Paleodemographic analysis of age at death for a population of Black Sea Scythians:: an exploration by using Bayesian methods
Paleodemographic analysis of age at death for a population of Black Sea Scythians:: an exploration by using Bayesian methods
Objectives: studies of the demography of past populations involving deterministic life tables can be criticised for ignoring the errors of estimation. Bayesian methods offer an alternative, by focusing on the uncertainty of the estimates, although their results are often sensitive to the choice of prior distributions. The aim of this study is to explore a range of Bayesian methods for estimating age at death for a population of nomadic warriors – Scythians from the Black Sea region.
Materials and Methods: in total, skeletons of 312 individuals (93 children and 219 adults) from Glinoe (Moldova), dated to the 5th-2nd c. BCE, were examined. We unified the age categories corresponding to different aging methods, allowing an application of a probabilistic assessment of the age categorisation. A hierarchical Bayesian multinomial-Dirichlet-Dirichlet model was applied, with a hypothetical, subjective reference population, a real reference population, and no reference.
Results: stationary-population life expectancy was estimated as 27.7 years (95% CI: 25.1–30.3) for a newborn (e0), and 16.4 years (14.0–19.0) for 20-year-olds (e20), although with high uncertainty, and sensitive to the model specification. Slight differences in longevity between different social strata and between the Classical and Late chronological periods were found, although with high estimation errors. A more robust finding, confirming earlier studies, was a high probability of death in young adulthood, which could depend on Scythian lifestyle (conflicts, wars).
Discussion: our study shows a way to overcome some limitations of broad age categorisation by using the Bayesian approach with alternative model specifications, allowing to assess the impact of reference populations.
Bayesian methods, Black Sea Scythians, age categorization, paleodemography, reference populations
595-613
Łukasik, Sylwia
b0b83bf6-dfcb-4b45-9201-cf9b7c88c7e8
Bijak, Jakub
e33bf9d3-fca6-405f-844c-4b2decf93c66
Krenz-Niedbała, Marta
387b2e14-c625-4d22-ad10-1780cc77b075
Sinika, Vitaly
22ec9a13-2eae-425e-9426-d5875cce7393
April 2021
Łukasik, Sylwia
b0b83bf6-dfcb-4b45-9201-cf9b7c88c7e8
Bijak, Jakub
e33bf9d3-fca6-405f-844c-4b2decf93c66
Krenz-Niedbała, Marta
387b2e14-c625-4d22-ad10-1780cc77b075
Sinika, Vitaly
22ec9a13-2eae-425e-9426-d5875cce7393
Łukasik, Sylwia, Bijak, Jakub, Krenz-Niedbała, Marta and Sinika, Vitaly
(2021)
Paleodemographic analysis of age at death for a population of Black Sea Scythians:: an exploration by using Bayesian methods.
American Journal of Physical Anthropology, 174 (4), .
(doi:10.1002/ajpa.24211).
Abstract
Objectives: studies of the demography of past populations involving deterministic life tables can be criticised for ignoring the errors of estimation. Bayesian methods offer an alternative, by focusing on the uncertainty of the estimates, although their results are often sensitive to the choice of prior distributions. The aim of this study is to explore a range of Bayesian methods for estimating age at death for a population of nomadic warriors – Scythians from the Black Sea region.
Materials and Methods: in total, skeletons of 312 individuals (93 children and 219 adults) from Glinoe (Moldova), dated to the 5th-2nd c. BCE, were examined. We unified the age categories corresponding to different aging methods, allowing an application of a probabilistic assessment of the age categorisation. A hierarchical Bayesian multinomial-Dirichlet-Dirichlet model was applied, with a hypothetical, subjective reference population, a real reference population, and no reference.
Results: stationary-population life expectancy was estimated as 27.7 years (95% CI: 25.1–30.3) for a newborn (e0), and 16.4 years (14.0–19.0) for 20-year-olds (e20), although with high uncertainty, and sensitive to the model specification. Slight differences in longevity between different social strata and between the Classical and Late chronological periods were found, although with high estimation errors. A more robust finding, confirming earlier studies, was a high probability of death in young adulthood, which could depend on Scythian lifestyle (conflicts, wars).
Discussion: our study shows a way to overcome some limitations of broad age categorisation by using the Bayesian approach with alternative model specifications, allowing to assess the impact of reference populations.
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Łukasik_et_al_Scythians_AJPA_accepted_version
- Accepted Manuscript
Text
Paleodemographic analysis
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Accepted/In Press date: 30 November 2020
e-pub ahead of print date: 31 December 2020
Published date: April 2021
Additional Information:
Funding Information:
A National Science Centre grant (NCN Miniatura 2017/01/X/HS3/00234) is gratefully acknowledged. The authors thank Henri Caussinus and Daniel Courgeau for a discussion about their method, and two AJPA reviewers for very helpful comments on earlier versions of the paper. All the remaining errors and inaccuracies are ours.
Publisher Copyright:
© 2020 Wiley Periodicals LLC
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
Keywords:
Bayesian methods, Black Sea Scythians, age categorization, paleodemography, reference populations
Identifiers
Local EPrints ID: 446648
URI: http://eprints.soton.ac.uk/id/eprint/446648
ISSN: 0002-9483
PURE UUID: c98fe00c-9abc-4c3b-b2f8-084ab068c448
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Date deposited: 17 Feb 2021 17:30
Last modified: 17 Mar 2024 03:18
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Author:
Sylwia Łukasik
Author:
Marta Krenz-Niedbała
Author:
Vitaly Sinika
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