Document Type
Article
Publication Date
9-2024
ORCID
https://orcid.org/0000-0003-3402-5997
DOI
https://doi.org/10.1894/SWNAT-D-23-00038
Abstract
Mentzelia thompsonii is the only species in Mentzelia section Trachyphytum endemic to the Colorado Plateau and one of only a few that do not occur in California. In order to investigate the geographic origins, ecological function, and evolutionary potential of M. thompsonii and related species, we combine evidence from DNA, soil chemistry, and environmental niche modeling in a phylogenetic context. Based on ndhF–rpl32 cpDNA sequences from 185 specimens of M. thompsonii and 42 specimens representing the remaining 21 species in section Trachyphytum, we found that M. thompsonii is monophyletic and phylogenetically isolated from other species in Trachyphytum, suggesting that it is a paleoendemic. In contrast, the South American species, M. solierii, was placed sister to a haplotype from M. packardiae, representing the first published phylogenetic investigation of M. solierii. Soil analyses from all North American species in section Trachyphytum show that the edaphic niche of M. thompsonii is significantly different, and niche modeling with MaxEnt found that the distribution of Mancos Shale outcrops was five times more important than the most important climate variable for predicting the distribution of M. thompsonii. Surprisingly, subrange haplotype diversity in M. thompsonii did not match niche projections of climatic refugia during the last glacial maximum. Instead, diversity was lowest in the southernmost subrange and highest in the northernmost subrange of M. thompsonii. However, haplotype diversity was congruent with the projected distribution of M. thompsonii in 2081–2100, suggesting that genetic diversity in M. thompsonii has been shaped more by rapid warming and drought during interglacial periods than by the gradual cooling leading into glacial periods.
Recommended Citation
Brokaw, Joshua M.; Granados, Gracie M.; Browning, Logan A.; Howe, Katie E.; Hunter, Rebecca L.; and Hufford, Larry, "Biogeography of Mentzelia thompsonii and related species (Loasaceae)." (2024). Biology. 8.
https://digitalcommons.acu.edu/biology/8
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.