Name:
Canotia Phylogeography_MS_Revi ...
Size:
7.732Mb
Format:
PDF
Description:
Final Accepted Manuscript
Affiliation
Desert Laboratory on Tumamoc Hill, University of ArizonaDepartment of Ecology and Evolutionary Biology, University of Arizona
School of Natural Resources and the Environment, University of Arizona
Issue Date
2022-01
Metadata
Show full item recordPublisher
Elsevier BVCitation
Wilder, B. T., Becker, A. T., Munguia-Vega, A., & Culver, M. (2022). Tracking the desert’s edge with a Pleistocene relict. Journal of Arid Environments.Journal
Journal of Arid EnvironmentsRights
© 2021 Elsevier Ltd. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
In addition to the Sky Islands of the southwestern U.S. and northwestern Mexico, a series of 900–1200 m desert peaks surrounded by arid lowlands support temperate affiliated species at their summits. The presence of disjunct long-lived plant taxa on under-explored desert mountains, especially Isla Tiburón at 29° latitude in the Gulf of California, suggests a more southerly extent of Ice Age woodlands than previously understood. The phylogeography of the desert edge species Canotia holacantha (Celastraceae) was investigated to test the hypothesis that insular desert peak populations represent remnants of Pleistocene woodlands rather than recent dispersal events. Sequences of four chloroplast DNA regions totaling 2032 bp were amplified from 74 individuals of 14 populations across the entire range of C. holacantha as well as nine individuals that represented the other two species in its clade (C. wendtii and Acanthothamnus aphyllus) and two outgroups. Results suggest that a Canotia common ancestor occurred on the landscape, which underwent a population contraction ca. 15 kya. The Isla Tiburón C. holacantha population and the Chihuahuan Desert microendemic C. wendtii have the greatest genetic differentiation, are sister to one another, and basal to all other Canotia populations. Three haplotypes within C. holacantha were recovered, which correspond to regional geography and thus identified as the Arizona, Sonora, and Tiburón haplotypes, within which Acanthothamnus aphyllus is nested rather than as a sister genus. These results indicate a once broad distribution of Canotia/Acanthothamnus when the current peripheral desert ecotone habitat was more widespread during the Pleistocene, now present in relict populations on the fringes of the southern desert, in the Chihuahuan Desert, with scattered populations on desert peaks, and a common or abundant distribution at the northern boundary of the Sonoran Desert. These results suggest Canotia has tracked the shift of the desert's edge both in latitude and elevation since the end of the last Ice Age.Note
24 month embargo; available online 27 October 2021ISSN
0140-1963Version
Final accepted manuscriptae974a485f413a2113503eed53cd6c53
10.1016/j.jaridenv.2021.104653