RT Journal Article T1 Importance of the Geographic Barriers to PromoteGene Drift and Avoid Pre- and Post-Col umbian GeneFlow in Mexican Native Groups: Evidence from Forensic STR Loci A1 Rangel Villalobos, Héctor A1 Martínez Sevilla, Victor Manuel A1 Martínez Cortés, Gabriela A1 Aguilar Velázquez, José Alonso A1 Sosa Macías, Martha A1 Rubí Castellanos, Rodrigo A1 González Martín, Antonio AB Objective: To analyze the origin, structure,relationships, and recent admixture in Mexican Native groups basedon 15 STRs commonly used in human identification.Methods: We analyzed 39 Mexican Native population samples using STR databases based on the AmpFlSTRVRIdentifiler kit (n=3,135), including Mexican-Mestizos (admixed),European and African populations, as reference.Results: Based upon effective population size (Ne) differences, Native groups were clustered into three regions: i)Center-Southeast groups, characterized by larger Ne, migration rate (Nm), genetic diversity (He), and relative homo-geneity principally in the Yucatan Peninsula; ii) Isolated southern groups from Chiapas and Oaxaca, characterizedby lower Ne, Nm, and He (i.e. higher isolation and genetic differentiation); iii) North-Northwest groups, which aresimilar to the previous group but are characterized by generating the widest gene flow barrier in the Pre-HispanicMexican territory, and currently by elevated admixture in some northern Native groups. Despite the relative congru-ence between genetic relationships with cultural, linguistic, geographic criteria, these factors do not explain thepresent-day population structure of Native groups, excepting in those linguistically related to the Mayan that showhigher homogeneity. The Isolation by distance model was demonstrated at long distances (>1,500 km), whereas geo-graphic isolation stands as a determining factor to avoid both non-indigenous admixture and bottleneck processes.Conclusions: Different dynamics of gene flow and drift were observed among Mexican Native groups, highlight-ing the geographic barriers (mountains, canyons and jungle regions) as the main factor differentiating Pre-hispanicpopulations, and eventually helping to avoid Post-European contact admixture and population bottleneck. PB John Wiley & Sons SN 0002-9483, ESSN: 1096-8644 YR 2016 FD 2016-06 LK https://hdl.handle.net/20.500.14352/23144 UL https://hdl.handle.net/20.500.14352/23144 LA eng NO CONACyT DS Docta Complutense RD 9 abr 2025