Comparing Genetic Variation among Latin American Immigrants: Implications for Forensic Casework in the Arizona- and Texas-Mexico Borderlands

Document Type

Article

Authors

Briana T. New, SNA International supporting the Defense POW/MIA Accounting AgencyFollow
Bridget F.B. Algee-Hewitt, Stanford University
M. Katherine Spradley, Anthropology Department, Texas State University
Lars Fehren-Schmitz, UCSC Genomics Institute, Anthropology Department, University of California, Santa Cruz
Cris E. Hughes, Anthropology Department, University of Illinois, Urbana-Champaign
Bruce E. Anderson, Pima County Office of the Medical Examiner
Marek E. Jasinski, Department of Historical and Classical Studies, NTNU Norwegian University of Science and Technology and Falstad Center
Joanna Arciszewska, Department of Forensic Genetics, Pomeranian Medical University in Szczecin
Grażyna Zielińska, Department of Forensic Genetics, Pomeranian Medical University in Szczecin
Maria Szargut, Department of Forensic Genetics, Pomeranian Medical University in Szczecin
Sandra Cytacka, Department of Forensic Genetics, Pomeranian Medical University in Szczecin
Andrzej Ossowski, Department of Forensic Genetics, Pomeranian Medical University in Szczecin

Abstract

The humanitarian crisis on the US-Mexico border is a long-standing and evolving crisis in which nearly 8,000 deaths have been reported in the last two decades. These deaths are largely distributed across the Arizona-Mexico and Texas-Mexico border regions, where demographic trends for immigrants attempting to cross into the United States have shifted dramatically. The demographic change and volume of immigrants seeking shelter in the United States present new challenges for the forensic practitioners entrusted with the identification of individuals who lose their lives during the final segment of their journey. Within this border context, this study investigated how genetic variation inferred from forensically significant microsatellites can provide valuable information on regions of origin for unidentified remains at the group level. To explore how to mobilize these genetic data to inform identification strategies, the authors conducted a comparative genetic analysis of identified and unidentified immigrant cases from the Arizona- and Texas-Mexico contexts, as well as 27 other Latin American groups. Allele frequencies were utilized to calculate F_ST, and relationships were visually depicted in a multidimensional scaling plot. A Spearman correlation coefficient analysis assessed the strength and significance of population relationships, and an agglomerative clustering analysis assessed population clusters. Results indicate that Arizona-Mexico immigrants have the strongest relationship (>80%) with groups from El Salvador, Guatemala, Mexico, and an indigenous group from southern Mexico. Texas-Mexico immigrants have the strongest relationships (>80%) with groups from Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua. These findings agree with, and are discussed in comparison with, previously reported demographic trends, population genetics research, and population history analyses. The authors emphasize the utility and necessity of coupling genetic variation research with a nuanced anthropological perspective for identification processes in the US-Mexico border context.

Recommended Citation

New, Briana T.; Algee-Hewitt, Bridget F.B.; Spradley, M. Katherine; Fehren-Schmitz, Lars; Hughes, Cris E.; Anderson, Bruce E.; Jasinski, Marek E.; Arciszewska, Joanna; Zielińska, Grażyna; Szargut, Maria; Cytacka, Sandra; and Ossowski, Andrzej (2021) "Comparing Genetic Variation among Latin American Immigrants: Implications for Forensic Casework in the Arizona- and Texas-Mexico Borderlands," Human Biology: Vol. 93: Iss. 1, Article 3.
Available at: https://digitalcommons.wayne.edu/humbiol/vol93/iss1/3