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Abstract
Inter-personal violence (whether intra- or inter-group) is a pervasive yet highly variable human behavior. Evolutionary anthropologists suggest that the abundance and distribution of resources play an important role in influencing differences in rates of violence, with implications for how resource conditions structure adaptive payoffs. Here, we assess whether differences in large-scale ecological conditions explain variability in levels of inter-personal human violence. Model results reveal a significant relationship between resource conditions and violence that is mediated by subsistence economy. Specifically, we find that interpersonal violence is highest: (1) among foragers and mixed forager/farmers (horticulturalists) in productive, homogeneous environments, and (2) among agriculturalists in unproductive, heterogeneous environments. We argue that the trend reversal between foragers and agriculturalists represents differing competitive pathways to enhanced reproductive success. These alternative pathways may be driven by features of subsistence (i.e., surplus, storage, mobility, privatization), in which foragers use violence to directly acquire fitness-linked social payoffs (i.e., status, mating opportunities, alliances), and agriculturalists use violence to acquire material resources that can be transformed into social payoffs. We suggest that as societies transition from immediate return economies (e.g., foragers) to delayed return economies (e.g., agriculturalists) material resources become an increasingly important adaptive payoff for inter-personal, especially inter-group, violence.
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Affiliation(s)
- Weston C. McCool
- Department of Anthropology, University of Utah, Salt Lake City, UT, United States of America
- Archaeological Center, University of Utah, Salt Lake City, UT, United States of America
- * E-mail:
| | - Kenneth B. Vernon
- Department of Anthropology, University of Utah, Salt Lake City, UT, United States of America
- Archaeological Center, University of Utah, Salt Lake City, UT, United States of America
- Global Change and Sustainability Center, Salt Lake City, UT, United States of America
| | - Peter M. Yaworsky
- Archaeological Center, University of Utah, Salt Lake City, UT, United States of America
- Department of Archaeology and Heritage Studies, Aarhus University, Aarhus, Denmark
| | - Brian F. Codding
- Department of Anthropology, University of Utah, Salt Lake City, UT, United States of America
- Archaeological Center, University of Utah, Salt Lake City, UT, United States of America
- Global Change and Sustainability Center, Salt Lake City, UT, United States of America
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Yaworsky PM, Vernon KB, Spangler JD, Brewer SC, Codding BF. Advancing predictive modeling in archaeology: An evaluation of regression and machine learning methods on the Grand Staircase-Escalante National Monument. PLoS One 2020; 15:e0239424. [PMID: 33002016 PMCID: PMC7529236 DOI: 10.1371/journal.pone.0239424] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 09/08/2020] [Indexed: 02/04/2023] Open
Abstract
Predictive models are central to both archaeological research and cultural resource management. Yet, archaeological applications of predictive models are often insufficient due to small training data sets, inadequate statistical techniques, and a lack of theoretical insight to explain the responses of past land use to predictor variables. Here we address these critiques and evaluate the predictive power of four statistical approaches widely used in ecological modeling-generalized linear models, generalized additive models, maximum entropy, and random forests-to predict the locations of Formative Period (2100-650 BP) archaeological sites in the Grand Staircase-Escalante National Monument. We assess each modeling approach using a threshold-independent measure, the area under the curve (AUC), and threshold-dependent measures, like the true skill statistic. We find that the majority of the modeling approaches struggle with archaeological datasets due to the frequent lack of true-absence locations, which violates model assumptions of generalized linear models, generalized additive models, and random forests, as well as measures of their predictive power (AUC). Maximum entropy is the only method tested here which is capable of utilizing pseudo-absence points (inferred absence data based on known presence data) and controlling for a non-representative sampling of the landscape, thus making maximum entropy the best modeling approach for common archaeological data when the goal is prediction. Regression-based approaches may be more applicable when prediction is not the goal, given their grounding in well-established statistical theory. Random forests, while the most powerful, is not applicable to archaeological data except in the rare case where true-absence data exist. Our results have significant implications for the application of predictive models by archaeologists for research and conservation purposes and highlight the importance of understanding model assumptions.
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Affiliation(s)
- Peter M Yaworsky
- Department of Anthropology, University of Utah, Salt Lake City, Utah, United States of America
- Archaeological Center, University of Utah, Salt Lake City, Utah, United States of America
- Global Change and Sustainability Center, Salt Lake City, Utah, United States of America
- Colorado Plateau Archaeological Alliance, Ogden, Utah, United States of America
| | - Kenneth B Vernon
- Department of Anthropology, University of Utah, Salt Lake City, Utah, United States of America
- Archaeological Center, University of Utah, Salt Lake City, Utah, United States of America
- Global Change and Sustainability Center, Salt Lake City, Utah, United States of America
| | - Jerry D Spangler
- Colorado Plateau Archaeological Alliance, Ogden, Utah, United States of America
| | - Simon C Brewer
- Global Change and Sustainability Center, Salt Lake City, Utah, United States of America
- Department of Geography, University of Utah, Salt Lake City, Utah, United States of America
| | - Brian F Codding
- Department of Anthropology, University of Utah, Salt Lake City, Utah, United States of America
- Archaeological Center, University of Utah, Salt Lake City, Utah, United States of America
- Global Change and Sustainability Center, Salt Lake City, Utah, United States of America
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3
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Macfarlan SJ, Schacht R, Foley C, Cahoon S, Osusky G, Vernon KB, Tayler E, Henrickson C, Schniter E. Marriage dynamics in old Lower California: ecological constraints and reproductive value in an arid peninsular frontier. Biodemography Soc Biol 2020; 65:156-171. [PMID: 32432937 DOI: 10.1080/19485565.2020.1728685] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
It is commonly expected that natural selection will favor earlier reproduction, yet ecological constraints can force people to delay marriage. Furthermore, humans demonstrate sex-specific preferences in marriage partners - with grooms normally a few years older than their brides; however, the age at which individuals marry can influence the spousal age gap. We investigate factors influencing age at first marriage and age difference at marriage using nineteenth-century historical demographic data from Baja California Sur, Mexico. Analyses suggest ecological constraints affected male, but not female, age at first marriage. Males who migrated from their natal community and who married in communities whose primary economic activity was agriculture experienced delayed age at first marriage. The age at which females first married increased over time causing a reduction in the age gap between spouses. Furthermore, the spousal age gap showed sex-specific effects: women who married early in life were much younger than their husbands, while women who married late in life were older than their husbands, suggesting that variation in female reproductive value influenced mate choice. Males, on the other hand, who married late in life showed a preference for marrying much younger females, indicating preferences for females with high reproductive value.
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Affiliation(s)
- Shane J Macfarlan
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
- Center for Latin American Studies, University of Utah, Salt Lake City, Utah, USA
- Global Change and Sustainability Center, University of Utah, Salt Lake City, Utah, USA
| | - Ryan Schacht
- Department of Anthropology, East Carolina University, Greenville, North Carolina, USA
| | - Caroline Foley
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Sydney Cahoon
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Grace Osusky
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Kenneth B Vernon
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Evan Tayler
- Department of Languages and Literature, University of Utah, Salt Lake City, Utah, USA
| | - Celeste Henrickson
- Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Eric Schniter
- Economic Science Institute, Chapman University, One University Drive, Orange, California, USA
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