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13-7 Do life-history traits explain phylogeographic discordance in the Baja California Peninsula?

Session: Earth Life Sciences across the Cordillera

Presenting Author:

Anayeli Márquez

Authors:

Márquez, Anayeli¹, Landguth, Erin², Day, Casey³, García de León, Francisco Javier⁴

(1) Laboratorio de Genética para la conservación, Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, Mexico, (2) Computational Ecology Laboratory, University of Montana, Missoula, Montana, USA, (3) Computational Ecology Laboratory, University of Montana, Missoula, Montana, USA, (4) Laboratorio de Genética para la Conservación, Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, Mexico,

Abstract:

Comparative phylogeography has revealed how shared geographic and climatic histories shape genetic structure of co-distributed species. However, phylogeographic discordance is common even among taxa exposed to the same historical events and is often attributed, post hoc, to species-specific life-history differences. In this study, we explicitly assessed the role of life-history traits in generating concordant and discordant phylogeographic patterns using a spatially explicit demogenetic simulation framework.

We simulated 72 virtual species spanning a broad life-history continuum, with variation in vital rates, dispersal capacity, and population size. The species were subjected to two contrasting biogeographic scenarios in the Baja California Peninsula: (1) isolation by distance and (2) a transient vicariant barrier in the mid-peninsula. By tracking the temporal dynamics of genetic differentiation (Fst), we quantified how individual traits influence the accumulation of divergence and the persistence of genetic signatures after barrier removal.

Our results show that dispersal capacity and population size explain most of the variance in genetic differentiation. Population size impacts the divergence accumulation during vicariance and peak differentiation, whereas dispersal governs post-barrier decay rates. Vital rates contribute less, but consistently, to the explained variation. Overall, our findings highlight that phylogeographic discordance emerges from context-dependent and non-additive interactions among traits, with dispersal limitation and demographic constraints outweighing intrinsic life-history syndromes. This work provides a theoretical benchmark for interpreting (dis)concordance in comparative phylogeographic studies.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3, 2026

Do life-history traits explain phylogeographic discordance in the Baja California Peninsula?

Description

Session Format: Oral

Presentation Date: 4/22/2026

Presentation Start Time: 03:30 PM

Presentation Room: LMH, Fiesta Terrace Salon

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