BIOL2151_Week1_Classification - How many of these animals...

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Unformatted text preview: How many of these animals can you name? (quiz yourself) BIOL2151 Animal Diversity Jeff Shimeta (coordinator) Dayanthi Nugegoda School of Applied Sciences 1 2 How many of these animals can you name? (a bit harder) How many of these animals can you name? (much harder) 3 4 Which animals are classified in the same phylum? Why? (you should know the answer by the end of the semester) Which animals are classified in the same phylum? Why? (you should know the answer by the end of the semester) 5 6 Which two animals are more closely related to each other than either is to the third? Which two animals are more closely related to each other than either is to the third? 7 Common ancestor of koala and wolf was more recent than the common ancestor of either of them and the shark. This should make intuitive sense to you. 8 Which two animals are more closely related to each other than either is to the third? Which two animals are more closely related to each other than either is to the third? 9 Most recent common ancestor. This may seem odd at first, but it is based on the same reasoning as the last example. They had an ancestor in common more recently than either of them had with the shark. 10 Your Instructor: Jeff Shimeta, Ph.D. Zoologist, Marine Ecologist Research Specialties •Ecology of aquatic protozoa and invertebrates •feeding and food-web interactions •influences of physical environment (flow, sediments) •environmental issues •Research projects •dispersal and settlement of invertebrate larvae •microscopic fauna and nutrient cycling in Port Phillip Bay •impacts of invasive salt marsh plants on coastal invertebrates •microscopic fauna in Victorian streams, and impacts from contaminants Lizard Island Field Excursion BIOL2061 10 Day Adventure Next Trip: July 2010 • Snorkel on the Great Barrier Reef daily. • Learn marine ecology and environmental problems of the reef. • Learn reef surveying methods. • Accommodation at the Lizard Island Research Station. • Day trip to the Daintree rainforest. More info and slideshow at Please see me if interested in research opportunities! http://www.lizardisland.rmitsciphoto.com 11 12 Animal Classification and Phylogeny 1 March 2010 BIOL2151 The Linnaean Classification System Question How and why are animals classified? Outline I. Linnaean classification. II. Phylogeny (evolutionary relationships). A. Cladograms (evolutionary trees). B. Monophyletic groups (clades). C.Cladograms of animals. III. Important characters for animal classification and phylogeny. A. Comparative morphology. B. Development. Kingdom Animalia Animalia Phylum Chordata Chordata Class Mammalia Mammalia Order Carnivora Carnivora Family Canidae Canidae Genus Canis Canis Species Canis familiaris Species Canis 13 14 The Linnaean Classification System Cladogram (phylogenetic tree) • One goal of classification is to aid study of evolutionary relationships among groups. • A cladogram depicts evolutionary relationships (phylogeny). • Taxa with the most recent common ancestor are the most closely related. "group" is called a taxon. (plural: taxa) plural: taxa) Kingdom Animalia Animalia Phylum Chordata plural: phyla Chordata plural: Class Mammalia Class Mammalia Order Carnivora Carnivora Family Canidae Canidae Genus Canis plural: genera Canis plural: Each "rank" or Species Canis familiaris Species Canis (The Latin Binomial) Binomial) • Always italicised or underlined. • Genus is capitalised, species not. • Can abbreviate (C. familiaris), only after full name is stated once. 15 time 16 A Family Tree for Comparison Amanda (grandmother) Components of a Cladogram extant species extinct species time Wayne (dad) Sandra (my aunt) Aaron (brother) Me Glenn (cousin) Carl (cousin) "Sister taxa:" those more closely related to each other than to any other taxa. • The sister taxon of C. draconoides is U. scoparia. • The sister taxon of P. platyrhinos is both C. draconoides is U. scoparia because they both have the same common ancestor with P. platyrhinos, i.e. their lineages diverged from P. platyrhinos at the same time. 17 18 Which features of the cladogram are most important for showing evolutionary relationships? Here are two alternative drawings of branches, but they show the same phylogenetic relationships (look at nodes). Grouping Taxa into Higher Levels (e.g. grouping genera into families) (Hickman Fig. 4.5) • Evolutionary relationships are revealed by the history (relative position in time) of common ancestors. • The order in which extant taxa are written across the top (left to right) is irrelevant. Monophyletic (a “clade”): includes most recent common ancestor and all of its descendants. According to the strict cladistic approach, only monophyletic groupings are valid, because the members are more closely related to each other than to any other taxa. Paraphyletic: includes most recent common ancestor but not all of its descendants. 19 Polyphyletic: does not include most recent common ancestor. 20 Example of a Traditional Taxon that is Paraphyletic Another Example of a Paraphyletic Taxon Family Pongidae Class Reptilia * Fix this by bringing birds into the Class Reptilia. * Fix this by bringing humans into the family with apes. 21 (Hickman Fig. 4.7) 22 A Comprehensive Cladogram of Animal Phyla Note: in this depiction, time runs from left to right. The Cladogram of Animal Phyla You Must Learn PROTOSTOME PHYLA Pl at ph yzo yl an a Lophotrochozoan phyla (Platyhelminthes, Annelida, Mollusca, Lophophorate phyla) Ecdysozoan phyla (Nematoda, Onychophora, Arthropoda) DEUTEROSTOME PHYLA (Echinodermata, Hemichordata, Chordata) ra ife or P ria da ni C Note: More detail will be added during the semester. (Valentine 2004) 23 24 The Cladogram of Phylum Chordata You Must Learn JAWLESS FISHES BONY FISHES TETRAPODS Evidence Used to Define Taxa and Construct a Phylogenetic Tree 1. 2. 3. 4. Comparative body architecture and morphology Development Gene sequences Fossil record Ur oc ho rd ata Ce ph alo ch or da ta My xin i Pe tro my zo nti da Ch on dri ch thy es Ac tin op ter yg Sa ii rco pte ryg ii Am ph ibi a AMNIOTES seg me 5c nte hor dm dat usc e tr les aits ver teb rae cra niu m jaw s swi mb lad der or l ung ma mm ary am gla nio nds tic tetr , ha egg apo ir d li mb s Synapomorphies (in blue): shared-derived characters that define a clade. 25 26 Comparative Body Architecture and Morphology 1. Levels of Organisation in Complexity Unicellular Cellular-level organisation (colonial or multicellular) Ma mm ali a Re pti lia Comparative Body Architecture and Morphology 2. Body Symmetry Tissue-level organisation Organ-level organisation Bilaterally symmetrical animals have: • Anterior/posterior, dorsal/ventral, and left/right sides. • Cephalisation (often): possessing a differentiated head with concentrated nervous tissue and sense organs. 27 Organ-system organisation (Hickman Table 3.1) (Hickman Figs 3.1, 3.2) 28 Comparative Body Architecture and Morphology 3. Number of Embryonic Tissue Layers None. Two (diploblastic): endoderm, ectoderm. Three (triploblastic): endoderm, mesoderm, ectoderm. Comparative Body Architecture and Morphology 4. Body Cavities of Triploblastic Animals between the Gut and Outer Body Wall. Pseudocoelomate (or "blastocoelomate"): Body cavity lined by mesodermally derived tissue on the outer side only. Sponge Sea anemone Flatworm (and almost all other animals) Acoelomate: No body cavity. Coelomate (or "eucoelomate"): Body cavity lined by mesodermally derived tissue on the outer and inner sides. (Hickman Fig 3.9) 29 30 Development: Protostomes vs. Deuterostomes Species Diversity Through Time • Four important differences between protostomes and deuterostomes. • Note for protostomes: • Item 1 applies only to the lophotrochozoan protostomes, not to the ecdysozoan protostomes (which have neither spiral nor radial cleavage). • Items 2-4 apply to all protostomes. (similar to Hickman Fig 3.8) 31 32 Species Diversity Through Time Terminology Linnaean classification (domain, kingdom, phylum, class, order, family, genus, species) Latin binomial taxon (taxa) phylogeny phylogenetic tree, cladogram node, branch extant, extinct sister taxa monophyletic, paraphyletic, polyphyletic synapomorphy, shared-derived character radial symmetry, bilateral symmetry cephalisation anterior, posterior, dorsal, ventral sagittal, transverse, frontal planes diploblastic, triploblastic acoelomate, pseudocoelomate (=blastocoelomate), eucoelomate (=coelomate) protostome, deuterostome 34 • • • • A few points about vertebrates and invertebrates: Are the vertebrates a phylum or part of a phylum? Are most animal species vertebrates or invertebrates? Do you think the traditional division between vertebrates and invertebrates is sensible or justified? Are vertebrates monophyletic? Are invertebrates monophyletic? 33 References Hickman, C.P. et al. 2009. Animal Diversity, 5th ed. McGraw Hill. Chapter 1 for review (not tested) Chapters 3, 4 Valentine, J.W. 2004. On the Origin of Phyla. University of Chicago Press. 35 ...
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This note was uploaded on 12/19/2010 for the course BIO 2151 taught by Professor Jeffshimeta during the Three '10 term at Royal Melbourne Institute of Technology.

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