The humanitarian crisis on the United States-México 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-México and Texas-México border regions where demographic trends for immigrants attempting to cross into the U.S. have shifted dramatically. The demographic change and volume of immigrants seeking shelter in the U.S. presents 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, the present study investigates how genetic variation inferred from forensically significant microsatellites can provide valuable information on regions of origin for unidentified remains on the group level. To explore how we can mobilize these genetic data to inform identification strategies, we conduct a comparative genetic analysis of identified and unidentified immigrant cases from the Arizona- and Texas-México contexts, as well as 27 other Latin American groups. Allele frequencies were utilized to calculate FST, 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-México immigrants have the strongest relationship (>80%) with groups from El Salvador, Guatemala, México, and an indigenous group from Southern México. Texas-México 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 to, previously reported demographic trends, population genetics research, and population history analyses. We emphasize the utility and necessity of coupling genetic variation research with a nuanced anthropological perspective for identification processes in the U.S-México border context.
New, Briana T.; Algee-Hewitt, Bridget F.B.; Spradley, M. Katherine; Fehren-Schmitz, Lars; Hughes, Cris C.; Anderson, Bruce E.; Jasinski, Marek E.; Arciszewska, Joanna; Zielińska, Grażyna; Szargut, Maria; Cytacka, Sandra; and Ossowski, Andrzej, "Comparing Genetic Variation among Latin American Immigrants: Implications for Forensic Casework in the Arizona- and Texas-México Borderlands" (2021). Human Biology Open Access Pre-Prints. 191.