others. We also describe a tool we have created for quantifying landscape legibility (sensu Gollege ), a complex and under‐explored concept in archeology, with a view to investigating the impact of landscape structure on human wayfinding and thus, patterns of dispersal during prehistory. To this end, we have developed a method for quantifying legibility using a Geographic Information System (GIS) and apply it to a test case in prehistoric Iberia.

Comparison of spatial downscaling methods of general circulation models to study climate variability during the Last Glacial Maximum

The extent to which climate conditions influenced the spatial distribution of hominin populations in the past is highly debated. General Circulation Models (GCMs) and archaeological data have been used to address this issue. Most GCMs are 15 not currently capable of simulating past surface climate conditions with sufficiently detailed spatial resolution to distinguish areas of potential hominin habitat, however. In this paper we propose a Statistical Downscaling Method (SDM) for increasing the resolution of climate model outputs in a computationally efficient way. Our method uses a generalized additive model (GAM), calibrated over present-day climatology data, to statistically downscale temperature and precipitation time series from the outputs of a GCM simulating the climate of the Last Glacial Maximum (19-23,000 BP) over Western Europe. Once the 20 SDM is calibrated, we first interpolate the coarse-scale GCM outputs to the final resolution and then use the GAM to compute surface air temperature and precipitation levels using these interpolated GCM outputs and fine resolution geographical variables such as topography and distance from an ocean. The GAM acts as a transfer function, capturing non-linear relationships between variables at different spatial scales and correcting for the GCM biases. We tested three different techniques for the first interpolation of GCM output: bilinear, bicubic, and kriging. The resulting SDMs were evaluated by 25 comparing downscaled temperature and precipitation at local sites with paleoclimate reconstructions based on paleoclimate archives (archaeozoological and palynological data) and the impact of the interpolation technique on patterns of variability was explored. The SDM based on kriging interpolation, providing the best accuracy, was then validated on present-day data outside of the calibration period. Our results show that the downscaled temperature and precipitation values are in good agreement with paleoclimate reconstructions at local sites, and that our method for producing fine-grained paleoclimate 30 simulations is therefore suitable for conducting paleo-anthropological research. It is nonetheless important to calibrate the GAM on a range of data encompassing the data to be downscaled. Otherwise, the SDM is likely to over-correct the coarsegrain data. In addition, the bilinear and bicubic interpolation techniques were shown to distort either the temporal variability

Marie-Isabelle Cattin with contributions by Jehanne Affolter & Sylvie Beyries. Le site magdalénien de Monruz: la vie quotidienne à travers le travail du silex (Archéologie neuchâteloise 51). 315 pages, 326 colour and bw 978-2-940347-54-4 paperback. SFr60 & €50.

The book’s original contribution essentially comprises four case studies: the North Sea, the Sundarbans, the Florida wetlands and the Iraqi Marshlands. These are thoughtfully chosen for their past and present archaeological and socio-political relevance. They are distinct in nature, and reasonably well balanced, although Van de Noort’s experience in the North Sea region shines through making the remaining chapters feel somewhat superficial in comparison; this is entirely forgivable. The number of case studies, however, is too few and they are all from the northern hemisphere. A larger, more globally relevant sample would obviously include African, South American and Australasian examples, all necessary for a truly authoritative contribution on climate change archaeology. With this book, Van de Noort has produced yet another successful monograph that will be useful to scholars and students. It is well written, with plenty of figures, though not always of the highest quality (and perhaps too few archaeological illustrations in favour of low-resolution maps and illustrative photographs). It is, for the most part, well referenced, and incorporates the classics in archaeological method and theory, making room for such diagrams as Grahame Clark’s integrated human-environment system from the 1950s and taking the time to tackle the weaknesses of Jared Diamond’s views. It is telling that Van de Noort states: “the contribution of climate change archaeology to a sustainable future is only a modest one: it is about finding examples of adaptation to the consequences of environmental and climate changes in the past that, in a small way, can help build the socioecological resilience of communities in the present and future” (p. 41). He goes on to argue that we should not be deterred in our study of this field, though, by the end of the book, he concludes: “I do not expect that archaeological research will significantly alter the findings from climate change science, or necessarily provide big solutions for the problems we will encounter” (p. 235). The reader will be forgiven for feeling left wanting more, and perhaps this is intended.