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International Journal of Legal Medicine

, Volume 129, Issue 5, pp 1145–1153 | Cite as

AncesTrees: ancestry estimation with randomized decision trees

  • David NavegaEmail author
  • Catarina Coelho
  • Ricardo Vicente
  • Maria Teresa Ferreira
  • Sofia Wasterlain
  • Eugénia Cunha
Original Article

Abstract

In forensic anthropology, ancestry estimation is essential in establishing the individual biological profile. The aim of this study is to present a new program—AncesTrees—developed for assessing ancestry based on metric analysis. AncesTrees relies on a machine learning ensemble algorithm, random forest, to classify the human skull. In the ensemble learning paradigm, several models are generated and co-jointly used to arrive at the final decision. The random forest algorithm creates ensembles of decision trees classifiers, a non-linear and non-parametric classification technique. The database used in AncesTrees is composed by 23 craniometric variables from 1,734 individuals, representative of six major ancestral groups and selected from the Howells’ craniometric series. The program was tested in 128 adult crania from the following collections: the African slaves’ skeletal collection of Valle da Gafaria; the Medical School Skull Collection and the Identified Skeletal Collection of 21st Century, both curated at the University of Coimbra. The first step of the test analysis was to perform ancestry estimation including all the ancestral groups of the database. The second stage of our test analysis was to conduct ancestry estimation including only the European and the African ancestral groups. In the first test analysis, 75 % of the individuals of African ancestry and 79.2 % of the individuals of European ancestry were correctly identified. The model involving only African and European ancestral groups had a better performance: 93.8 % of all individuals were correctly classified. The obtained results show that AncesTrees can be a valuable tool in forensic anthropology.

Keywords

Forensic anthropology Ancestry estimation Howells’ craniometric series Random forest AncesTrees 

Notes

Acknowledgments

The authors thank Centro de Ciências Forenses and Centro de Investigação em Antropologia e Saúde. The authors also thank the anonymous reviewers for their comments and suggestions. The authors declare that they have no conflict of interest.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • David Navega
    • 1
    • 2
    Email author
  • Catarina Coelho
    • 2
  • Ricardo Vicente
    • 1
    • 2
  • Maria Teresa Ferreira
    • 1
    • 2
    • 3
  • Sofia Wasterlain
    • 1
    • 2
    • 3
  • Eugénia Cunha
    • 1
    • 2
    • 3
  1. 1.Forensic Sciences Centre (CENCIFOR)CoimbraPortugal
  2. 2.Department of Life Sciences, Faculty of Sciences and TechnologyUniversity of CoimbraCoimbraPortugal
  3. 3.Research Centre for Anthropology and Health (CIAS), Department of Life Sciences, Faculty of Sciences and TechnologyUniversity of CoimbraCoimbraPortugal

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