WILD 114 INTRO ZOOLOGY Lecture 1 – Why Study Zoology / Animal Classification READING: Miller Chapters 1 and 7 January 7, 2019 Goals for Today: • Why Study Zoology? • What’s the big deal with evolution? • How are Zoology and Ecology Related? • How do we classify animals? Why study Zoology? Zoology includes the study of: • Mammology – the study of mammals • Herpetology – the study of reptiles • Ichthyology – the study of fish • Entomology – the study of insects • Ornithology – the study of birds • Carcinology – the study of crustaceans • Annelidology – the study of worms Zoology also evaluates extinct animals…. Anatomy Cytology Embryology Zoology leads to specialization Genetics Histology Molecular Biology Physiology Systematics Pause and Reflect Metathinking Why study zoology? Goals for Today • Why Study Zoology? • What’s the big deal with evolution? • How are Zoology and Ecology Related? • How do we classify animals? Evolution Defined • Organic evolution is a change in the genetic makeup of populations of organisms over time. It is the source of animal diversity, and explains family relationships within animal groups. Macro Evolution and Controversy • Macro evolution is a theory that asserts that positive mutations coupled with geologic time can result in species that are entirely new or different from the original ancestor. Evolution….a tree or a net? The Net Mitochondrial DNA Evolution and Relatedness Figure 1.4 Hierarchy of relatedness. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. At the Domain level there is little relatedness between Domain and Species. Relatedness increases as you go down the pyramid Taxonomy • The scientific classification of animals based upon shared genetic traits helps scientists sort out “who is who”. • This is particularly important when dealing with closely related animals like African Cichlids African Cichlids Pause and Reflect…. Metathinking What did we learn about evolution? Goals for Today • Why Study Zoology? • What’s the big deal with evolution? • How are Zoology and Ecology Related? • How do we classify animals? • Overpopulation Zoology and Ecology • Food • Air • Water • Oil • Timber World Resources Extinction Rates Goals for Today • Why Study Zoology? • What’s the big deal with evolution? • How are Zoology and Ecology Related? • How do we classify animals? Taxonomy reflects phylogeny….. Classification of Organisms • Systematics or taxonomy • Study of the kinds and diversity of organisms and of the evolutionary relationships among them Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. • In the 18th century, Carolus Linnaeus (Carl von Linne) published a system of taxonomy based on resemblances • Two key features of his system remain useful today: • two-part names for species • and hierarchical classification A Taxonomic Hierarchy • Taxon • Any grouping of animals that shares a particular set of characteristics • Taxonomic categories • Hierarchically arranged (broader to specific) • Domain, kingdom, phylum, class, order, family, genus, species • Above species level there are no definitions for each category Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Examples: Taxa = animals that share a similar trait Modern Taxonomy Hierarchical classification system Taxa – Major groupings or categories – Nested set of increasing inclusiveness Domain Share least DNA Kingdom Phylum Class Order Family Genus Species Mnemonic exercise Share most DNA • Simply put- two names • Genus, species • Latin • Universal Binomial Nomenclature Binomial Nomenclature • No two animals can have the same scientific name • The two-part scientific name of a species is called a binomial • The first part of the name is the genus • The second part, called the specific epithet, is unique for each species within the genus • The first letter of the genus is capitalized, and the entire species name is italicized or underlined • Both parts together name the species Domains and Kingdoms • The highest levels of classification in the taxonomic hierarchy • Ribosomal RNA key to determining Kingdoms because it is an ancient molecule that changes slowly Figure 7.2 Three lineages of life. Horizontal gene transfer (HGT) common in early history of life and makes base of tree net-like Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. The Goal of Animal Systematics To group animals in a way that makes sense based on their genetic relatedness and shared characteristics….. but its not always easy •Is it a snake? •Is it a lizard? Look at this guy! •How do we decide? Two Methods to Classify Animals • Method 1 - Animal Systematics • Monophyletic – all animals in a group have once ancestor • Polyphyletic – all animals in a two separate groups have one ancestor • Parphyletic – all animals in two completely different groups may have one ancestory Which Kingdoms are usually considered monophyletic? Two Methods to Classify Animals • Method 2 Evolutionary Systematics • Homologies – traits of different animals are similar because they share a common ancestor • Analogies – traits of different groups of animals are similar because they adapted to similar environments. Two Types of Evolutionary Systematic Similarities Cladists vs. Taxonomists….the big rumble Cladistics explained Molecular Approaches to Animal Systematics • Relatedness of animals reflected in proteins and DNA • Nuclear and mitochondrial DNA • Ribosomal RNA Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. • Ribosomal RNA studies • Distant evolutionary relationships • Evolutionary conservation results in very slow rates of change (evolutionary conservation) Domains and Kingdoms • Three major lineages (Domains) • Eubacteria • Bacteria • Archaea • Extremophile microbes • Eukarya • Organisms with compartmentalized cells • Nuclear membranes separate transcription & translation • mitochondrial & chloroplast membranes compartmentalize energy processing Compare cladogram and phylogenetic tree 1. What kind of information is common to both representations? 2. How are the relationships between reptiles, birds, and mammals represented differently in the two figures? 3. How do the differences in question 2 above reflect differing approaches of phylogenetic systematics and evolutionary systematics? Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Another approach to organizing animals • Symmetry • Assymetry • Radial symmetry • Bilateral symmetry Asymmetry. Radial symmetry. Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Bilateral symmetry. Group exercise • Come up with 3 additional examples animals that exhibit: 1. Asymmetry 2. Radial symmetry 3. Bilateral symmetry And another method….cellular organization •Unicellular •Diploblastic •Triploblastic Pause and Reflect…..Metathinking How do we organize animals? Questions?