Animal diversity 1 - Evolution What are the three domains of life? of the animal body plan Bacteria Archaea Key concepts for today Eukarya • Definition of an animal What are the kingdoms? • Major phyla, and their relatedness (where they are on a tree) Bacteria • Major stages in evolution of animal Arachaea body plan and where they occurred protists Plantae Fungi 1 Animalia 2 What features together define a Phylogenies of the deep roots of life are controversial member of the Kingdom Animalia? (not to memorize:) 2005 revision of Eukarya Multicellularity kingdoms: instead of three, six: four protist kingdoms, “Opisthokonta” (fungi + animals) In what Kingdom do animal-like single and “Archaeplastida” (plants) Among protist systematists, even this celled creatures belong? arrangement is controversial. “I’ve seen people throw things at each other” one of the Are all protists unicellular? authors says. What else is common to all animals? Your text book has a different arrangement of animal phyla. The one we will focus on today Heterotrophic life style is used in Lab 4 - learn this one rather than the one in the book. Heterotrophic? Autotrophic? Why can’t we reconstruct these ancient divisions with certainty? 3 2a What features together define a member of the Kingdom Animalia? Extracellular matrix (ECM) Multicellularity Made up of proteins and Heterotrophic life style glycoproteins And? Give animal cells and animals Extracellular matrix (ECM) structure - extra (outside) cellular (cells) matrix Hard stuff in bone, cartilage, forms (“stuff” or more precisely “substance soft barriers and filters around within which something originates, cells, e.g. gut linings develops, or is contained”) Same as a cell wall? 4 5 Page ‹#› What other traits do you associate Animal quiz: Are each of these with animals? animals? If so, what phylum? Why do they have them? Do all animals have them? 6 7 Animal quiz: Are each of these Animal quiz: Are each of these animals? If so, what phylum? animals? If so, what phylum? 8 9 Animal quiz: Are each of these Animal quiz: Are these animals? If animals? If so, what phylum? so, what phylum? 10 11 Page ‹#› Animal quiz: Are each of these Animal quiz: Are these animals? If animals? If so, what phylum? so, what phylum? 12 13 Today - evolution of the animal One hypothesis for evolution of body plan major animal phyla p. 52 of your lab manual 14 15 One hypothesis for evolution of One hypothesis for evolution of major animal phyla major animal phyla CNIDARIA PORIFERA PORIFERA PROTISTS 16 PROTISTS 17 Page ‹#› One hypothesis for evolution of One hypothesis for evolution of major animal phyla major animal phyla NEMATODA PLATYHELMINTHES PLATYHELMINTHES CNIDARIA CNIDARIA PORIFERA PORIFERA PROTISTS 18 PROTISTS 19 One hypothesis for evolution of One hypothesis for evolution of major animal phyla major animal phyla PROTOSTOMES PROTOSTOMES ARTHROPODA NEMATODA NEMATODA DEUTEROSTOMES ANNELIDA DEUTEROSTOMES MOLLUSCA PLATYHELMINTHES PLATYHELMINTHES CNIDARIA CNIDARIA PORIFERA PORIFERA PROTISTS 20 PROTISTA 21 One hypothesis for evolution of What key features differentiate animals major animal phyla from protists? PROTOSTOMES PROTOSTOMES ARTHROPODA ARTHROPODA NEMATODA NEMATODA ANNELIDA DEUTEROSTOMES ANNELIDA DEUTEROSTOMES MOLLUSCA MOLLUSCA PLATYHELMINTHES PLATYHELMINTHES CNIDARIA CNIDARIA PORIFERA ECHINODERMATA PORIFERA ECHINODERMATA CHORDATA CHORDATA PROTISTS 22 PROTISTS 23 Page ‹#› What key features differentiate animals Simple animals - the Porifera from protists? (Sponges) PROTOSTOMES ARTHROPODA NEMATODA ANNELIDA DEUTEROSTOMES MOLLUSCA PLATYHELMINTHES CNIDARIA PORIFERA ECHINODERMATA CHORDATA MULTICELLULARITY, ECM PROTISTA 24 25 Where do our sponges get their Simple animals - the Porifera (Sponges) name? Pore cells H2O Tube organization Several cell types in ECM - H2O like fruit in jello choanocytes Cells that move water and absorb food Fig. 32.4 26 from text “Choanocytes” 27 Simple animals - the Porifera Simple animals with cellular (Sponges) organization - the Porifera (sponges) Protist ancestors of The choanocytes animals? Choanoflagellates colonial Sponge protists with similar cell Regulate H20 movement with choanocyte types flagellum Since 1880s Collect food particles at flagellum similarity noted base, absorb directly into the cell Recently (2001): signalling gene in common choanoflagellate 28 29 Page ‹#› So, sponges have what kind of Party tricks digestion? with sponges… Intracellular digestion - digest food within individual cells What does this mean about the size of the food they can eat? Cells from a sponge can be completely disassociated, strained through a filter... And they will re-form into a sponge again in a few weeks What does this mean about the way 30 they are organized? 31 Simple animals with cellular One last thing about sponges… organization - the Porifera (sponges) If a tissue is a group of similar They’re cells organized into a functional asymmetrical unit, do sponges have tissues? -tubes grow into other tubes - can’t bisect them and Sponges have cellular make two equal organization halves 32 33 The Cnidaria The Cnidaria Two cell layers Tentacles around a mouth that closes Is it symmetrical? Cross section of a 34 sea anenome 35 Page ‹#› Evolution of symmetry Radial symmetry Asymmetrical Radial Bilateral A plane through the center in any symmetry symmetry direction will bisect the organism into equal halves 36 37 Advantages of bilateral Bilateral symmetry symmetry? A front and a back as well as a top and a bottom Allows concentration of sensory apparatus on one side (front) of one end (top!) Why is this a good thing for mobile animals? Only a single plane will bisect the organism into equal halves 38 39 The innovations of the Cnidaria The innovations of the Cnidaria Cells work together in Cnidarian dining layers: tissue organization What kind of If we disassociated the digestion? cells of a cnidarian and left them in a tank ? Cross section of a Cross section of a sea anenome 40 sea anenome 41 Page ‹#› The innovations of the Cnidaria The innovations of the Cnidaria Do cnidarians have Extracellular a gut? digestion Where do their waste products What does this mean go? about the size of Mouth but no anus food they can consume? What are the problems with this? Cross section of a Cross section of a sea anenome 42 sea anenome 43 The innovations of the Cnidaria Evolution of the coelom What’s a coelom? Review: Is it the same thing as a gut? Radial symmetry Where is the coelom on humans? Extracellular digestion Mouth but no anus - in Nematoda have both And… No coelom 44 45 Evolution of the body cavity - the We will distinguish between 3 types of coelom animals Acoelomate (‘a’-without) - e.g. In humans Sponges, Cnidaria, Flatworms divided In (Platyhelminthes) into two - earth- thoracic worms, coelom and in each abdominal seg- cavities ment 46 47 Page ‹#› We will distinguish between 3 types of We will distinguish between 3 types of animals animals Acoelomate (‘a’-without) - e.g. Pseudocoelomate - e.g. Nematoda Sponges, Cnidaria, Flatworms (Platyhelminthes) Ectoderm Ectoderm Mesoderm layer Mesoderm - solid Cavity Endoderm Endoderm Gut cavity Gut cavity 48 49 We will distinguish between 3 types of Which is acoelomate? Coelomate? animals Pseudocoelomate? Coelomate - e.g. all protostomes and deuterostomes Mesoderm surrounds cavity (coelom) and gut Ectoderm Mesoderm layers (two!) Cavity Endoderm Gut cavity 50 51 Why was evolution of a coelom important in animal evolution? What differentiates these groups? 3 reasons (not all relevant for all groups) PROTOSTOMES ARTHROPODA DEUTEROSTOMES 1) Coelom can function as a simple NEMATODA ANNELIDA circulatory system MOLLUSCA PLATYHELMINTHES 2) Fluid in a body cavity can help make CNIDARIA the body rigid - a hydrostatic skeleton PORIFERA ECHINODERMATA CHORDATA 3) Organs can function without being deformed by surrounding muscles Allows the development of a longer gut, can be coiled, etc. How long is the combined human small and large intestines? 52 PROTISTA 53 Page ‹#› Groups can be distinguished by In Protostomes (‘proto’-first, ‘stome’-mouth) early embryonic development - the blastopore gives rise to the mouth Blastopore Blastopore Blastula Gastrula 54 55 In Deuterostomes (‘deutero’- 2nd, ‘stome’- mouth) - the blastopore gives rise to the Mapping body plan characters on anus the tree PROTOSTOMES ARTHROPODA DEUTEROSTOMES NEMATODA ANNELIDA MOLLUSCA PLATYHELMINTHES Blastopore CNIDARIA PORIFERA ECHINODERMATA CHORDATA EXTRACELLULAR DIGESTION? 56 PROTISTAMULTICELLULARITY, ECM 57 Mapping body plan characters on the tree Mapping body plan characters on the tree PROTOSTOMES PROTOSTOMES ARTHROPODA DEUTEROSTOMES ARTHROPODA DEUTEROSTOMES NEMATODA NEMATODA ANNELIDA ANNELIDA MOLLUSCA MOLLUSCA PLATYHELMINTHES PLATYHELMINTHES CNIDARIA CNIDARIA PORIFERA ECHINODERMATA PORIFERA ECHINODERMATA CHORDATA CHORDATA RADIAL TISSUES? SYMMETRY? BILATERAL TISSUES EXTRACELLULAR DIGESTION EXTRACELLULAR DIGESTION SYMMETRY? PROTISTAMULTICELLULARITY 58 PROTISTAMULTICELLULARITY 59 Page ‹#› Mapping body plan characters on Mapping body plan characters on the tree the tree PROTOSTOMES PROTOSTOMES ARTHROPODA DEUTEROSTOMES ARTHROPODA DEUTEROSTOMES NEMATODA NEMATODA ANNELIDA ANNELIDA MOLLUSCA MOLLUSCA PLATYHELMINTHES PLATYHELMINTHES CNIDARIA CNIDARIA RADIAL SYMMETRY RADIAL SYMMETRY MOUTH PORIFERA ECHINODERMATA PORIFERA ECHINODERMATA CHORDATA CHORDATA AND ANUS MOUTH AND TRUE MOUTH AND ANUS ANUS? COELOM? BILATERAL SYMMETRY BILATERAL SYMMETRY TISSUES TISSUES EXTRACELLULAR DIGESTION EXTRACELLULAR DIGESTION PROTISTAMULTICELLULARITY 60 PROTISTAMULTICELLULARITY 61 Mapping body plan characters on the tree PROTOSTOMES ARTHROPODA DEUTEROSTOMES NEMATODA ANNELIDA MOLLUSCA PLATYHELMINTHES CNIDARIA RADIAL SYMMETRY MOUTH PORIFERA ECHINODERMATA CHORDATA AND ANUS TRUE COELOM MOUTH AND ANUS BILATERAL SYMMETRY TISSUES EXTRACELLULAR DIGESTION PROTISTAMULTICELLULARITY 62 Page ‹#›.