More Like this

1. Comparative Phylogeography of Phrynosomatid Lizards in Baja California: Asynchronous Divergences and Expansion of Callisaurus draconoides Across the North American Deserts

   https://doi.org/10.1111/jbi.70075  

   Gottscho, Andrew D; Hollingsworth, Bradford D; Espinal, Julio Lemos; Leaché, Adam D; Reeder, Tod W; de_Queiroz, Kevin (October 2025, Journal of Biogeography)

   ABSTRACT AimWe tested whether co‐distributed phrynosomatid lizards in the Baja California Peninsula (BCP) share synchronous phylogeographic discontinuities, as predicted by the “peninsular archipelago” hypothesis, and examined the diversification ofCallisaurus draconoidesthroughout its range. LocationThe BCP and the Great Basin, Mojave and Sonoran Deserts of southwestern North America. TaxaFive co‐distributed species complexes representing four genera within Phrynosomatidae:Callisaurus,Petrosaurus,UrosaurusandSceloporus. MethodsDouble‐digest restriction‐associated‐DNA (ddRAD) sequencing was used to collect genome‐wide sequence data for 309 lizards. We used phylogenetic analyses of concatenated loci and population admixture analysis of unlinked SNPs to identify lineages. To infer a species tree, we collected target sequence capture (TSC) data. Migration between adjacent peninsular lineages was estimated using the multispecies coalescent with migration (MSC‐M) in BPP. A full‐likelihood Bayesian comparative phylogeographic approach (ecoevolity) was used to test the simultaneous divergence hypothesis for the Isthmus of La Paz and Vizcaíno Desert. ResultsWe identified 24 potential lineages within the five co‐distributed complexes. Contact zones between lineages were observed at the Isthmus of La Paz in four of the five complexes, and in all five within the Vizcaíno Desert. The time‐calibrated species tree indicates that within each complex, divergences at the Isthmus of La Paz predate those across the Vizcaíno Desert. We found strong support for at least three independent divergence events at the Isthmus of La Paz and the Vizcaíno Desert, thereby rejecting the simultaneous divergence hypothesis. Inferred migration rates between adjacent peninsular populations were generally low (M << 1) to absent. Zebra‐tailed lizards (Callisaurus), in which the earliest diverging lineages are endemic to the southern BCP, exhibit a clear pattern of Pleistocene range expansion from the BCP into the deserts of the western United States and mainland Mexico. The most deeply nested populations inCallisaurusoccur at the northern, eastern and southeastern range limits in temperate, subtropical and tropical biomes, respectively. Main ConclusionsThese results support the BCP's tectonic isolation as a driver of peninsular endemism and a contributing factor to lineage diversification more broadly in the region. Taxonomic adjustments, including resurrectingUrosaurus microscutatus, are proposed to better reflect evolutionary history in taxonomy. 

   more » « less
2. Phylogenomics Reveal the Historical Biogeography and Multiple Transcontinental Dispersals of the Amphitropical Harvester Ant Genus Pogonomyrmex

   https://doi.org/10.1111/jbi.70236  

   Graber, Leland C; Johnson, Robert A; Moreau, Corrie S (May 2026, Journal of Biogeography)

   ABSTRACT AimThe harvester ant genusPogonomyrmexhas an amphitropical desert distribution, with high species diversity in arid regions of North America, South America and Hispaniola, and low species diversity in mesic regions. Here, we examine the historical biogeography ofPogonomyrmexto understand how the genus established its current distribution, with a focus on the origins of its amphitropical desert distribution and its spread to Hispaniola. LocationNorth America, South America and Hispaniola. MethodsWe inferred a new phylogeny ofPogonomyrmexusing ultraconserved elements (UCEs); we included duplicate samples of several species to test for species monophyly and evolutionary relationships within the genus. We used this phylogeny and geographic range data of extantPogonomyrmexto reconstruct the ancestral ranges and transcontinental dispersals of the genus. Additionally, we used a time‐stratified ancestral range reconstruction to test ifPogonomyrmexmay have utilized the hypothesized GAARlandia land bridge for dispersals to Hispaniola and North America. ResultsOur ancestral range reconstruction infers that the last common ancestor ofPogonomyrmexlived in northern South America during the middle Eocene. We infer thatPogonomyrmexdispersed from South America to North America twice, first in the Eocene and again in the Eocene or Oligocene. Results of our time‐stratified ancestral range reconstruction suggested thatPogonomyrmexdid not disperse over the GAARlandia land bridge; we instead infer thatPogonomyrmexdispersed over the Central American Seaway to North America on both occasions and was potentially aided by the pre‐isthmus Panama Arc. Further, we infer thatPogonomyrmexdispersed to Hispaniola from North America or Central America during the Oligocene or Miocene. Main ConclusionThis work adds to the growing body of literature that suggests that invertebrates were dispersing between North America and South America well before complete closure of the Isthmus of Panama, and that long‐distance dispersal played a significant role in the origins of desert biodiversity in North and South America. 

   more » « less
3. Phylogenomic analyses of the diverse desert–alpine plant lineage Cistantheae

   https://doi.org/10.1093/aob/mcaf319  

   Chomentowska, Anri; Dauerman, Sophie G; Heaphy, Nora M; Gaspar, Leonardo; Molina, Pablo M; Guilliams, C Matt; Ogburn, R Matthew; Hancock, Lillian P; Holtum, Joseph_A M; Moreira-Muñoz, Andrés; et al (December 2025, Annals of Botany)

   Abstract Background and AimsDesert and alpine environments, although ecologically distinct, often share similar environmental stressors, such as drought and high radiation. Various plant lineages traverse both biomes, which is often associated with transitions in life-history strategy, whereby annuality is more often associated with drier desert habitats and perenniality is more common in higher elevations. One such lineage is Cistantheae (Montiaceae), a morphologically diverse herbaceous clade in western North and South America. We aimed to infer a robust phylogeny of the clade as a foundation for taxonomic and comparative work. MethodsWe used double-digest restriction site-associated DNA sequencing to generate reduced-representation genomic data from >160 samples representing 48 putative species in Cistantheae. Maximum likelihood and coalescent-based phylogenetic methods were used to infer evolutionary relationships across the full clade and within major subclades. We tested for signatures of admixture and introgressive gene flow, and we reconstructed ancestral life history and climatic niche to identify patterns of correlated evolution. Key ResultsWe inferred a well-resolved phylogeny of Cistantheae, providing strong support for relationships among subclades within Cistantheae. Although many species relationships were clarified, we also found evidence of rampant gene flow and incomplete lineage sorting, particularly within the annual Cistanthe clade from the Atacama Desert. Life history is evolutionarily labile across the clade and strongly correlated with temperature and precipitation-related bioclimatic variables: annuals tend to occur in hotter and drier environments, whereas perennials tend to occur in cooler and wetter habitats. Elevational range is also evolutionarily labile, with several species occupying broad elevational gradients. ConclusionsWe present the first densely sampled phylogenomic analysis of Cistantheae, providing key insights into species relationships in the clade. Repeated transitions in life history and climatic niche, alongside wide elevational ranges, suggest that many Cistantheae species might be pre-adapted to both arid and montane habitats. This phylogeny will underpin further comparative, taxonomic and phylogenomic studies in this ecologically important lineage. 

   more » « less
4. Eight genome sequences of bacterial, environmental isolates from Canada Glacier, Antarctica

   https://doi.org/10.1128/mra.01130-23  

   Smith, Heidi J; Dieser, Markus; Foreman, Christine M (August 2024, Microbiology Resource Announcements)

   Maresca, Julia A (Ed.)

   ABSTRACT Sediments in cryoconite holes and meltwater streams in the McMurdo Dry Valleys, Antarctica, provide both substrates and conditions that support life in an arid polar desert. Here, we report the genomic sequences of eight environmental, bacterial isolates from Canada Glacier cryoconite holes and stream. These isolates span three major phyla. 

   more » « less
5. Characterizing the microbial metagenome of calcareous stromatolite formations in the San Felipe Creek in the Anza Borrego Desert

   https://doi.org/10.1128/mra.00881-23  

   Stancheva, Rosalina; Sethuraman, Arun; Khadivar, Hossein; Archambeau, Jenna; Caughran, Ella; Chang, Ashley; Hunter, Brad; Ihenyen, Christian; Onwukwe, Marvin; Palacios, Dariana; et al (April 2024, Microbiology Resource Announcements)

   Stewart, Frank J. (Ed.)

   ABSTRACT We describe the metagenome composition, community functional annotation, and prokaryote diversity in calcareous stromatolites from a dry stream bed of the San Felipe Creek in the Anza Borrego Desert. Analyses show a community capable of nitrogen fixation, assimilatory nitrate reduction, biofilm formation, quorum sensing, and potential thick-walled akinete formation for desiccation resistance. 

   more » « less