Invertebrates 2 Arhropoda Echinodermata Chordata Cnidaria Nematoda Mollusca Porifera Annelida Platyhelminthes Cladogram of Phyla covered in Bio 11 Cladograms Cladograms Cladograms are constructed using a method known Cladograms are evolutionary tree diagrams that as ‘cladistics’. This method analyzes a collection show relationships based on synapomorphies of heritable character data compiled by a (shared-derived characters). researcher (morphology and/or DNA). This Shared-derived characters method groups taxa based on the number of Synapomorphies characters that they share with one another. Homologous characters characters that are shared by two or more groups which originated in (and were derived from) their immediate (last) common ancestor. Cladograms Cladistics example Cladograms are evolutionary tree diagrams that show relationships based on synapomorphies (shared-derived characters). Fly Fish Wolf Gorilla Human Heterotroph Heterotroph Heterotroph Heterotroph Heterotroph NOT: Chitin Vertebrae Vertebrae Vertebrae Vertebrae Antenae Eye Eye Eye Eye Homoplasy Compound eye Fins Hair Hair Hair 6 legs Scales 5 toes 5 toes 5 toes Analagous characters eggs 4 legs 2 legs+2 arms 2 legs+2 arms Opposable thumb Opposable thumb characters that look similar or have similar fucnctions, but are not derived from a common Homoplasy ancestor. Analogous characters Body Symmetry and Cephalization General Characteristics 1. Body Symmetry 2. Cephalization 3. Type of Gut 4. Type of Body Cavity 5. Segmentation Radial – body parts are Bilateral – right half and left half arranged regularly are mirror images. around a central axis. Anterior/Posterior – head/tail (example: sea anemone) Dorsal/Ventral – back/stomach Examples of Body Symmetry Echinoderm symmetry Radial Bilateral What about sea stars and sea urchins? As adults they have pentameral symmetry which is a form of radial symmetry, but their larvae show bilateral symmetry and molecular data indicates that their ancestors had bilateral symmetry. So we consider them to be bilaterians. Types of Guts Cephalization Sac-like Gut Tube-like Gut Bilateral organisms have developed a head in the anterior (front) end. This may have been favorable when moving forward and being able to detect and eat what’s in front of them. Many sensory and nerve cells Mouth Anus have become concentrated in the head. Single opening for Complete gut with mouth ingesting food and and anus. Food travels one- excreting wastes. way through the organism. Types of Body Cavities in Animals Types of Body Cavities in Animals Coelom - Lined body cavity Acoel - no body cavity Pseudocoel - unlined body cavity Segmentation Fossils Repeating series of body units that may be Fossile evidence has provided a greart deal of quite different. information about the origins of extant taxa. Examples: Segments of an earthworm are similar. Segments of a crustacean are different (lobster, insect). Ediacaran Fossils 600-542 million years Also called “Vendian” Ediacara Hills, Australia South Australia Spriggina Dickensonia Burgess Shale Ediacaran Assemblage • Yoho National Park • Canadian Rockies • ~540 mya Burgess Shale View from the Quarry Working the Burgess Shale Helena Walcott & family, ca. 1910? Charles Walcott in his seventies Royal Ontario Museum camp, August 2000, near Walcott’s campsite Burgess Shale Edge of the Quarry Discovery of Burgess Fossils Walcott’s Field Notes Burgess Shale Burgess Shale Slabs Ready to Split for Fossils Freshly Exposed Fossils Prepared Burgess Fossils Burgess Animals Arthropoda Trilobite Canadia Canadaspis Sanctacaris Anomolacarus Yohoia Annelid Arthropod Polychaete worm Marella Opabinia Figure from: Starr, C. (2000). Biology, Concepts and Applications. Brooks/Cole. Burgess Animals Burgess Animals Weird Phyla Onychophora Chordata Annelida Nectocaris Hallucigenia Canadia Dinomischus Wiwaxia Pikaia Aysheaia The Burgess Sea Arhropoda Echinodermata Chordata Cnidaria Nematoda Mollusca Porifera Annelida Platyhelminthes Cladogram of Phyla covered in Bio 11 Figure from: Starr, C. (2000). Biology, Concepts and Applications. Brooks/Cole. Origin of Multicellularity Key Points for Each Phylum: Animals • Recognize them choanoflagellate-like protists • Where they fall in the overall phylogenetic tree Two hypotheses 1. Ciliates • General Body Plan: symmetry, gut, coelom, skeleton One cell, many nuclei 2. Colonies • General lifestyle Colonies of cells that became specialized for certain tasks Porifera Porifera Porifera Cnidaria Cnidaria Cnidaria symmetry symmetry Bilateral Bilateral Platyhelminthes Platyhelminthes Platyhelminthes Snails, Octopus, squid, clams,chitons, nudibranchs clams,chitons, squid, Snails, Octopus, • system organ simplest •Tissues • symmetry Bilateral • organs or tissues no • nosymmetry • Basalto all animals • system Organ • types tissue many • symmetry Bilateral Nematoda Flatworms Nematoda Sponges Nematoda Mollusca Mollusca Mollusca Annelida Annelida Annelida Arhropoda Arhropoda Arhropoda Echinodermata Echinodermata Echinodermata Chordata Chordata Chordata Porifera Porifera Porifera Cnidaria Cnidaria Cnidaria symmetry symmetry Bilateral Bilateral symmetry Radial Radial Platyhelminthes Platyhelminthes • organs No • tissues Simple • symmetry Radial anemones sea corals, fish, Jelly Platyhelminthes • system Organ •Tissues • symmetry Bilateral • system Organ • tissue types Several • symmetry Bilateral Segmented worms, Earthworm worms, Segmented Nematoda Nematoda Nematoda Roundworms Mollusca Mollusca Mollusca Annelida Annelida Annelida Arhropoda Arhropoda Arhropoda Echinodermata Echinodermata Echinodermata Chordata Chordata Chordata Arhropoda Arhropoda Echinodermata Chordata Echinodermata Chordata Cnidaria Nematoda Mollusca Cnidaria Nematoda Mollusca Porifera Annelida Porifera Annelida Platyhelminthes Platyhelminthes Bilateral Bilateral symmetry symmetry Crustaceans, Insects Starfish, sea urchins, sea cucumbers • Bilateral symmetry • Bilateral symmetry •Tissues •Tissues • Organ system • Organ system Porifera (Sponges) Success in Simplicity • No symmetry, tissues, or Arhropoda Echinodermata Chordata Cnidaria Nematoda Mollusca Porifera Annelida Platyhelminthes organs • Abundant since Precambrian • 8000 species today • “Filter” food from the water • Sessile adults Bilateral symmetry • Silica spicules •General lifestyle: Marine filter feeders Mammals, reptiles, birds, fish • Bilateral symmetry • Complex Tissues • Complex organ systems Porifera Structural Elements of Sponges A sponge releasing a cloud of sperm Most live in coastal, shallow water marine environments Some deep ocean or fresh water Hermaphrodites that reproduce sexually (most species) Sperm in water, but eggs retained until fertilized Swimming larval stage Spicule types Sponges – Skeletal Elements Sponges Venus’s flower basket (Euplectella) Tethya aurantia Figure 23.7 (c,d) from page 361 of your text puffball sponge Sponges Sponges Acarnus erithacus Spheciospongia confoederata red volcano sponge moon sponge Sponges Sponges Coral Reef Spheciospongia confoederata close-up Vase Sponge moon sponge Phylum Cnidaria – anemones, corals, jellies 1. Key Innovations are radial symmetry and Arhropoda Echinodermata Chordata Cnidaria Nematoda Mollusca Porifera Annelida Platyhelminthes a tissue-level of organization (still no organs) 2. Diploblastic – have only two embryonic tissues (ectoderm and endoderm) Radial 3. Have a sac-like gut symmetry 4. Two body forms – polyp and medusa polyp is sessile and benthic, medusa is planktonic 5. Carnivores with one gut opening Jelly fish, corals, sea anemones 6. Reproduce sexually and asexually (budding) Cnidarian Reproduction Cnidarian Body Forms reproductive polyp female medusa male medusa ovum sperm feeding zygote polyp one branch planula branching polyp polyp medusa from a mature forming colony Cnidarians Phylum Cnidaria Cnidocytes Hollow thread Delivers venom Trigger Cells containing (cnidocil) a stinging Barbed tube structure (nematocyst). nematocyst Cnidocyte (cell) Sea wasp warning sea wasp warning Cnidarians - cnidocysts Cnidarians hydroid Jellyfish stings Cnidarians Cnidarians Lytocarpus philippinus stinging hydroid Millepora –fire coral Cnidarians Cnidarians Portuguese Man O’ War (Physalia physalis) Millepora – fire coral close-up Cnidarians Cnidarians close-up of tentacles of Portuguese Man O’ War (Physalia physalis) Urticina lofotensis rose colored anemone Cnidarians Cnidaria coral skeletons corals from the Great Barrier Reef Cnidarians Cnidarians Tubastrea tropical coral cup coral close-up Cnidarians Cnidarians symbiotic zooxanthellae (dinoflagellate) in coral tentacle Echinophyllia aspera (gray coral) close-up Cnidarians Cnidarians soft coral gorgonian (sea fan) Cnidarians Cnidarians notice polyps gorgonian close-up (sea fan) gorgonians (sea fans) Cnidarians Cnidarians Chrysaora fuscescens Sea nettle jelly Chrysaora fuscescens sea nettle jelly Cnidarians Cnidarians Chrysaora (Pelagia) colorata Purple-striped jelly Chironex fleckeri sea wasp Exam on Friday! We will have fewer questions! Review session tonight at 5:30 in 2301 Tolman..