The Evolution of Vertebrate Teeth: a Review and Phylogenetic Analysis Using Categorical Data
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The Evolution Of Vertebrate Teeth: A Review And Phylogenetic Analysis Using Categorical Data Item Type text; Electronic Thesis Authors Lee, Davis Min Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 28/09/2021 19:42:44 Item License http://rightsstatements.org/vocab/InC/1.0/ Link to Item http://hdl.handle.net/10150/632849 THE EVOLUTION OF VERTEBRATE TEETH: A REVIEW AND PHYLOGENETIC ANALYSIS USING CATEGORICAL DATA By DAVIS MIN LEE ____________________ A Thesis Submitted to The Honors ColleGe In Partial Fulfillment of the Bachelors deGree With Honors in BioloGy THE UNIVERSITY OF ARIZONA M A Y 2 0 1 9 ApProved by: ____________________________ Dr. John Wiens DePartment of EcoloGy and Evolutionary BioloGy Lee 1 Table of Contents ABSTRACT .................................................................................................................................................................. 3 INTRODUCTION ........................................................................................................................................................ 4 MATERIALS AND METHODS ................................................................................................................................. 6 RESULTS ...................................................................................................................................................................... 9 LOCATION ........................................................................................................................................................................................................... 9 REPLACEMENT ................................................................................................................................................................................................. 11 ATTACHMENT .................................................................................................................................................................................................. 12 DISCUSSION ............................................................................................................................................................. 14 CONCLUSION ........................................................................................................................................................... 19 REFERENCES ........................................................................................................................................................... 20 APPENDIX 1: CHARACTER MAPS ...................................................................................................................... 26 FIGURES 1-11: LOCATION ........................................................................................................................................................................... 26 FIGURES 12-15: REPLACEMENT ................................................................................................................................................................ 32 FIGURES 16-21: ATTACHMENT .................................................................................................................................................................. 34 APPENDIX 2: SUPPLEMENTAL TABLES .......................................................................................................... 37 SUPPLEMENTAL TABLES 1.1-1.3: LOCATION ....................................................................................................................................... 37 SUPPLEMENTAL TABLES 2.1-2.3: REPLACEMENT AND ATTACHMENT ....................................................................................... 40 2 Lee 3 Abstract The crucial importance in phylogenetic analyses lies in their ability to detail the evolution of living organisms by comparing homologous traits that arose over time. Through them, these analyses not only tell what organism was derived from what, but also reveal how environmental circumstances drove the formation of characteristics favorable for that time. Though teeth have been a crucial component in phylogenetic analyses, they rarely are the key consideration; and in cases in which they are, the study is isolated in a single clade of organisms. This report details a broad review of current knowledge of vertebrate teeth from Agnatha to Mammalia, specifically focusing on their location, replacement, and attachment. Furthermore, this report also includes an analysis of a character map made from the current information on the teeth characteristics listed and on established vertebrate phylogenies. It is the hope of this author that by exploring the evolution of vertebrate teeth, a greater understanding of how teeth came to be, what they can become, and what could be done for man’s may be garnered by those who wish to know. 4 Introduction Vertebrate evolution has been and continues to be researched and expanded upon for the past few decades. With advancements in multiple scientific fields such as paleontology, genetics, comparative anatomy, statistics, and phylogenetics, the world of vertebrate evolution—and evolution, in general—is rapidly expanding as researchers of those many fields integrate and assimilate their data to discover more wonders of this planet. Even in recent decades, many have explored vertebrate evolution in various ways. Blomme et al. (2006) traced genome evolution over the course of 600 million years, analyzing ancestral genes and the importance of gene duplication in the rise of complex vertebrates; Mindell and Honeycutt (1990) studied the exceptional possibility of utilizing ribosomal RNA to create a vertebrate phylogeny; and Romer (1967) summarized the near entirety of vertebrate origins and speciation. Though broad vertebrate evolution has been extensively researched, teeth (and specifically phylogenetics of teeth) have not been as explored. Teeth and their many variations have been a crucial element in paleontological and biological research in vertebrates for many years (Owen 1840). Current research on teeth is still voluminous, but the vast majority tends to focus on singular characteristics such as tooth location, attachment, replacement, genetics, and shape. For example, Davit-Beal et al. (2009) researched teeth loss in tetrapods by reviewing current knowledge on teeth genetics and the fossil record Smith and Johanson (2003) both studied the presence of teeth in derived placoderms known as athrodires through comparative anatomy, but they solely focused on athrodires, only referencing other vertebrates rather than giving them full analyses as well. Secondary sources such as Berkovitz and Shellis’s The Teeth of Non-Mammalian Vertebrates (2017) appear to be the few that analyze physical characteristics of teeth across all vertebrates as well as more microbiological ones. Lee 5 Phylogenetic analysis on teeth are of similar flavor to the more anatomical research. Smith and Coates (1998) investigated the origins of teeth in vertebrates by analyzing denticles and odontodes, and their phylogenetic analyses revealed that teeth may have been formed deep within vertebrate diversification as an intricate modification to non-growing odontodes. However, though they give suggestions and developmental models on how this new fact translates to the evolutionary biology of remaining vertebrates, they ultimately leave the task of further exploration to others. Fink (1981) also conducted phylogenetic research on vertebrates, but he focused specifically on tooth attachment in Actinopterygii. Similar treatment was given to hominids (Read 1975) and Amphibia (Parsons and Williams 1962), and any dental-based phylogenetic research focused on either one character, one clade, or one of each. For this thesis, a comprehensive, dentition-based review of all major classes and superclasses in vertebrates was conducted; and a character matrix and map of those classes were formed based on the information found in the review and on an appropriate phylogenetic tree. Characters involved in the making of the matrix and map included location, degree of replacement, and mode of attachment since all of these have been thoroughly covered by others and are easily quantifiable compared to others. This research project ultimately attempts to ascertain how these three characters influenced speciation over evolutionary time. Through this thesis, the details of dental evolution may be elaborated, and further endeavors to analyze the whole of vertebrate dentition may be sparked. 6 Materials and Methods With academic websites (Google Scholar, National Center for Biotechnology Information, ScienceDirect, Web of Science, and JSTOR), primary and secondary sources pertaining to the location, presence of differentiation, degree of replacement, shape, and type of attachment of teeth for a vertebrate class or order were searched and collected. Phrases such as “Chondrichthyes teeth replacement” and “Amphibia teeth homodont/heterodont” were used in the websites to find said sources. After appropriate sources were obtained, any information that they had pertaining to the five aforementioned character categories were noted and arranged in a character matrix via