Cloud forest passalids: An evolutionary study of the genus Yumtaax (Coleoptera: Passalidae)
Abstract
Temperate forests are hotspots of biodiversity and some of the most threatened ecosystems of
Mesoamerica. Understanding the biogeographical patterns of species inhabiting these forests is a
crucial part of designing effective conservation strategies. Yumtaax Boucher is a genus from the
family Passalidae distributed in the Temperate Serrias of Mexico with a high degree of
endemism. Species in the genus have had an unstable taxonomic history, and a phylogenetic
approach to understand species delimitations and relationships between these species is
necessary. This study reconstructed the molecular phylogeny of 6 operational taxonomic units
(OTUs) in the genus, using parsimony and Bayesian analysis of DNA sequence data from the
nuclear gene region 28S, and the mitochondrial gene regions 12S and Cytochrome Oxidase I
(CO1). Analyses recovered two well supported Yumtaax clades (Y. laticornis clade and Y.
imbellis clade), but not a monophyletic Yumtaax. The number of species in the genus was
increased from six to nine species due to discovery of two separate, evolutionary lineages
(=species) of Yumtaax recticornis and the presence of two undescribed morphotypes that are
included within the well supported Yumtaax clades. Gene performance for supported taxonomic
groups (=lineages, clades) was measured and, based on these data, it is possible to test species
delimitation within the family Passalidae using 12S and CO1 mitochondrial sequences. Further
studies need to be conducted to resolve generic level relationships. Species of Yumtaax are
distributed in four forest types (oak forest, pine forest, pine-oak forest, and cloud forest) of the
Mexican mountains; most of the eastern species (except Yumtaax LCM) are part of the Yumtaax
laticornis clade, and the southern and western species are part of the Yumtaax imbellis clade.
Species of Yumtaax are distributed in habitats that represent unique genetic reservoirs and that
are threated by habitat loss. Resulting data are used to inform management strategies that are
required for conservation of the Mexican temperate forests.
Description
Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences