Hominin reliance on Oldowan stone tools—which appear from 2.5 mya and are believed to have been socially transmitted—has been hypothesized to have led to the evolution of teaching and language. Here we present an experiment investigating the efficacy of transmission of Oldowan tool-making skills along chains of adult human participants (N ¼ 184) using five different transmission mechanisms. Across six measures, transmission improves with teaching, and particularly with language, but not with imitation or emulation. Our results support the hypothesis that hominin reliance on stone tool-making generated selection for teaching and language, and imply that (i) low-fidelity social transmission, such as imitation/emulation, may have contributed to the B700,000 year stasis of the Oldowan technocomplex, and (ii) teaching or proto-language may have been pre-requisites for the appearance of Acheulean technology. This work supports a gradual evolution of language, with simple symbolic communication preceding behavioural modernity by hundreds of thousands of years.

/pdf/experimental-evidence-for-the-co-evolution-of-hominin-tool-b20lx2igtz.pdf

Experimental evidence for the co-evolution of hominin tool-making teaching and language

Animal Tool Behavior: The Use and Manufacture of Tools by Animals, Benjamin B. Beck. Garland STPM Press, New York and London (1980), 306, Price £24.50

For many years, intuition and common sense often guided the transference of patterning ostensibly evident in experimental flintknapping results to interpretations of the archaeological record, with little emphasis placed on hypothesis testing, experimental variables, experimental design, or statistical analysis of data. Today, archaeologists routinely take steps to address these issues. We build on these modern efforts by reviewing several important uses of replication experiments: (1) as a means of testing a question, hypothesis, or assumption about certain parameters of stone-tool technology; (2) as a model, in which information from empirically documented situations is used to generate predictions; and (3) as a means of validating analytical methods. This review highlights the important strategic role that stone artifact replication experiments must continue to play in further developing a scientific approach to archaeology.

https://tandfonline.com/doi/pdf/10.1080/19442890.2016.1213972

Test, Model, and Method Validation: The Role of Experimental Stone Artifact Replication in Hypothesis-driven Archaeology

Background 
Middle Palaeolithic stone artefacts referred to as ‘Levallois’ have caused considerable debate regarding issues of technological predetermination, cognition and linguistic capacities in extinct hominins. Their association with both Neanderthals and early modern humans has, in particular, fuelled such debate. Yet, controversy exists regarding the extent of ‘predetermination’ and ‘standardization’ in so-called ‘preferential Levallois flakes’ (PLFs).


Methodology/Principal Findings 
Using an experimental and morphometric approach, we assess the degree of standardization in PLFs compared to the flakes produced during their manufacture. PLFs possess specific properties that unite them robustly as a group or ‘category’ of flake. The properties that do so, relate most strongly to relative flake thicknesses across their surface area. PLFs also exhibit significantly less variability than the flakes generated during their production. Again, this is most evident in flake thickness variables. A further aim of our study was to assess whether the particular PLF attributes identified during our analyses can be related to current knowledge regarding flake functionality and utility.


Conclusions/Significance 
PLFs are standardized in such a manner that they may be considered ‘predetermined’ with regard to a specific set of properties that distinguishes them statistically from a majority of other flakes. Moreover, their attributes can be linked to factors that, based on current knowledge, are desirable features in flake tools (e.g. durability, capacity for retouch, and reduction of torque). As such, our results support the hypothesis that the lengthy, multi-phase, and hierarchically organized process of Levallois reduction was a deliberate, engineered strategy orientated toward specific goals. In turn, our results support suggestions that Levallois knapping relied on a cognitive capacity for long-term working memory. This is consistent with recent evidence suggesting that cognitive distinctions between later Pleistocene hominins such as the Neanderthals and anatomically modern humans were not as sharp as some scholars have previously suggested.

/pdf/why-levallois-a-morphometric-comparison-of-experimental-f231az29em.pdf

Why Levallois? A Morphometric Comparison of Experimental ‘Preferential’ Levallois Flakes versus Debitage Flakes

Part I. Retrospectives and Theoretical Perspectives 1. Early humans: of whom do we speak? Richard E. Leakey 2. Homo habilis - a premature discovery: remembered by one of its founding fathers, 42 years later Phillip V. Tobia 3. Where does the genus Homo begin, and how would we know? Bernard Wood Part II. Craniodental Perspectives on Taxonomy and Systematics 4. The origin of Homo William H. Kimbel 5. Comparisons of Early Pleistocene skulls from East Africa and the Georgian Caucasus: evidence bearing on the origin and systematics of genus Homo G. Philip Rightmire and David Lordkipanidze 6. Phenetic affinities of Plio-Pleistocene Homo fossils from South Africa: molar cusp proportions Frederick E. Grine, Heather F. Smith, Christopher P. Heesy and Emma J. Smith Part III. Postcranial Perspectives on Locomotion and Adaptation 7. Evolution of the hominin shoulder: early Homo Susan G. Larson 8. Brains, brawn, and the evolution of human endurance running capabilities Daniel E. Lieberman, Dennis M. Bramble, David A. Raichlen and John J. Shea 9. Interlimb proportions in humans and fossil hominins: variability and scaling William L. Jungers Part IV. Perspectives on Development, Diet and Behavior 10. Growth and development of the Nariokotome youth, KNM-WT 15000 M. Christopher Dean and B. Holly Smith 11. Dental evidence for diets of early Homo Peter S. Ungar and Robert S. Scott 12. Origins and adaptations of early Homo: what archaeology tells us Helene Roche, Robert J. Blumenschine and John J. Shea Part V. Environmental and Ecological Perspectives 13. Plio-Pleistocene EastAfrican pulsed climate variability and its influence on early human evolution. Mark A. Maslin and Martin H. Trauth 14. Tracking ecological change in relation to the emergence of Homo near the Plio-Pleistocene boundary. Kaye E. Reed and Samantha M. Russak 15. Ecology of Plio-Pleistocene mammals in the Omo-Turkana Basin and the emergence of Homo. Rene Bobe and Meave G. Leakey 16. Biogeochemical evidence for the environments of early Homo in South Africa Matt Sponheimer and Julia Lee-Thorp Part VI. Summary Perspective on the Workshop 17. The first humans: a summary perspective on the origin and early evolution of the genus Homo. Frederick E. Grine and John G. Fleagle

The first humans : origin and early evolution of the genus Homo : contributions from the third Stony Brook Human Evolution Symposium and Workshop, October 3-October 7, 2006

Are bigger flakes always better? An experimental assessment of flake size variation on cutting efficiency and loading

Simple flake cutting tools were utilized across broad chronological and geographical ranges during prehistory. Fundamental to their functional utility is the presence of a relatively acute working edge. The acuteness of this ‘edge angle’ is widely hypothesized to be a primary determinant of cutting efficiency and, subsequently, of potential consequence to prehistoric peoples. However, the influence of the cutting edge angle in flake tools on the ability (efficiency) of tool users to cut through objects has not been empirically investigated under explicitly stated experimental conditions. Moreover, no consideration has been given to whether this relationship is dependent upon the size of the tool. Here, the influence that edge angle exerts on human stone tool users is examined experimentally in terms of efficiency during a cutting task, while also considering the relationship between edge angle, loading (i.e., the force applied) and overall flake size. The results demonstrate that there is a highly significant relationship between more acute working edges and increased cutting efficiency in the smallest flake tools tested. Above a certain flake-size threshold, however, the working edge angle has no influence on cutting efficiency because larger flakes appear to facilitate the application of greater working loads by tool users. These results have important implications for potential flake selection criteria by prehistoric peoples, especially in relation to utility, function and the changing effects of edge angle through a sequence of retouch.

Edge Angle as a Variably Influential Factor in Flake Cutting Efficiency: An Experimental Investigation of Its Relationship with Tool Size and Loading

Handaxes represent one of the most temporally enduring and geographically widespread of Palaeolithic artifacts and thus comprised a key technological strategy of many hominin populations. Archaeologically observable variation in the size (i.e., mass) and shape properties of handaxes has been frequently noted. It is logical to ask whether some of this variability may have had functional implications. Here, we report the results of a large-scale (n = 500 handaxes) experiment designed to examine the influence of variation in handaxe size and shape on cutting efficiency rates during a laboratory task. We used a comprehensive dataset of morphometric (size-adjusted) shape variables and statistical methods (including multivariate methods) to address this issue. Our first set of analyses focused on handaxe mass/size variability. This analysis demonstrated that, at a broad-scale level of variation, handaxe mass may have been free to vary independently of functional (cutting) efficiency. Our analysis also, however, identified that there will be a task-specific threshold in terms of functional effectiveness at the lower end of handaxe mass variation. This implies that hominins may have targeted design forms to meet minimal (task-specific) thresholds and may also have managed handaxe reduction and discard in respect to such factors. Our second set of analyses focused on handaxe shape variability. This analysis also indicated that considerable variation in handaxe shape may occur independently of any strong effect on cutting efficiency. We discuss how these results have several implications for considerations of handaxe variation in the archaeological record. At a general level, our results demonstrate that variability within and between handaxe assemblages in terms of their size and shape properties will not necessarily have had immediate or strong impact on their effectiveness when used for cutting, and that such variability may have been related to factors other than functional issues.

/pdf/influence-of-handaxe-size-and-shape-on-cutting-efficiency-a-47c7u9i3er.pdf

Influence of Handaxe Size and Shape on Cutting Efficiency: A Large-Scale Experiment and Morphometric Analysis

The evolution of the hominin thumb and the influence exerted by the non-dominant hand during stone tool production

Percussively flaked stone artefacts constitute a major source of evidence relating to hominin behavioural strategies and are, essentially, a product or byproduct of a past individual’s decision to create a tool with respect to some broader goal. Moreover, it has long been noted that both differences and recurrent regularities exist within and between Palaeolithic stone artefact forms. Accordingly, archaeologists have frequently drawn links between form and functionality, with functional objectives and performance often being regarded consequential to a stone tool’s morphological properties. Despite these factors, extensive reviews of the related concepts of form and function with respect to the Lower Palaeolithic remain surprisingly sparse. We attempt to redress this issue. First we stress the historical place of form–function concepts, and their role in establishing basic ideas that echo to this day. We then highlight methodological and conceptual progress in determining artefactual function in more recent years. Thereafter, we evaluate four specific issues that are of direct consequence for evaluating the ongoing relevance of form–function concepts, especially with respect to their relevance for understanding human evolution more generally. Our discussion highlights specifically how recent developments have been able to build on a long historical legacy, and demonstrate that direct, indirect, experimental, and evolutionary perspectives intersect in crucial ways, with each providing specific but essential insights for ongoing questions. We conclude by emphasising that our understanding of these issues and their interaction, has been, and will be, essential to accurately interpret the Lower Palaeolithic archaeological record, tool-form related behaviours of Lower Palaeolithic hominins, and their consequences for (and relationship to) wider questions of human evolution.

Alastair J.M. Key

Papers

Are bigger flakes always better? An experimental assessment of flake size variation on cutting efficiency and loading

Edge Angle as a Variably Influential Factor in Flake Cutting Efficiency: An Experimental Investigation of Its Relationship with Tool Size and Loading

Influence of Handaxe Size and Shape on Cutting Efficiency: A Large-Scale Experiment and Morphometric Analysis

The evolution of the hominin thumb and the influence exerted by the non-dominant hand during stone tool production

Form and function in the Lower Palaeolithic: history, progress, and continued relevance.