Clovis point allometry, modularity, and integration: Exploring shape variation due to tool use with landmark-based geometric morphometrics.

Landmark-based geometric morphometrics (LGM) is most often used in archaeology to characterize and differentiate groups of artifacts, but it can be used for much more. We demonstrate LGM's power to uncover new insights by exploring stone-tool allometry, modularity, and integration using a sample of 100 western North American Clovis points. Here, allometry concerns how stone tools change in shape as their size changes through their use-lives, and modularity and integration concern how the constituent parts of a tool work together. We show that Clovis points are surprisingly complex tools. When their blades and hafts are defined technologically, rather than arbitrarily, they unambiguously exhibit allometry, and their hafts and blades are modular and highly integrated. We use these analyses to further explore questions about Clovis points, including the differences between cache and non-cache points. Finally, we use heuristic haft-size categories to examine functional constraints on the shape and size of hafts and blades. This work illustrates the importance of using accurate measurements of point components rather than estimates or proxies, which can lead to unfounded inferences. These analytical approaches and accompanying R code are easily transferable to other research questions of stone-tool use.

Merit and placement in the American faculty hierarchy: Cumulative advantage in archaeology.

If faculty placement in the American academic hierarchy is by merit, then it correlates with scholarly productivity at all career stages. Recently developed data-collection methods and bibliometric measures test this proposition in a cross-sectional sample of US academic archaeologists. Precocity-productivity near the point of initial hire-fails to distinguish faculty in MA- and PhD-granting programs or among ranked subsets of PhD programs. Over longer careers, on average archaeologists in PhD-granting programs outperform colleagues in lower programs, as do those in higher-ranked compared to lower-ranked PhD programs, all in the practical absence of mobility via recruitment to higher placement. Yet differences by program level lie mostly in the tails of productivity distributions; overlap between program levels is high, and many in lower-degree programs outperform many PhD-program faculty even when controlling for career length. Results implicate cumulative advantage to explain the pattern and suggest particularism as its cause.

Stage and continuum approaches in prehistoric biface production: A North American perspective.

North American lithic analysis often assigns biface preforms to discrete, successive stages defined in Callahan's influential study. Yet recent research questions the stage concept, emphasizing instead a continuous view of the reduction process. To compare stage and continuum approaches, their assumptions are tested in experimental replicas, including Callahan's, and empirical Paleoindian preform assemblages. In these samples, biface reduction is a process that can be tracked and measured by continuous measures of size and reduction allometry. The process is characterized by continuous variation in the rate at which preform weight declines with preform volume. That is, weight declines at an ever-declining rate through the production process. Reduction is complex, but understood better as an allometric process than as a sequence of technological stages. "Stage" may be a useful heuristic or summary device, but preform assemblages should be analyzed in detail to reveal the continuous allometric processes that govern biface production.