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Steve Leavitt

Assistant Professor
Biology

4143 LSB
Provo, UT 84602

Biography

Teaching Interests


General biology, Symbioses, Evolution, Lichenology

Research Interests


Evolutionary diversification, molecular systematics and phylogenomics, role of species interactions within an evolutionary context, fungal symbioses, biogeography in arid environments, conservation, climate change and bio-monitoring, and scientific education and outreach.

Courses Taught


Winter 2019

  • BIO 130: Biology Section 001, 002, 003, 004, 005
  • BIO 494R: Mentored Research Section 025, 040
  • BIO 699R: Master's Thesis Section 016

Fall 2018

  • BIO 494R: Mentored Research Section 024
  • BIO 654: Speciation and Phylogeography Section 001
  • BIO 699R: Master's Thesis Section 017

Summer 2018

  • BIO 494R: Mentored Research Section 023

Spring 2018

  • BIO 511: Lichenology Section 001

Research Interests

Evolutionary diversification, molecular systematics and phylogenomics, role of species interactions within an evolutionary context, fungal symbioses, biogeography in arid environments, conservation, climate change and bio-monitoring, and scientific education and outreach.

Teaching Interests

General biology, Symbioses, Evolution, Lichenology

Professional Citizenship

  • Other, American Bryological and Lichenological Society, 2017-07-01 - 2017-07-31 - Present
  • Editor, Associate Editor, The Bryologist, 2014-01-01 - 2014-01-31 - Present
  • Reviewer, Ad Hoc Reviewer, Mycokeys, 2019-11-01 - 2019-11-30 - 2020-01-01 - 2020-01-31
  • Reviewer, Ad Hoc Reviewer, Journal of Biogeography, 2019-09-01 - 2019-09-30 - 2019-09-01 - 2019-09-30
  • Reviewer, Ad Hoc Reviewer, Northeastern Naturalist, 2019-09-01 - 2019-09-30 - 2019-09-01 - 2019-09-30
  • Reviewer, Ad Hoc Reviewer, Frontiers, 2019-07-01 - 2019-07-31 - 2019-07-01 - 2019-07-31
  • Reviewer, Ad Hoc Reviewer, Microorganisms , 2019-04-01 - 2019-04-30 - 2019-04-01 - 2019-04-30
  • Reviewer, Ad Hoc Reviewer, Plant and Fungal Systematics, 2019-04-01 - 2019-04-30 - 2019-04-01 - 2019-04-30
  • Reviewer, Ad Hoc Reviewer, PlosOne, 2019-03-01 - 2019-03-31 - 2019-03-01 - 2019-03-31
  • Reviewer, Ad Hoc Reviewer, Mycotaxon, 2018-12-01 - 2018-12-31 - 2018-12-01 - 2018-12-31
  • Guest Speaker, Eureka High School, Nevada, 2018-10-01 - 2018-10-31 - 2018-10-01 - 2018-10-31
  • Reviewer, Ad Hoc Reviewer, Symbiosis, 2018-10-01 - 2018-10-31 - 2018-10-01 - 2018-10-31
  • Reviewer, Ad Hoc Reviewer, The Bryologist, 2018-10-01 - 2018-10-31 - 2018-10-01 - 2018-10-31
  • Reviewer, Ad Hoc Reviewer, Mycokeys, 2018-09-01 - 2018-09-30 - 2018-09-01 - 2018-09-30
  • Reviewer, Ad Hoc Reviewer, The Lichenologist, 2018-09-01 - 2018-09-30 - 2018-09-01 - 2018-09-30
  • Reviewer, Ad Hoc Reviewer, USDA Forest Service General Technical Report Review Committee, 2017-06-01 - 2017-06-30 - 2018-09-01 - 2018-09-30
  • Reviewer, Ad Hoc Reviewer, The Lichenologist, 2018-07-01 - 2018-07-31 - 2018-07-01 - 2018-07-31
  • Grant Proposal Reviewer, External, Fungal Biology, 2018-06-01 - 2018-06-30 - 2018-06-01 - 2018-06-30
  • Reviewer, Ad Hoc Reviewer, Mycokeys, 2018-06-01 - 2018-06-30 - 2018-06-01 - 2018-06-30
  • Reviewer, Ad Hoc Reviewer, Proceedings of the Royal Society B, 2018-06-01 - 2018-06-30 - 2018-06-01 - 2018-06-30
  • Editor, Associate Editor, Phytotaxa, 2016-12-01 - 2016-12-31 - 2018-06-01 - 2018-06-30
  • Reviewer, Ad Hoc Reviewer, Mycokeys, 2018-05-01 - 2018-05-31 - 2018-05-01 - 2018-05-31
  • Reviewer, Ad Hoc Reviewer, Molecular Ecology, 2018-04-01 - 2018-04-30 - 2018-04-01 - 2018-04-30
  • Reviewer, Ad Hoc Reviewer, Scientific Reports, 2018-04-01 - 2018-04-30 - 2018-04-01 - 2018-04-30
  • Guest Speaker, Duschesne Elementary School, 2018-03-01 - 2018-03-31 - 2018-03-01 - 2018-03-31
  • Reviewer, Ad Hoc Reviewer, Journal of Biogeography, 2018-03-01 - 2018-03-31 - 2018-03-01 - 2018-03-31
  • Reviewer, Ad Hoc Reviewer, Molecular Phylogenetics and Evolution, 2018-03-01 - 2018-03-31 - 2018-03-01 - 2018-03-31
  • Reviewer, Ad Hoc Reviewer, Annals of Botany, 2018-02-01 - 2018-02-28 - 2018-02-01 - 2018-02-28
  • Reviewer, Ad Hoc Reviewer, Phycologia, 2018-02-01 - 2018-02-28 - 2018-02-01 - 2018-02-28
  • Reviewer, Ad Hoc Reviewer, Journal of Phycology, 2018-01-01 - 2018-01-31 - 2018-01-01 - 2018-01-31
  • Reviewer, Ad Hoc Reviewer, Molecular Phylogenetics and Evolution, 2017-11-01 - 2017-11-30 - 2017-11-01 - 2017-11-30
  • Grant Proposal Reviewer, External, National Science Foundation, 2017-10-01 - 2017-10-31 - 2017-10-01 - 2017-10-31
  • Reviewer, Ad Hoc Reviewer, National Science Foundation, 2017-10-01 - 2017-10-31 - 2017-10-01 - 2017-10-31
  • Reviewer, Ad Hoc Reviewer, Symbiosis, 2017-09-01 - 2017-09-30 - 2017-09-01 - 2017-09-30
  • Grant Proposal Reviewer, External, Poland National Science Center, 2016-09-01 - 2016-09-30 - 2017-09-01 - 2017-09-30
  • Reviewer, Ad Hoc Reviewer, Molecular Ecology Resources, 2017-08-01 - 2017-08-31 - 2017-08-01 - 2017-08-31
  • Officer (specify in Other), National Park Service - BioBlitz, 2017-01-01 - 2017-01-31 - 2017-07-01 - 2017-07-31
  • Reviewer, Ad Hoc Reviewer, Molecular Phylogenetics and Evolution, 2017-06-01 - 2017-06-30 - 2017-06-01 - 2017-06-30
  • Reviewer, Ad Hoc Reviewer, USDA United States Forest Service, 2017-04-01 - 2017-04-30 - 2017-06-01 - 2017-06-30
  • Reviewer, Ad Hoc Reviewer, American Journal of Botany, 2017-05-01 - 2017-05-31 - 2017-05-01 - 2017-05-31
  • Reviewer, Ad Hoc Reviewer, Botany, 2017-03-01 - 2017-03-31 - 2017-03-01 - 2017-03-31
  • Committee/Council Member, International Botanical Congress Grant Assessment Committee, 2017-03-01 - 2017-03-31 - 2017-03-01 - 2017-03-31
  • Reviewer, Ad Hoc Reviewer, The Bryologist, 2017-03-01 - 2017-03-31 - 2017-03-01 - 2017-03-31
  • Committee/Council Member, International Botanical Congress, 2017-02-01 - 2017-02-28 - 2017-03-01 - 2017-03-31
  • Reviewer, Ad Hoc Reviewer, Fungal Diversity, 2017-02-01 - 2017-02-28 - 2017-02-01 - 2017-02-28
  • Reviewer, Ad Hoc Reviewer, Molecular Ecology, 2017-02-01 - 2017-02-28 - 2017-02-01 - 2017-02-28
  • Reviewer, Ad Hoc Reviewer, Nova Hedwigia, 2017-02-01 - 2017-02-28 - 2017-02-01 - 2017-02-28
  • Reviewer, Ad Hoc Reviewer, Frontiers, 2017-01-01 - 2017-01-31 - 2017-01-01 - 2017-01-31
  • Reviewer, Ad Hoc Reviewer, Frontiers, 2016-10-01 - 2016-10-31 - 2016-10-01 - 2016-10-31
  • Reviewer, Ad Hoc Reviewer, Molecular Ecology Resources, 2016-10-01 - 2016-10-31 - 2016-10-01 - 2016-10-31
  • Conference-Related Role, Trebouxia working group, 2016-01-01 - 2016-01-31 - 2016-09-01 - 2016-09-30
  • Grant Proposal Reviewer, External, Czech Science Foundation, 2012-11-01 - 2012-11-30 - 2016-09-01 - 2016-09-30
  • Grant Proposal Reviewer, External, National Geographic Society, 2015-08-01 - 2015-08-31 - 2016-08-01 - 2016-08-31
  • Committee/Council Member, American Bryological and Lichenological Society, 2015-11-01 - 2015-11-30 - 2016-02-01 - 2016-02-28
  • Reviewer, Ad Hoc Reviewer, Genome Biology and Evolution, 2015-10-01 - 2015-10-31 - 2015-10-01 - 2015-10-31
  • Grant Proposal Reviewer, External, National Fellowships Committee for Sigma Delta Epsilon, Graduate Women in Science, 2015-09-01 - 2015-09-30 - 2015-09-01 - 2015-09-30
  • Conference-Related Role, Botanical Society of America, 2015-01-01 - 2015-01-31 - 2015-07-01 - 2015-07-31
  • Conference-Related Role, Botanical Society of America, 2014-01-01 - 2014-01-31 - 2014-07-01 - 2014-07-31

Courses Taught

2020

  • BIO 494R: Section 014
  • BIO 100 : Section 019
  • BIO 100 : Section 020
  • BIO 100 : Section 021
  • BIO 100 : Section 040
  • BIO 654 : Section 001
  • BIO 494R: Section 012
  • BIO 130 : Section 001
  • BIO 130 : Section 003
  • BIO 130 : Section 008
  • BIO 130 : Section 009
  • BIO 130 : Section 010
  • BIO 494R: Section 023

2019

  • BIO 799R: Section 017
  • BIO 494R: Section 022
  • BIO 100 : Section 031
  • BIO 100 : Section 032
  • BIO 100 : Section 033
  • BIO 100 : Section 034
  • BIO 100 : Section 035
  • BIO 494R: Section 023
  • BIO 494R: Section 010
  • BIO 130 : Section 001
  • BIO 130 : Section 002
  • BIO 130 : Section 003
  • BIO 130 : Section 004
  • BIO 130 : Section 005
  • BIO 699R: Section 016
  • BIO 494R: Section 025
  • BIO 494R: Section 040

2018

  • BIO 699R: Section 017
  • BIO 494R: Section 024
  • BIO 654 : Section 001
  • BIO 494R: Section 023
  • BIO 511 : Section 001
  • BIO 559R: Section 017
  • BIO 100 : Section 007

2017

  • BIO 494R: Section 26
  • BIO 100 : Section 001
  • BIO 100 : Section 001
  • BIO 559R: Section 002
  • BIO 100 : Section 011

2013

  • BIO 100 : Section 004

Publications

  • Leavitt SD, Smith B. 2020. Baseline population density estimates of rock shield lichens relative to mountain goats in the La Sal Mountains, Utah, USA.
  • Esslinger TL, McCune B, Leavitt SD. 2020. Two closely related but morphologically disparate new species of Physcia from Western North America.
  • Grewe F, Ametrano C, Wilhelm TJ, Leavitt SD, Distefano I, Polyiam W, Pizarro D, Wedin M, Crespo A, Divakar PK, et alDecember 14, 2020. Using target enrichment sequencing to study the higher-level phylogeny of the largest lichen-forming fungi family: Parmeliaceae (Ascomycota).
  • Smith H, Grande FD, Muggia L, Keuler R, Divakar PK, Grewe F, Schmitt I, Lumbsch T, Leavitt SD. October (4th Quarter/Autumn) 22, 2020. Data mining metagenomic sequencing reads reveals diverse, lichen-specific mycobiomes.
  • Muggia L, Nelsen MP, Kirika PM, Barreno E, Beck A, Lindgren H, Lumbsch T, Leavitt SD. August, 2020. Formally described species woefully underrepresent phylogenetic diversity in the predominant lichen photobiont genus Trebouxia (Trebouxiophyceae, Chlorophyta): impetus for developing an integrated taxonomy.
  • LaGreca S, Lumbsch T, Kukwa M, Wei X, Han JE, Moon KH, Kashiwadani H, Aptroot A, Leavitt SD. June 3, 2020. A molecular phylogenetic evaluation of the Ramalina siliquosa complex, with notes on species circumscription and relationships within Ramalina.
  • Keuler R, Garretson A, Saunders T, Erickson RJ, Andre NS, Grewe F, Smith H, Lumbsch T, Huang J, Clair LLS, et alJanuary (1st Quarter/Winter) 30, 2020. Genome-scale data reveal the potential role of hybrid speciation in lichen-forming fungi.
  • Bradshaw M, Grewe F, Thomas A, Harrison C, Lindgren H, Muggia L, Clair LLS, Lumbsch T, Leavitt SD. January (1st Quarter/Winter) 6, 2020. Characterizing the ribosomal tandem repeat and its utility as a DNA barcode in lichen-forming fungi.
  • Leavitt SD, Keuler R, Newberry C, Rosentreter R, Clair LLS. December, 2019. A blast from the past: Shotgun sequencing decades-old lichen specimens to resolve phylogenomic placement of type specimens. 2nd ed.
  • StClair LL, Leavitt SD. 2019. Anderson and Shushan: Lichens of Western North America Fascicle VII. 2nd ed.
  • Warren SD, StClair LL, Leavitt SD. 2019. Aerobiology and passive restoration of biological soil crusts.
  • Carter O, Kropp B, Noell N, Hollinger J, Baker G, Tuttle A, Clair LLS, Leavitt SD. December 12, 2019. A Preliminary Checklist of the Lichens in Great Basin National Park, Nevada, USA. 3rd ed.
  • Ametrano CG, Grewe F, Crous PE, Goodwin SB, Liang C, Selbmann L, Lumbsch HT, Leavitt SD, Muggia L. October (4th Quarter/Autumn) 30, 2019. Genome-scale data resolve ancestral rock-inhabiting lifestyle in Dothideomycetes (Ascomycota). 1st ed.
  • Hale E, Fisher ML, Keuler R, Smith B, Leavitt SD. July (3rd Quarter/Summer) 12, 2019. A biogeographic connection between Antarctica and montane regions of western North America highlights the need for further study of lecideoid lichens. 2nd ed.
  • Huang J, Kraichak E, Leavitt SD, Nelsen MP, Lumbsch HT. June, 2019. Accelerated diversifications in three diverse families of morphologically complex lichen-forming fungi link to major historical events.
  • Leavitt SD, Kropp B. June 3, 2019. Lichen Diversity in Great Basin National Park. 1st ed.
  • Divakar PK, Wei X, McCune B, Cubas P, Boluda CG, Leavitt SD, Crespo A, Tchabanenko S, Lumbsch HT. May, 2019. Parallel Miocene dispersal events explain the cosmopolitan distribution of the Hypogymnioid lichens. 5th ed.
  • Lumbsch T, Leavitt SD. April (2nd Quarter/Spring), 2019. Introduction of subfamily names for four clades in Cladoniaceae and Peltigeraceae (Lecanoromycetes).
  • Wright B, StClair LL, Leavitt SD. March, 2019. Is targeted community DNA metabarcoding suitable for biodiversity inventories of lichen-forming fungi?.
  • Pizarro D, Grande FD, Leavitt SD, Dyer PS, Schmitt I, Crespo A, Lumbsch HT, Divakar PK. February 4, 2019. Whole-Genome Sequence Data Uncover Widespread Heterothallism in the Largest Group of Lichen-Forming Fungi. 3rd ed.
  • Kraichak E, Huang J, Nelsen M, Leavitt SD, Lumbsch HT. September, 2018. A revised classification of orders and families in the two major subclasses of Lecanoromycetes (Ascomycota) based on a temporal approach. 3rd ed.
  • Barcenas-Peña A, Leavitt SD, Huang J, Grewe F, Lumbsch HT. September 18, 2018. Phylogenetic study and taxonomic revision of the Xanthoparmelia mexicana group, including the description of a new species (Parmeliaceae, Ascomycota).
  • Leavitt SD, Westberg M, Nelsen MP, Elix JA, Timdal E, Sohrabi M, StClair LL, Williams L, Wedin M, Lumbsch H. February, 2018. Multiple, Distinct Intercontinental Lineages but Isolation of Australian Populations in a Cosmopolitan Lichen-Forming Fungal Taxon, Psora decipiens (Psoraceae, Ascomycota).
  • Wei X, Leavitt SD, Huang J, Esslinger TL, Wang L, Moncada B, Lücking R, Divakar PK, Lumbsch HT. December, 2017. Parallel Miocene-dominated diversification of the lichen-forming fungal genus Oropogon (Ascomycota: Parmeliaceae) in different continents. 6th ed.
  • Mark K, Saag L, Leavitt SD, Will-Wolf S, Nelsen MP, Tõrra T, Saag A, Randlane T, Lumbsch HT. 2017. Erratum to: Evaluation of traditionally circumscribed species in the lichen-forming genus Usnea, section Usnea (Parmeliaceae, Ascomycota) using a six-locus dataset. 1st ed.
  • Grewe F, Huang J, Leavitt SD, Lumbsch HT. August, 2017. Reference-based RADseq resolves robust relationships among closely related species of lichen-forming fungi using metagenomic DNA.
  • Nuñez-Zapata J, Alors D, Cubas P, Divakar PK, Leavitt SD, Lumbsch HT, Crespo A. July (3rd Quarter/Summer), 2017. Understanding disjunct distribution patterns in lichen-forming fungi: insights from Parmelina (Parmeliaceae: Ascomycota).
  • Kirika PM, Divakar PK, Buaruang K, Leavitt SD, Crespo A, Gatheri GW, Mugambi G, Benatti MN, Lumbsch HT. June, 2017. Molecular phylogenetic studies unmask overlooked diversity in the tropical lichenized fungal genus Bulbothrix sl (Parmeliaceae, Ascomycota). 3rd ed.
  • Kirika PM, Divakar PK, Leavitt SD, KB, Crespo A, Mugambi G, Gatheri GW, Lumbsch HT. May, 2017. The genus Relicinopsis is nested within Relicina (Parmeliaceae, Ascomycota). 3rd ed.
  • Sodamuk M, Boonpragob K, Mongkolsuk P, Tehler A, Leavitt SD, Lumbsch HT. May 02, 2017. Kalbionora palaeotropica, a new genus and species from coastal forests in Southeast Asia and Australia (Malmideaceae, Ascomycota).
  • Kraichak E, Crespo A, Divakar PK, Leavitt SD, Lumbsch HT. May 23, 2017. A temporal banding approach for consistent taxonomic ranking above the species level.
  • Lücking R, Hodkinson BP, Leavitt SD. April (2nd Quarter/Spring) 17, 2017. Corrections and amendments to the 2016 classification of lichenized fungi in the Ascomycota and Basidiomycota. 1st ed.
  • Divakar PK, Crespo A, Kraichak E, Leavitt SD, Schmitt I, Lumbsch HT, Singh G. April (2nd Quarter/Spring) 11, 2017. Using a temporal phylogenetic method to harmonize family- and genus-level classification in the largest clade of lichen-forming fungi.
  • Zhao X, Fernández-Brime S, Wedin M, Locke M, Leavitt SD, Lumbsch HT. January (1st Quarter/Winter) 03, 2017. Using multi-locus sequence data for addressing species boundaries in commonly accepted lichen-forming fungal species. 2nd ed.
  • Leavitt SD, Divakar PK, Crespo A, Lumbsch HT. December, 2016. A matter of time – understanding the limits of the power of molecular data for delimiting species boundaries. 2nd ed.
  • Divakar PK, Leavitt SD, Molina MC, Del-Prado R, Lumbsch HT, Crespo A. 2016. A DNA barcoding approach for identification of hidden diversity in Parmeliaceae (Ascomycota): Parmelia sensu stricto as a case study. 1st ed.
  • Alors D, Lumbsch HT, Divakar PK, Leavitt SD, Crespo A. 2016. An integrative approach for understanding diversity in the Punctelia rudecta species complex (Parmeliaceae, Ascomycota). 2nd ed.
  • Lindgren H, Leavitt SD, Lumbsch HT. 2016. Characterization of microsatellite markers in the cosmopolitan lichen-forming fungus Rhizoplaca melanophthalma (Lecanoraceae).
  • Leavitt SD, Kraichak E, Vondrak J, Nelsen MP, Sohrabi M, Perez-Ortega S, StClair LL, Lumbsch HT. 2016. Cryptic diversity and symbiont interactions in rock-posy lichens.
  • Leavitt SD, Lumbsch HT. 2016. Ecological Biogeography of Lichen-Forming Fungi.
  • Mark K, Saag L, Leavitt SD, Will-Wolf S, Nelsen MP, Tõrra T, Saag A, Randlane T, Lumbsch HT. 2016. Evaluation of traditionally circumscribed species in the lichen-forming genus Usnea, section Usnea (Parmeliaceae, Ascomycota) using a six-locus dataset. 3rd ed.
  • Leavitt SD, Esslinger TL, Divakar PK, Crespo A, Lumbsch HT. 2016. Hidden diversity before our eyes: Delimiting and describing cryptic lichen-forming fungal species in camouflage lichens (Parmeliaceae, Ascomycota). 11th ed.
  • Kirika PM, Divakar PK, Crespo A, Gatheri GW, Mugambi G, Leavitt SD, Moncada B, Lumbsch HT. 2016. Molecular data show that Hypotrachyna sorocheila (Parmeliaceae) is not monophyletic. 2nd ed.
  • Kirika PM, Divakar PK, Crespo A, Mugambi G, Orock EA, Leavitt SD, Gatheri GW, Lumbsch HT. 2016. Phylogenetic studies uncover a predominantly African lineage in a widely distributed lichen-forming fungal species.
  • Widhelm TJ, Egan RS, Bertoletti FR, Asztalos MJ, Kraichak E, Leavitt SD, Lumbsch HT. 2016. Picking holes in traditional species delimitations: an integrative taxonomic reassessment of the Parmotrema perforatum group (Parmeliaceae, Ascomycota).
  • Leavitt SD, Grewe F, Widhelm TJ, Muggia L, Wray B, Lumbsch HT. 2016. Resolving evolutionary relationships in lichen-forming fungi using diverse phylogenomic datasets and analytical approaches.
  • Lücking R, Hodkinson BP, Leavitt SD. 2016. The 2016 classification of lichenized fungi in the Ascomycota and Basidiomycota – Approaching one thousand genera. 4th ed.
  • Altermann S, Leavitt SD, Goward T. 2016. Tidying up the genus Letharia: introducing L lupina sp nov and a new circumscription for L columbiana. 5th ed.
  • Zhao X, Leavitt SD, Zhao ZT, Zhang LL, Arup U, Grube M, Pérez-Ortega S, Printzen C, Sliwa L, Kraichak E, et al2016. Towards a revised generic classification of lecanoroid lichens (Lecanoraceae, Ascomycota) based on molecular, morphological and chemical evidence. 1st ed.
  • Kirika PM, Divakar PK, Crespo A, Leavitt SD, Mugambi G, Gatheri GW, Lumbsch HT. December 20, 2016. Polyphyly of the genus Canoparmelia—uncovering incongruences between phenotype-based classification and molecular phylogeny within lichenized Ascomycota (Parmeliaceae). 1st ed.
  • Wei X, McCune B, Lumbsch HT, Li H, Leavitt SD, Yamamoto Y, Tchabanenko S, Wei J. November, 2016. Limitations of species delimitation based on phylogenetic analyses: a case study in the Hypogymnia hypotrypa group (Parmeliaceae, Ascomycota). 11th ed.
  • Hawksworth DL, Lumbsch HT, Scholz P, Leavitt SD, Seaward MRD. 2015. (2396) Proposal to conserve the name Lichen muralis (Lecanora muralis, Protoparmeliopsis muralis) with a conserved type (Ascomycota: Lecanorales: Lecanoraceae). 6th ed.
  • Zhao X, Zhang LL, Zhao ZT, Wang WC, Leavitt SD, Lumbsch HT. 2015. A molecular phylogeny of the lichen genus Lecidella focusing on species from mainland China. 9th ed.
  • Kraichak E, Divakar PK, Crespo A, Leavitt SD, Nelsen MP, Lücking R, Lumbsch HT. 2015. A tale of two hyper-diversities: diversification dynamics of the two largest families of lichenized fungi.
  • Kantvilas G, Leavitt SD, Elix JA, Lumbsch HT. 2015. Additions to the genus Trapelia (Trapeliaceae: lichenised Ascomycetes). 6th ed.
  • Leavitt SD, StClair LL. 2015. Bio-monitoring in Western North America: What Can Lichens Tell Us About Ecological Disturbances?.
  • Singh G, Grande FD, Divakar PK, Otte J, Leavitt SD, Szczepanska K, Crespo A, Rico VJ, Aptroot A, Cáceres MEdS, et al2015. Coalescent-based species delimitation approach uncovers high cryptic diversity in the cosmopolitan lichen-forming fungal genus Protoparmelia (Lecanorales, Ascomycota). 5th ed.
  • Divakar PK, Crespo A, Wedin M, Leavitt SD, Hawksworth DL, Myllys L, McCune B, Randlane T, Bjerke JW, Ohmura Y, et al2015. Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi. 4th ed.
  • Leavitt SD, Kraichak E, Nelsen MP, Altermann S, Divakar PK, Alors D, Esslinger TL, Crespo A, Lumbsch HT. 2015. Fungal specificity and selectivity for algae play a major role in determining lichen partnerships across diverse ecogeographic regions in the lichen-forming family Parmeliaceae (Ascomycota). 14th ed.
  • Buaruang K, Scharnagl K, Divakar PK, Leavitt SD, Crespo A, Manoch L, Lücking R, Lumbsch HT, others. 2015. Molecular data support Pseudoparmelia as a distinct lineage related to Relicina and Relicinopsis (Ascomycota, Lecanorales). 01st ed.
  • Wang Q-, Yurkov AM, Gökerm M, Lumbsch HT, Leavitt SD, Groenewald M, Theelen B, Liu X-, Boekhout T, Bai F-. 2015. Phylogenetic classification of yeasts and related taxa within Pucciniomycotina.
  • Leavitt SD, Moreau CS, Lumbsch HT. 2015. The dynamic discipline of species delimitation: progress toward effectively recognizing species boundaries in natural populations.
  • Kirika PM, Leavitt SD, Divakar PK, Crespo A, Gatheri GW, Mugambi G, Lumbsch HT. 2015. The monotypic genus Bulborrhizina belongs to Bulbothrix sensu lato (Parmeliaceae, Ascomycota). 2nd ed.
  • Leavitt SD, Divakar PK, Ohmura Y, Wang L, Esslinger TL, Lumbsch HT. 2015. Who’s getting around? Assessing species diversity and phylogeography in the widely distributed lichen-forming fungal genus Montanelia (Parmeliaceae, Ascomycota).
  • Leavitt SD, Esslinger TL, Hansen ES, Divakar PK, Crespo A, Loomis BF, Lumbsch HT. 2014. DNA barcoding of brown Parmeliae (Parmeliaceae) species: a molecular approach for accurate specimen identification, emphasizing species in Greenland. 1st ed.
  • Schoch CL, Robbertse B, Robert V, Vu D, Cardinali G, Irinyi L, Meyer W, Nilsson RH, Hughes K, Miller AN, et al2014. Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi.
  • Altermann S, Leavitt SD, Goward T, Nelsen MP, Lumbsch HT. 2014. How do you solve a problem like Letharia? A new look at cryptic species in lichen-forming fungi using Bayesian clustering and SNPs from multilocus sequence data. 5th ed.
  • Shrestha G, Raphael J, Leavitt SD, StClair LL. 2014. In vitro evaluation of the antibacterial activity of extracts from 34 species of North American lichens. 10th ed.
  • Esslinger TL, Hansen ES, Leavitt SD. 2014. The brown parmelioid lichen species in Greenland.
  • Nelsen MP, Thell A, Leavitt SD, Hampton-Miller CJ, Lumbsch HT. 2013. A reappraisal of Masonhalea (Parmeliaceae, Lecanorales) based on molecular and morphological data. 06th ed.
  • Leavitt SD, Lumbsch HT, StClair LL. 2013. Contrasting demographic histories of two species in the lichen-forming fungal genus Xanthomendoza (Teloschistaceae, Ascomycota). 4th ed.
  • Leavitt SD, Fernández-Mendoza F, Pérez-Ortega S, Divakar PK, Lumbsch HT, StClair LL. 2013. DNA barcode identification of lichen-forming fungal species in the Rhizoplaca melanophthalma species-complex (Lecanorales, Lecanoraceae), including five new species.
  • StClair LL, Leavitt SD. 2013. Final Report Concerning Establishment of a Lichen Air Quality Bio-monitoring Program for the Quinn Canyon and Grant Range Wilderness Areas, Humboldt Toiyabe National Forest, Nevada.
  • StClair LL, Leavitt SD. 2013. Final Report Concerning Establishment of a Lichen Air Quality Bio-monitoring Program for the South Unit of the Duchesne Ranger District, Ashley National Forest and Detailed Elemental Analysis Survey of the Cart Creek Bridge and Selected Sites along US Highway 191, Utah .
  • StClair LL, Clair SBS, Leavitt SD. 2013. Final Report concerning Review of the lichen air quality baseline for Region 1 of the Forest Service, Montana and Idaho.
  • Leavitt SD, Esslinger TL, Nelsen MP, Lumbsch HT. 2013. Further species diversity in Neotropical Oropogon (Lecanoromycetes: Parmeliaceae) in Central America. 04th ed.
  • Parnmen S, Leavitt SD, Rangsiruji A, Lumbsch HT. 2013. Identification of species in the Cladia aggregata group using DNA barcoding (Ascomycota: Lecanorales). 1st ed.
  • Leavitt SD, Fernández-Mendoza F, Pérez-Ortega S, Sohrabi M, Divakar PK, Vondrák J, Lumbsch HT, StClair LL. 2013. Local representation of global diversity in a cosmopolitan lichen-forming fungal species complex (Rhizoplaca, Ascomycota). 9th ed.
  • Leavitt SD, Esslinger TL, Spribille T, Divakar PK, Lumbsch HT. 2013. Multilocus phylogeny of the lichen-forming fungal genus Melanohalea (Parmeliaceae, Ascomycota): Insights on diversity, distributions, and a comparison of species tree and concatenated topologies. 1st ed.
  • Leavitt SD, Lumbsch HT, Stenroos S, StClair LL. 2013. Pleistocene speciation in North American lichenized fungi and the impact of alternative species circumscriptions and rates of molecular evolution on divergence estimates. 12th ed.
  • Leavitt SD, Nelsen MP, Lumbsch HT, Johnson LA, StClair LL. 2013. Symbiont flexibility in subalpine rock shield lichen communities in the Southwestern USA. 2nd ed.
  • Sohrabi M, Leavitt SD, Rico VJ, Halici MG, Shrestha G, Stenroos S. 2013. Teuvoa, a new lichen genus in Megasporaceae (Ascomycota: Pertusariales), including Teuvoa junipericola sp nov. 03rd ed.
  • Leavitt SD, Nelsen MP, StClair LL. 2013. Treading in murky waters: Making sense of diversity in Xanthoparmelia (Parmeliaceae, Ascomycota) in theWestern United States. 2nd ed.
  • Divakar PK, Kauff F, Crespo A, Leavitt SD, Lumbsch HT. 2013. Understanding phenotypical character evolution in parmelioid lichenized fungi (Parmeliaceae, Ascomycota). 11th ed.
  • Shrestha G, Leavitt SD, Proulx MW, Glacy LA, Call C, Hendrickson J, StClair LL. 2012. A Checklist of the lichens of the Beaver Dam Slope, Washington County, Utah, USA.
  • Esslinger TL, Morse CA, Leavitt SD. 2012. A new North American species of Hyperphyscia (Physciaceae). 1st ed.
  • Thell A, Crespo A, Divakar PK, Kärnefelt I, Leavitt SD, Lumbsch HT, Seaward MR. 2012. A review of the lichen family Parmeliaceae–history, phylogeny and current taxonomy. 6th ed.
  • Divakar PK, Del-Prado R, Lumbsch HT, Wedin M, Esslinger TL, Leavitt SD, Crespo A. 2012. Diversification of the newly recognized lichen-forming fungal lineage Montanelia (Parmeliaceae, Ascomycota) and its relation to key geological and climatic events. 12th ed.
  • Orock EA, Leavitt SD, Fonge BA, StClair LL, Lumbsch HT. 2012. DNA-based identification of lichen-forming fungi: can publicly available sequence databases aid in lichen diversity inventories of Mount Cameroon (West Africa)?. 06th ed.
  • Leavitt SD, Esslinger TL, Divakar PK, Lumbsch HT. 2012. Miocene and Pliocene dominated diversification of the lichen-forming fungal genus Melanohalea (Parmeliaceae, Ascomycota) and Pleistocene population expansions. 1st ed.
  • Leavitt SD, Esslinger TL, Lumbsch HT. 2012. Neogene-dominated diversification in neotropical montane lichens: dating divergence events in the lichen-forming fungal genus Oropogon (Parmeliaceae). 11th ed.
  • Schoch CL, Seifert KA, Huhndorf S, Robert V, Spouge JL, Levesque CA, Chen W, Bolchacova E, Voigt K, Crous PW, et al2012. Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for Fungi. 16th ed.
  • Leavitt SD, Johnson L, StClair LL. 2011. Species delimitation and evolution in morphologically and chemically diverse communities of the lichen-forming genus Xanthoparmelia (Parmeliaceae, Ascomycota) in western North America. 2nd ed.
  • Leavitt SD, StClair LL. 2008. Lichens of the Boulder Mountain Plateau, Wayne County, Utah, USA. 4th ed.
  • Jackson HB, Leavitt SD, Krebs T, StClair LL. 2005. Lichen flora of the eastern Mojave Desert: Blackrock Arizona, Mojave County, Arizona, USA. 1st ed.

Presentations

  • Keuler RA, Jensen J, Leavitt SD. Hybridization in the diversification processes in the most speciose genus of lichen-forming fungi, Xanthoparmelia . Botany 2020 . Hybridization has been detected increasingly in genomes across kingdoms, likely playing an important role in evolution While its impacts on evolutionary processes has been well-documented with pathogenic fungi, the study of hybridization among lichen-forming fungi is in its infancy, and the question remains of how involved it might be in the diversification of symbiotic fungi Xanthoparmelia is the most diverse genus of lichen-forming fungi, with a pattern of diversification that coincides with global aridification The monophyletic Holarctic clade in Xanthoparmeliais comprised of Asian, European, and North American species that diverged roughly 7 million years ago Because hybridization can facilitate rapid adaptive radiations, providing standing variation for later speciation events to act on, we investigated whether hybridization played a role in the diversification within the Holarctic clade We used nuclear phylogenomic data to reconstruct species trees and infer reticulate relationships While putative species-level lineages were well-supported, there was rampant discordance among the 962 sampled gene trees A reticulate evolutionary history among these taxa was detected using three independent tests of hybridization (PhyloNet, ABBA-BABA, and QuIBL), suggesting deeper-level reticulation among ancestral members of the Holarctic clade More research needs to be done to investigate potential patterns of hybridization and its possible relationship to the diverse morphology within Xanthoparmelia Our results support the need to consider the role of hybridization might be in the diversification of lichen-forming fungi. July, 2020.
  • Burgoyne J, Jensen J, Summerhays S, Leavitt SD. Exploring Cave Biofilm Diversity in Great Basin National Park. Utah Conference on Undergraduate Research . February, 2020.
  • Leavitt SD. Lichens as tools to monitor disturbances in the La Sal Mountains. Canyonlands Natural History Association. January, 2020.
  • Leavitt SD, Smith H. How many fungi make a lichen? A perspective of increasing complexity in symbiosis". Illumina Sequencing Seminar. December, 2019.
  • Fisher ML, Nelson CRR, Leavitt SDD, Zaspel JM. Host preference and selective sequestration in the lichen-feeding tiger moths (Erebidae: Arctiinae: Lithosiini) . Annual Meeting of the Entomological Society of America. Second prize for the Student Competition for the President's
    Award!. November, 2019.
  • Keuler R, Garrestson A, Saunders T, Erickson R, Andre NS, Grewe F, Smith H, Lumbsch T, Clair LS, Leavitt SD. Genome-scale data reveal the potential roleof hybrid speciation in lichen-forming fungi. Botany 2019. Advancements in molecular genetics have revealed that hybridization is common among plants, animals, and fungi, playing an important role in evolutionary dynamics and speciation One genetic indicator of hybridization is the discordance between mitochondrial and nuclear phylogenetic trees While hybridization has been well-documented in plant pathogenic fungi, the effects of this process on species boundaries in lichenized fungi are largely unexplored Here we investigated the potential role of hybridization on the emergence of morphologically and reproductively distinct asexual vagrant lichen forms within a clade of rock-dwelling, sexually reproducing species, the Rhizoplaca melanophthalma group We used phylogenomic data from both mitochondrial and nuclear genomes representing all known species within the R melanophthalma complex to infer evolutionary relationships and potential hybridization/introgression We inferred strongly supported phylogenies from both the nuclear and mitochondrial datasets, both recovering multiple independent origins of vagrant Rhizoplaca populations We observed multiple instances of discordance between the mitochondrial and nuclear trees, including the clade comprising the asexual vagrant species R haydenii, R idahoensis, and a closely related rock-dwelling lineage In spite of well-supported phylogenies, both from a concatenated super matrix approach and multiple coalescent-based species tree approaches, we recovered strong evidence of reticulation using a network approach that incorporates both incomplete lineage sorting and hybridization These data suggest that the western North American subalpine endemic R shushanii is likely the result of a hybrid speciation event, and hybridization may have also played a role in other taxa, including vagrant lineages Here we provide novel perspective into the role of hybridization/introgression in the process of speciation in lichen-forming fungi based on genome-scale data We discuss potential roles of hybridization/introgression in terms of generating novel traits in lichens Furthermore, our results support the need for considering reticulate phylogenies when investigating species boundaries and evolutionary history, even in cases with well-supported topologies inferred from genome-scale data. July, 2019.
  • Smith H, Leavitt SD. Metagenomic sequencing reveals diverse, lichen-specific mycobiomes. Botany 2019. Lichens have traditionally been considered to be the symbiotic phenotype from the interactions of a single fungal partner and a single photosynthetic partner However, the lichen symbiosis has been shown to be far more complex and may include a wide range of other interacting organisms, including bacteria, accessory fungi, and algae Recently, a ‘third partner’, basidiomycete yeasts, have been proposed to play an essential role in some macrolichens In this study, we used metagenomic shotgun sequencing to better characterize lichen mycobiomes Specifically, we inferred the range of fungi associated within lichen thalli from five groups of lichens – Bryoria, Physciaceae,Rhizoplaca, Umbilicaria, and Xanthoparmelia Metagenomic reads representing the multi-copy nuclear ribosomal internal transcribed spacer region (ITS), the standard DNA barcode region for fungi, were extracted, clustered, and used to infer taxonomic assignments Our data revealed complex and often lichen-specific mycobiomes, with each lichen metagenome comprising a significant proportion of reads from accessory fungal lineages Many of the members of the lichen-associated lichen mycobiomes identified here have not previously been found in association with lichens We found little evidence supporting the ubiquitous presence of Cystobasidiales yeasts in macrolichens, although reads representing this putative ‘third’ lichen symbiont were found in Bryoria samples in low abundance Our study further highlights the ecosystem-like features of lichens, with partners and interactions far from being completely understood Future research is needed to more fully and accurately characterize lichen mycobiomes and how these fungi interact with the traditionally considered major lichen components – the photo- and mycobionts. July, 2019.
  • Fisher ML, Zaspel J, Nelson CR, Leavitt SD. Are you what you eat? Patterns of chemical sequestration in the lichen-feeding tiger moth Cisthene angelus (Lepidoptera: Erebidae: Arctiinae: Lithosiini). Entomological Society of America, Entomological Society of Canada, and Entomological Society of British Columbia Joint Annual Meeting. November, 2018.
  • Fisher ML, Nelson CR, Leavitt SD. Pick your poison, the decision of what’s for dinner for the lichenivorous caterpillars of Cisthene angelus (Dyar) (Lepidoptera: Erebidae: Arctiinae) . Ohio Valley Entomological Association. October, 2018.
  • Hale E, Fisher M, Leavitt SD. A Biogeographic Connection between Antarctica and the Great Basin. American Bryological and Lichenological Society 2018. August, 2018.
  • Fisher M, Nelson CR, Leavitt SD. Pick your poison, the decision of what’s for dinner for lichenivorous caterpillars. American Bryological and Lichenological Society 2018. August, 2018.
  • Wright B, Leavitt SD. Using field-based inventories and high-throughput sequencing to assess dispersal versus establishment of lichen-forming fungi. American Bryological and Lichenological Society 2018,. August, 2018.
  • Leavitt SD, Wright B. How many fungi and algae does it take to make a lichen? Looking beyond simple two-partner system? . 2018 International Symbiosis Society Congress. July, 2018.
  • Ametrano CG, Grewe F, Knudsen K, Lumbsch T, Leavitt SD, Muggia L. First insight into the genome of Lichenothelia and Saxomyces: a class-wide phylogenomic perspective. IMC11. July, 2018.
  • Fisher MF, Nelson CR, Leavitt SD. You are What You Eat: The Strange Feeding Behavior of Lichen Eating Caterpillars. BYU Graduate Student Society Grad Expo. April, 2018.
  • Leavitt SD. Around the world in how many days? Insight into biogeography of cosmopolitan lichens. A Watson Armour Seminar Series. November, 2017.
  • Grewe F, Huang J, Leavitt SD, Lumbsch HT. Mitochondrial genomes in symbiotic organisms: lineage specific variation across lichen-forming fungi. Mitochondrial Genomics and Evolution – an SMBE Satellite Meeting . September, 2017.
  • Leavitt SD. Parallel Miocene-dominated diversification of the lichen-forming fungal genus Oropogon (Parmeliaceae, Ascomycota) in different continents. IX Congreso Colombiano de Botanica (Tunja, Colombia) . August, 2017.
  • Leavitt SD, Westberg M, Sohrabi M, Elix J, StClair LL, Lumbsch HT. Biogeography in a common, cosmopolitan lichen-forming fungal component of biological soil crusts, Psora decipiens (Psoraceae, Ascomycota). Botany 2017. Multiple drivers shape the spatial distribution of species, including plate tectonics, climatic transitions, orographic barriers, species’ dispersal capacity, etc However, biogeographic patterns of lichens commonly do not fit conventional expectations based on studies of animals and plants For example, a number of lichens are known to occur across impressively broad, intercontinental distributions, including some important components of biological soil crust communities (BSCs) The lichen-forming fungal species Psora decipiens (Hedw) Hoffm is found on all continents, except South America and Antarctica This lichen occurs in BSCs in diverse habitats, ranging from hot, arid deserts to alpine steppe/tundra communities In order to better understand factors that shape population structure in widespread lichen-forming fungal species, we investigated biogeographic patterns in the cosmopolitan taxon Psora decipiens, along with the closely related taxa Psora crenata (Taylor) Reinke, Jb wiss and P saviczii (Tomin) Follmann & A Crespo We sampled worldwide populations of these taxa, generated a multi-locus sequence data set to reconstruct evolutionary relationships, and explored phylogeographic patterns Our results reveal extensive phylogenetic structure in both P crenata and P decipiens Striking phylogeographic patterns were observed for P crenata, with populations from distinct geographic regions (eg, western North America, South Africa, and the Middle East) belonging to well-separated monophyletic lineages In addition, South African populations of P crenata were recovered in three well-supported sub-clades While well-supported phylogenetic substructure was also observed in P decipiens, nearly all lineages were comprised of specimens collected from intercontinental populations However, all Australian populations of P decipiens were recovered within a single well-supported monophyletic clade The taxon P saviczii was recovered as a well-supported monophyletic group nested within the core group of P decipiens Here we discuss biogeographic patterns and potential factors driving the spatial distribution of lineages within the P crenata and P decipiens groups Given that arid and semiarid areas, the predominant environments for BSCs, occupy approximately one third of the Earth’s total land area, our study has important implications for understanding factors influencing the distribution of lichens in these important communities. June, 2017.
  • Cook M, Leavitt SD, StClair LL. Disjunct intercontinental populations of lichen-forming fungi – relicts of past continuous distributions or the result of long-distance dispersal?. Botany 2017. Floristic similarities in widely disjunct geographic regions have long fascinated biologists In North America, striking examples include Asa Gray’s famous connections between eastern North America and eastern Asia and the Altai-Rocky Mountain floristic connections More recently, botanists have examined compelling examples demonstrating disjunct distribution patterns between the Intermountain West of North America and Central Asia for many species These similarities are especially apparent in alpine, subalpine, and desert-steppe floras However, due to limited information on the temporal scale of divergences and genetic population structure for most lineages, the origin of widely disjunct populations in the intermountain western region of North America (Intermountain West) and Central Asia remains unclear Two general explanations prevail: 1) Species with disjunct populations had more contiguous distributions during the Tertiary period, with connections between North America and Asia, eg, via Beringia or the North Pole by way of Greenland In fact, the Rocky Mountain flora has been characterized as “a microcosm of its rich Middle Asiatic counterpart,” with the present disjunctions representing relictual populations of a once widely distributed Oroboreal flora The alternative explanation: 2) Is that disjunct populations are a result of long-distance dispersal events or migration into ecologically similar, disjunct regions Using a number of lichen-forming fungal species common to western North America and Central Asia, we have investigated the hypothesized roles of long-distance dispersal vs relicts of past continuous distributions for explaining contemporary distribution patterns In many cases, molecular sequence data support broad, intercontinental lineages of lichen-forming fungal lineages with no evidence of phylogeographic differentiation among populations Furthermore, divergence time estimates indicate that a number of disjunct species of lichen-forming fungi share a most recent common ancestor well after the end of the Tertiary period Taken together, these results suggest that effective long-distance dispersal/migration during the Pleistocene played an important role in creating these impressive disjunct populations in the Intermountain West and Central Asia. June, 2017.
  • Wright B, Leavitt SD, StClair LL. Next-Gen Sequencing for Next-Gen Biomonitoring: Using a Community Metabarcoding Approach to Assess Species Diversity for Lichen-forming Fungi. Botany 2017. Lichens are commonly used in bio-monitoring research to assess ecological health under a range of different strategies, eg, assessing elemental accumulation patterns, investigating the presence or absence of indicator species, and comprehensive floristic inventories, etc Comprehensive lichen inventories at biomonitoring reference sites can provide important insights into potential impacts of disturbances by documenting overall diversity and the presence of indicator species (eg, pollution-tolerant or pollution-sensitive lichens), in addition to providing important information concerning community structure and species distribution patterns However, generating comprehensive lichen inventories is time and labor intensive, often requiring specialized professional researchers with diverse backgrounds and multiple sampling attempts Due to the limited number of specialists and challenges with generating objective species inventories, investigating alternative sampling strategies for compiling lichen inventories for biomonitoring research using lichens may improve efficacy and objectivity The aim of our study is to determine if a community DNA meta-barcoding approach can provide an objective cost- and time-effective alternative for generating reliable, comprehensive site-specific inventories for lichen-forming fungi We tested this strategy at a previously-established lichen biomonitoring reference site in the Great Basin, Nevada Here, we compare data from individual meta-community sampling efforts and different DNA extraction methods to the previously-established lichen inventory for this site Libraries from PCR amplicons of the ITS2 region of the internal transcribed spacer region from meta-community samples were sequenced on the Illumina MiSeq platform These results were compared to the initial, traditional inventory, and DNA sequence data generated from vouchered specimens Based on our results, we discuss the strengths and limitations (including cost, time, and consistency of results) of using a community metabarcoding approach for assessing biodiversity for lichen-forming fungi. June, 2017.
  • Distefano I, Clement WL, Esslinger T, Leavitt SD, Lumbsch HT. Phylogeny informs evolutionary classification of Physcia (Physciaceae), a diverse genus of foliose lichens. Botany 2017. Molecular data have dramatically increased our understanding of evolutionary relationships and species delimitation of groups of organisms distinguished by few defining morphological features, including lichen-forming fungi Physcia (Physciacese) is a foliose genus of rosette lichenized fungi with a cosmopolitan distribution Historically, Physcia species have been difficult to circumscribe due to both morphological similarities and plasticity of traits For example, since many species are largely indistinguishable in growth morphology and chemical components, reproductive strategies are instead commonly used to distinguish numerous species Recent studies have utilized genetic data to better understand species boundaries in Physcia and uncovered previously overlooked species-level diversity in the genus Consequently, number of described species within Physcia has increased from 50 to over 70 in the past decade alone However, the North American Physcia species remain poorly studied, with many open questions regarding species diversity and relationships Here, we present an expanded phylogeny that now includes an additional 150 accessions of 25 species of North American Physcia Eurasian Physcia accessions from Genbank were also included to investigate the potential of phylogeographic patterns within the genus Using this, the most comprehensive Physcia dataset to date, we infer evolutionary relationships among described taxa and study the evolution of the morphological characters often used to delineate Physia species We recovered seven major clades Few species were recovered as monophyletic, and our results indicate that robust species delimitation studies and taxonomic revisions will be required to adequately characterize diversity in this group Furthermore, our results cast doubt on the utility of using reproductive patterns and morphology to distinguish species Our phylogeny provides an important foundation to assess species boundaries, phylogeographic patterns, character evolution, and taxonomy of North American Physcia species. June, 2017.
  • StClair LL, Leavitt SD. Using Lichens to Document the Effects of Human-related Disturbance to Natural Landscapes. Botany 2017. Air quality biomonitoring efforts, spanning more than 25 years in the Intermountain Western United States, are being used to document air pollution-related impact on USDA Forest Service managed wilderness areas Sources of air pollution range from fossil fuel processing and combustion to landscape level disturbance in conjunction with extraction and processing of mineral resources to increasing levels of wildfire activity Elevated levels of Copper (≥ 34 ppm) and Aluminum (≥ 2500 ppm) as well as high Cu/Zn ratios (≥ 060) based on the analysis of two sensitive lichen indicator genera Usnea spp and Xanthoparmelia spp, collected in 2014 from the Gila and Blue Range wilderness areas in New Mexico, suggest impact from local open-pit Copper mining and ore processing activity in southwestern New Mexico The two wilderness areas are located northwest of the mining operations with prevailing wind patterns moving air from west to east However, late afternoon monsoonal storms, from July through October, result in seasonal wind patterns that move air and moisture from the Gulf of Mexico and Gulf of California across the open-pit Copper mines in southwestern Mexico into both the Gila and Blue Range wilderness area airsheds Differences in air pollutant accumulation patterns between fruticose (Usnea spp) and foliose (Xanthoparmelia spp) lichen growth forms suggest that, where possible, use of both growth forms for accurately documenting a more robust pattern of air pollutant accumulation is advisable. June, 2017.
  • Huang J, Nelsen M, Kraichak E, Leavitt SD, Lumbsch T. Accelerated Diversification in Lichen-Forming Fungi after the K-Pg Boundary. Evolution 2017. June, 2017.
  • Leavitt SD, Kirika PM, Paz GAd, Lumbsch HT, Diversification in the world’s most diverse genus of lichen-forming fungi, Xanthoparmelia (Ascomycota) . XXI AETFAT Congress. Diversification dynamics of major radiations in symbiotic fungi remain woefully underexplored Extending the analysis of speciation dynamics to species-level radiations representing non-model groups is important to understand factors driving diversification in ecologically important and understudied regions Here we investigate diversification dynamics in the most diverse clade of lichen-forming fungi, Xanthoparmelia (Ascomycota), with a particular focus on the radiations in East Africa Xanthoparmelia species occur worldwide in semi-arid and arid habitats Over 800 species are currently recognized, with two main centers of distribution, Australia and southern Africa The mechanisms of how Xanthoparmelia became extremely successful in these habitats are still not clear In general, a major period of diversification in Xanthoparmelia coincides the expansion of drylands during the Oligocene-Miocene transition, with a few known lineages dominated by much more recent diversification histories Diversity in Xanthoparmelia is not equally distributed across geographic regions, with disproportionately high diversity in Africa and Australia Can this variation be accounted for by clade age (has Xanthoparmelia been present in Australia and Africa longer than other regions?) or do increased rates of speciation explain these differences? To investigate these questions, we sampled Xanthoparmelia species from three major regions: (i) Australia, (ii) east Africa, and (iii) North America We investigate, diversity, biogeography, and speciation dynamics of independent Xanthoparmelia radiations in distinct geographic regions using multi-locus and phylogenomic data Our results highlight the important role of sampling Xanthoparmelia populations in Africa to understand diversity and diversification in this hyperdiverse genus of symbiotic fungi . May, 2017.
  • Leavitt SD. Exploring the possibility of multiple Trebouxia lineages in individual lichen thalli using next-generation sequencing. Meeting of the Trebouxia-Working Group. Microbial symbionts are instrumental to the ecological and long-term evolutionary success of their hosts, and the central role of symbiotic interactions is increasingly recognized across the vast majority of life Lichens provide an iconic group for investigating patterns in species interactions; however, the iconic perspective of lichen thallus comprised of a single mycobiont associating with a single photobiont has recently been challenged The occurrence of multiple photobiont specieslevel lineages occurring in individual lichen thalli - intrathalline photobiont plurality - has been detected across a number of lichens groups In this study, we implement a shotgun sequencing approach to characterize potential intrathalline photobiont plurality in members of Lecanoraceae and Parmeliaceae We demonstrate that high throughput sequencing provides a powerful tool for assessing intrathalline algal diversity, in addition to generating phylogenomic datasets for inferring evolutionary relationships. September, 2016.
  • Leavitt SD. Inferring a phylogenetic hypothesis for Trebouxia to better characterize diversity in this important photobiont genus. Meeting of the Trebouxia-Working Group. The algal genus Trebouxia is comprised of diverse symbiotic algae, representing perhaps the most commonly associated lichen photobiont Research into this important algal genus has provided vital perspective into symbiotic interactions in lichens, and symbiosis in general However, in spite of the central role of Trebouxia in many lichen symbioses, a robust phylogenetic hypothesis of relationships has not yet been reconstructed for the genus In this study, we assembled Trebouxia sequence data from over 1000 specimens (lichens and pure algal cultures) representing the currently known phylogenetic diversity in the genus We generated sequence data from the nuclear ribosomal ITS, a fragment of the protein-coding rbcL chloroplast gene, and a fragment of the mitochondrial COX2 gene Our phylogenetic reconstructions support four major clades previously recognized in Trebouxia and the monophyly of many of the candidate species level lineages This study provides a key foundation for advancing our understanding of evolutionary processes, patterns of species interactions, and species delimitation in Trebouxia. September, 2016.
  • Leavitt SD. Insight into diversification of lichen-forming fungi in western North America: from the Neogene through the Quaternary. LICHENS IN DEEP TIME: The 8th IAL Symposium. August, 2016.
  • Widhelm T, Egan RS, Bertoletti FR, Asztalos MJ, Leavitt SD, Lumbsch HT. Picking holes in traditional species delimitations: an integrative taxonomic reassessment of Parmotrema perforatum group (Parmeliaceae, Ascomyota). LICHENS IN DEEP TIME: The 8th IAL Symposium. Accurate species delimitation is important since species are a fundamental unit in biological research In lichenized-fungi, species delimitation has been difficult due to a lack in taxonomically important characters and due to the limits of traditional, morphology-based species concepts We apply an integrative approach to reassess the taxonomy of the Parmotrema perforatum group; six closely related species divided into three species pairs, each pair comprising one apotheciate (sexual) and one sorediate (asexual) species Each pair is further characterized by a distinct combination of secondary metabolites Species boundaries were reexamined using an integrative approach incorporating morphological, chemical, and molecular sequence data to delimit species boundaries Phylogenies were inferred from a seven-locus DNA sequence dataset using both concatenated gene tree and coalescent-based species tree inference methods We employed multispecies coalescent method implemented in the program BP&P to validate candidate species Micromorphological measurements of conidia were found to be congruent with clusters found in the phylogenetic analyses, uncovering unknown evolutionary relationships Each approach that we applied to the P perforatum group consistently recovered four of the currently circumscribed species P perforatum, P hypotropum, P subrigidum, and P louisianae, while P preperforatum and P hypoleucinum were consistently interpreted as conspecific. August, 2016.
  • Leavitt SD, Grewe F, Lumbsch HT. Recombination and horizontal gene transfer in mitochondrial genomes of the genus Rhizoplaca (Lecanoraceae). LICHENS IN DEEP TIME: The 8th IAL Symposium. August, 2016.
  • Lücking R, Hodkinson B, Leavitt SD. The classification of the lichen fungi: Assessment of the completeness and updated statisitcs of class-, order-, family- and genus-level species richness. LICHENS IN DEEP TIME: The 8th IAL Symposium. August, 2016.
  • Mark K, Saag L, Leavitt SD, Nelsen MP, Will-Wolf S, Nelsen MP, Tõrra T, Saag A, Randlane T, Lumbsch HT. Untangling Usnea: multi-locus concatenated and coalescent-based analyses reveal recent diversification history and clusters of mixed morphospecies in the section Usnea. LICHENS IN DEEP TIME: The 8th IAL Symposium. While the cosmopolitan genus Usnea (Parmeliaceae) is well known and easily recognized by the usually yellowish beard-like thallus with central cord, delimitation of many Usnea species is difficult due to the high variation and complexity of diagnostic characters We assessed the monophyly of 18 species from section Usnea occurring in North America and Europe, including sorediate and sexually reproducing taxa with both pendent and shrubby thalli Six nuclear markers (ITS, IGS, beta-tubulin, MCM7, RPB1 and RPB2) were sequenced for 144 samples All analyzed loci showed weak genetic structure and short branch lengths in single-locus topologies Concatenated, multi-locus analyses conducted in Bayesian and maximum likelihood frameworks, as well as coalescent-based species delimitation and species tree methods, recovered several distinct clades, some represented traditional morphology-based species (Usnea cavernosa, U praetervisa, U silesiaca, U wasmuthii), while others formed clusters of two or more species (Usnea florida – U subfloridana, U fulvoreagens – U glabrescens, U barbata – U chaetophora – U dasopoga – U diplotypus, U barbata – U intermedia – U lapponica – U substerilis) We illustrate how the utility of some traditionally used characters in Usnea species identification varies in the light of the genetic data. August, 2016.
  • Will-Wolf S, Mark K, Saag L, Leavitt SD, Nelsen MP, Tõrra P, Saag A, Randlane T, Lumbsch HT. Potential studies on ecological patterns are suggested for the recently diversified Usnea section Usnea . Botany 2016. July, 2016.
Steve Leavitt