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

Bones of recent mammals in the Amboseli Basin, southern Kenya, exhibit distinctive weathering characteristics that can be related to the time since death and to the local conditions of temperature, humidity and soil chemistry. A categorization of weathering characteristics into six stages, recognizable on descriptive criteria, provides a basis for investigation of weathering rates and processes. The time necessary to achieve each successive weathering stage has been calibrated using known-age carcasses. Most bones decompose beyond recognition in 10 to 15 yr. Bones of animals under 100 kg and juveniles appear to weather more rapidly than bones of large animals or adults. Small-scale rather than widespread environmental factors seem to have greatest influence on weathering characteristics and rates. Bone weathering is potentially valuable as evidence for the period of time represented in recent or fossil bone assemblages, in- cluding those on archeological sites, and may also be an important tool in censusing populations of animals in modern ecosystems.

Taphonomic and Ecologic Information Form Bone Weathering

The conditions for the self-organized formation of ordered hexagonal structures in anodic alumina were investigated for both oxalic and sulfuric acid as an electrolyte. Highly ordered pore arrays were obtained for oxidation in both acids. The size of the ordered domains depends strongly on the anodizing voltage. This effect is correlated with a voltage dependence of the volume expansion of the aluminum during oxidation and the current efficiency for oxide formation. The resulting mechanical stress at the metal/oxide interface is proposed to cause repulsive forces between the neighboring pores which promote the formation of ordered hexagonal pore arrays.

/pdf/self-organized-formation-of-hexagonal-pore-arrays-in-anodic-izy2ovbidd.pdf

Self-organized formation of hexagonal pore arrays in anodic alumina

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans.

/pdf/the-simons-genome-diversity-project-300-genomes-from-142-2rh6yo9x6u.pdf

The Simons Genome Diversity Project: 300 genomes from 142 diverse populations

Strontium isotope analysis of archaeological skeletons has provided useful and exciting results in archaeology in the last 20 years, particularly by characterizing past human migration and mobility. This review covers the biogeochemical background, including the origin of strontium isotope compositions in rocks, weathering and hydrologic cycles that transport strontium, and biopurification of strontium from to soils, to plants, to animals and finally into the human skeleton, which is subject to diagenesis after burial. Spatial heterogeneity and mixing relations must often be accounted for, rather than simply ``matching'' a measured strontium isotope value to a presumed single-valued geologic source. The successes, limitations and future potential of the strontium isotope technique are illustrated through case studies from geochemistry, biogeochemistry, ecology and archaeology.

/pdf/strontium-isotopes-from-the-earth-to-the-archaeological-2c7rwbxe6b.pdf

Strontium Isotopes from the Earth to the Archaeological Skeleton: A Review

Time perspectives, palimpsests and the archaeology of time

Current fossil, genetic, and archeological data indicate that Homo sapiens originated in Africa in the late Middle Pleistocene. By the end of the Late Pleistocene, our species was distributed across every continent except Antarctica, setting the foundations for the subsequent demographic and cultural changes of the Holocene. The intervening processes remain intensely debated and a key theme in hominin evolutionary studies. We review archeological, fossil, environmental, and genetic data to evaluate the current state of knowledge on the dispersal of Homo sapiens out of Africa. The emerging picture of the dispersal process suggests dynamic behavioral variability, complex interactions between populations, and an intricate genetic and cultural legacy. This evolutionary and historical complexity challenges simple narratives and suggests that hybrid models and the testing of explicit hypotheses are required to understand the expansion of Homo sapiens into Eurasia.

/pdf/rethinking-the-dispersal-of-homo-sapiens-out-of-africa-53c7jybi8h.pdf

Rethinking the dispersal of Homo sapiens out of Africa.

The study of the proportions of stable isotopes of carbon and nitrogen which survive in ancient human and animal bones offers highly suggestive indications of ancient diets. Among the most remarkable results from such investigations is the dramatic change in diet which is thought to have occurred between the Mesolithic and the Neolithic when people turned from maritime to terrestrial
food, from fish to meat and vegetables. The three contributions which follow challenge, modify, enhance or reflect on this model. In a pivotal critique of the evidence from Britain and Denmark, Milner et al. present a range of explanations for the signals of a maritime or terrestrial emphasis in diet and conclude that the change need not have been either rapid or total. Liden et al. show that, in southern Sweden, the preferences for fish over meat were related less to period or culture, but (reasonably enough) to location: fish-eaters live by the sea. Finally Robert Hedges takes up the question of partial marine diets and how to detect them, developing the idea that marine diets might give a fainter signal in people who were only getting small amounts of protein. Perhaps there
were many such people in the new order of the Neolithic …

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0003598X00092887

Something fishy in the Neolithic? A re-evaluation of stable isotope analysis of Mesolithic and Neolithic coastal populations

Discussions of time in the archaeological literature have generally been dominated by problems of time measurement. Time concepts, however, have received little attention until recently (3, 11-13, 20, 38, 66, 72, 75, 80, 81, 93, 94, 97, 105, 114), even though they have been a longstanding source of interest to many other disciplines including philosophy, the natural and social sciences, history, and geography (1, 7, 15, 17, 18, 21, 33, 42, 43, 46, 48, 49, 52, 57, 87, 99, 110-112). To a large extent this is traceable to the difficulties of dating. It is only with the relatively recent development and widespread application of radiometric dating methods that archaeologists have begun to free themselves from technical preoccupations and to concentrate more fully on problems of process. Above all, new dating methods have demonstrated that human cultural history extends over a time span of at least two million years. This poses in a new way the issue of how we are to make use of knowledge about the past, what questions we should ask of it, and whether, by archaeological investigation of human activities over this time span, we can learn something new about human nature not available from other sources. I use the term quaternary prehistory here to emphasize an interest, in principle, in a time span of up to two million years. The effect of time concepts on archaeological interpretation can be considered from two points of view. The first examines their influence on the thinking of archaeologists in their interpretation of past behavior. The second examines their influence on the thinking and behavior of prehistoric people and hence on the patterns which contribute to the archaeological record. Contrasting notions of time are more or less implicit in archaeological thinking and have resulted in misguided rivalry between alternative approaches

Concepts of Time in Quaternary Prehistory

A number of charred surface residues, adhering to ceramic containers, were obtained from various coastal and inland sites in north-west Europe dating from the sixth to the fourth millennium cal bc. In order to investigate the use of these vessels and in particular to identify any marine products, the residues were subjected to carbon and nitrogen stable isotope analysis. Variation in carbon isotope ratios between different samples indicated that some vessels may have been used to process marine products. This analysis was corroborated by specific identification of aquatic products following structural and isotopic characterization of lipids extracted from selected samples.

Geoff Bailey

Papers

Time perspectives, palimpsests and the archaeology of time

Rethinking the dispersal of Homo sapiens out of Africa.

Something fishy in the Neolithic? A re-evaluation of stable isotope analysis of Mesolithic and Neolithic coastal populations

Concepts of Time in Quaternary Prehistory

Molecular and isotopic demonstration of the processing of aquatic products in northern European prehistoric pottery