Evolution and phylogeny of basal winged insects with emphasis on mayflies (Ephemeroptera)

• Main Author: Ogden, Thomas H.
• Format: Text
• Language: unknown
• Published: BYU ScholarsArchive 2004
• Subjects: Ephemeroptera; Odonata; phylogeny; systematics; evolution; mayflies; molecular phylogeny; evolution of flight; origin of wings; pterygota; mandibular tusks; sensitivity analysis; direct optimization; Ephemerellidae; Pannota; Biology; Antarc*; Antarctica
• Online Access: https://scholarsarchive.byu.edu/etd/207; https://scholarsarchive.byu.edu/context/etd/article/1206/viewcontent/ETD_CISOPTR_226.pdf

Ephemeroptera (mayflies) is a monophyletic group of semi-aquatic pterygote insects, comprising 3083 species, 376 genera, and 37 described families and are present on all continents, excluding Antarctica, being associated with freshwater and brackish water habitats. The order is unique among pterygote insects in possessing functional wings at the penultimate molt (subimago stage), prior to the full development of genitalia; in all other insects the presence of functional wings occurs only after the final molt. The purpose of this dissertation is to use molecular and morphological data, in order to investigate the position of the order Ephemeroptera among other insect orders, the higher-level relationships among the major lineages of mayflies, and a detailed analysis of the family Ephemerellidae. Ephemeroptera has been considered by many to be sister to Odonata + Neoptera although alternate hypotheses have been suggested. Data from three molecular loci ambiguously resolve basal pterygote relationships, however, total evidence analysis (combined molecular and morphological data) strongly supports the position of mayflies as sister to all other extant pterygotes. These results and methodologies were recently criticized, and, therefore, the response to the author is included following the manuscript. The phylogenetic relationships among mayfly families is debatable and in some groups unknown. Prior studies have produced phylogenies based on morphological characters mixed with intuition. The first molecular phylogeny for the Order Ephemeroptera is presented. The analyses include 31 of the 37 families, representing ~24% of the genera. The suborders Furcatergalia and Carapacea are supported as monophyletic while Setisura and Pisciforma are not supported as monophyletic. The evolution of the wings, mandibular tusks, burrowing lifestyle, and fishlike body are investigated. Topological sensitivity analysis is used as a tool to examine patterns concerning the stability of relationships across a parameter landscape, ...