DOI: 10.5061/dryad.crjdfn3f7
title: Implications of the last glacial maximum on the genetic diversity of six co-distributed taxa in the Baja California Peninsula

description: Aim: During the Last Glacial Maximum, the temperature in the Baja
 California Peninsula decreased and the precipitation increased compared to
 present climatic conditions. These changes influenced the geographic
 distribution and the demographic processes of plants and animals. This
 article aims to determine how Pleistocene and current climate impacted the
 geographic distribution and the genetic diversity patterns of six species
 co-distributed in the Baja California Peninsula. Location: Northwest
 Mexico. Taxon: A group of six species with desert affinities, two cacti (
 Pachycereus pringlei and Stenocereus gummosus), one spider ( Pardosa
 sierra), one reptile ( Dipsosaurus dorsalis) and two birds ( Melanerpes
 uropygialis and Basilinna xantusii). Methods: Meta-analysis of published
 microsatellite data was carried out for the previously mentioned species.
 Hierarchical Generalized Additive Models (HGAMs) were used to assess the
 relationship between genetic diversity values and six abiotic predictors
 (latitude, elevation, current climate, habitat suitability, climatic
 stability, and habitat suitability stability from the Last Glacial Maximum
 to the present). The change in the distribution range from the Last
 Glacial Maximum to the present was found using Potential Distribution
 Models (PDMs). Results: HGAMs revealed that Melanerpes
 uropygialis showed a significant relationship between genetic diversity
 and climatic stability, while the genetic diversity of Dipsosaurus
 dorsalis responded to the current climate. The genetic diversity of
 Melanerpes uropygialis and Pachycereus pringlei was affected by habitat
 suitability change while in Basilinna xantusii, genetic diversity changed
 with current habitat suitability. According to potential distribution
 models, four areas of northwest Mexico functioned as a refuge during the
 Last Glacial Maximum: the south of the peninsula, the region between the
 western tip of the Vizcaíno peninsula and Cedros Island, the upper Gulf of
 California and the coasts of Sonora. However, only the spatial patterns of
 predicted genetic diversity of Melanerpes uropygialis coincide with the
 location of Pleistocene refugia. Main conclusions: No evidence was found
 of a concerted response of species to climate change during the
 Pleistocene, only one species showed evidence of discrete Pleistocene
 refugia, and climatic stability and habitat suitability are not always
 conducive to higher genetic diversity values.
description: <strong>Gam_data: </strong>Expected heterozygosity
 corrected for the number of samples (<em>He</em>) was
 determined in GenAlEx version 6.5 (Peakall & Smouse, 2006).
 Allelic richness (<em>Ar</em>) was calculated in the R package
 hierfstat (Goudet, 2005) and the rarefaction method was applied to avoid
 biases due to differences in the number of samples (the sample size was
 adjusted to two in all species). Latitude and longitude were retrieved
 from the coordinates of each locality. Elevation data were obtained from
 the NASADEM Digital Elevation Model (NASA JPL, 2020). Current climate data
 (B1, B5, and B12) were obtained from the 19 climate layers of WorldClimm
 2.1 (Fick & Hijmans, 2017) while for climate change data (the
 absolute difference between current and Last Glacial Maximum climatic
 variables; B1_c, B5_c, B6_c, and B12_c) the Last Glacial Maximum climate
 data was obtained by averaging the raster of the three global circulation
 models available in WorldClimm 1.4 (Hijmans et al., 2005), the Community
 Climate System Model (CCSM4; Gent et al., 2011), the Model for
 Interdisciplinary Research on Climate (MIROC-ESM; Hasumi & Emori,
 2004) and the Max Planck Institute for Meteorology Earth System Model
 (MPI-ESM-P; Giorgetta et al., 2013). Habitat suitability (HS) and habitat
 suitability stability (HS_c) values were obtained from Potential
 Distribution Models.
 <strong>Species_OccurrenceData:</strong> Occurrence
 records for <em>P. pringlei (Pp) </em>and <em>P. sierra
 (Ps) </em>were obtained from previous work (González-Trujillo et
 al., 2016; Gutiérrez-Flores et al., 2016). For <em>B. xantusii (Bx)
 </em>were obtained from the geographic metadata catalog of the
 Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO;
 Navarro-Sigüenza et al., 2018). <em>S. gummosus (Sg), D. dorsalis
 (Dd) </em>and<em> M. uropygialis (Mu) </em>occurrence
 records were obtained from the Global Biodiversity Information Facility
 (GBIF; GBIF.org, 2022, 2024a, 2024b).
description: # Implications of the last glacial maximum on the genetic diversity of six
 co-distributed taxa in the Baja California Peninsula
 [https://doi.org/10.5061/dryad.crjdfn3f7](https://doi.org/10.5061/dryad.crjdfn3f7) ## Description of the data and file structure GAM_data: contains the data used for the generalized additive model, which was used to find the relationship between two metrics of genetic diversity (expected heterozygosity and allelic richness) and several abiotic predictors. Bx_OccurrenceData: contains the coordinates of the Basilinna xantusii occurrence points used for the potential distribution model. Dd_OccurrenceData: contains the coordinates of the Dipsosaurus dorsalis occurrence points used for the potential distribution model. Mu_OccurrenceData: contains the coordinates of the Melanerpes uropygialis occurrence points used for the potential distribution model. Pp_OccurrenceData: contains the coordinates of the Pachycereus pringlei occurrence points used for the potential distribution model. Ps_OccurrenceData: contains the coordinates of the Pardosa sierra occurrence points used for the potential distribution model. Sg_OccurrenceData: contains the coordinates of the Stenocereus gummosus occurrence points used for the potential distribution model. ### Files and variables #### File: Bx\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees #### File: Ps\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees #### File: Pp\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees #### File: GAM\_data.csv **Description:**  ##### Variables * Species: Species * L: Locality * n: number of samples * Lat: Latitude degrees * Lon: Longitude degrees * He: Expected heterozygosity  * Ar: Allelic richness * E: Elevation (Metres above sea level; m a.s.l) * B1_c: absolute difference in annual mean temperature between present and Last Glacial Maximum (Degree Celsius; °C) * B5_c: absolute difference in maximum temperature of warmest month between present and Last Glacial Maximum (Degree Celsius; °C) * B6_c:  absolute difference in minimum temperature of coldest month between present and Last Glacial Maximum (Degree Celsius; °C) * B12_c: absolute difference in annual precipitation between the present and the Last Glacial Maximum (Millimeter; mm) * B1: annual mean temperature (Degree Celsius; °C) * B5: maximum temperature of current warmest month (Degree Celsius; °C) * B12: annual precipitation (Millimeter; mm) * HS_p: habitat suitability * HS_c: absolute difference in habitat suitability between present and Last Glacial Maximum #### File: Sg\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees #### File: Dd\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees #### File: Mu\_OccurrenceData.csv **Description:**  ##### Variables * Species: Species * Longitude: Longitude degrees * Latitude: Latitude degrees