Animal Architecture PDF

1 OUTLINE Taxonomy and Phylogeny of Animals 1. Classification & Relationships 2. Modern Phylogenetic Systematics - Cladistics 3. Sources of Information 2 ANIMAL CLASSIFICATION AND...

1 OUTLINE Taxonomy and Phylogeny of Animals 1. Classification & Relationships 2. Modern Phylogenetic Systematics - Cladistics 3. Sources of Information 2 ANIMAL CLASSIFICATION AND RELATIONSHIPS: The Beginning Classification - a broad overview Carolus Linnaeus (1707 - 1778) Developed our current scheme of classification - based on morphology - hierarchical taxonomic framework - *binomial nomenclature (e.g. Anguilla japonica) King Kingdom species epithet Phillip Phylum Came Class Over Order 7 mandatory ranks For Family Over 30 taxonomic ranks Good Genus* for complex groups Soup Species* 3 Anguilla japonica Popillia japonica 4 ANIMAL CLASSIFICATION AND RELATIONSHIPS: Modernization PHYLOGENY [Gk. phylon, race; genesis, descent] history of development of species or other group Characters - organismal features used to construct a phylogeny [or evolutionary tree] Homology - character similarity resulting from common ancestry Homoplasy - non-homologous character similarity, misrepresents common ancestry Evolutionary convergence of fusiform shape an example of homoplasy 5 MODERN PHYLOGENETIC SYSTEMATICS CLADISTIC ANALYSIS How do we use character variation to reconstruct phylogeny? Cladistics - evaluation of information for tree building and classification Cladogram - phylogenetic diagram based on cladistic analysis Tiger Domestic cat Common ancestor (to cats) Clade group of organisms that includes most recent common ancestor and all members and descendents of that ancestor 6 MODERN PHYLOGENETIC SYSTEMATICS CLADISTIC ANALYSIS Polarity - ancestral/descendent relationships among different states of a character (e.g. presence or absence of vertebral column) Outgroup comparison - examines polarity of a character state Nested hierarchy (of clades within clades) Frogs, Lizards, Monkeys and Bears all have eggs. Monkey Egg is the character. OUTGROUP Bear Frog Lizard The state of the character or Polarity for egg is Hair whether the egg has an Amniotic egg amnion or not. Lizard, Monkey and Bear Synapomorphy: amniotic egg of have eggs with amnion Lizard, Monkey and Bear therefore form a clade. 7 MODERN PHYLOGENETIC SYSTEMATICS CLADISTIC ANALYSIS Sources of phylogenetic information Comparative morphology - shapes & sizes of organismal structures, including developmental origins Living and fossil records e.g. skull bones, limb bones, structure of integument (scales, hair, feathers) Comparative biochemistry - gene and protein sequencing e.g. mtDNA – fast change Living and some fossil rRNA – slow change material Comparative cytology - numbers, shapes & sizes of chromosomes and associated material Living material only 1 OUTLINE Animal Architecture 1. Levels of Organization 2. Organ Systems & Extracellular Components 3. Tissue Types 4. Body Plans 2 FIVE GRADES OF ORGANIZATION WITHIN ANIMAL & ANIMAL-LIKE GROUPS (A) Protoplasmic level of Organization (A) - All life functions within a single cell - Differentiated organelles that perform specific functions (B) (B) Cellular level of Organization - Aggregation of cells exhibiting functional differentiation (C) - Division of labor between cells (e.g. reproduction, nutrition..) - Cells NOT organized into tissues (C) Cell-tissue level of Organization - Aggregation of cells into tissues (definite patterns/layers) 3 FIVE GRADES OF ORGANIZATION WITHIN ANIMAL & ANIMAL-LIKE GROUPS (C) (D) Tissue-organ level of Organization (D) - Aggregation of tissues into organs - Organs made up of more than one kind of tissue - parenchyma & stroma (E) Organ-system level of Organization (E) - Organswork together as a system to perform a function - Systems associated with basic body functions 4 ORGAN SYSTEMS 11 ORGAN SYSTEMS OBSERVED WITHIN ANIMALS 1. Digestive 2. Circulatory 3. Respiratory 4. Immune 5. Skeletal 6. Endocrine 7. Excretory 8. Nervous 9. Integumentary 10. Reproductive 11. Muscular Which organs work together to constitute the digestive system? 1. Gastrointestinal (GI) tract 2. Accessory digestive organs oral cavity salivary glands pharynx liver oesophagus gallbladder stomach pancreas intestine 5 TISSUE TYPES Tissue – an organization of like cells; the fundamental structure of which animal organs are composed 1. Epithelial tissue - sheets of cells that cover an external or internal surface, different types exist 2. Connective tissue - diverse group of tissues, specialized to bind and support other tissues 3. Muscular tissue specialized for voluntary and involuntary movement of various organs. 4. Nervous tissue - specialized for reception and conduction of stimuli and impulses. 6 EPITHELIAL TISSUE 1. Simple squamous epithelia 2. Simple cuboidal epithelia - flattened cells (“carpet”) - short, boxlike cells - facilitates movement of - active secretory or gases and other molecules absorptive functions (blood capillaries, lungs) (kidney, salivary glands) 3. Simple columnar epithelia - tall elongated cells - often associated with highly absorptive surfaces (Intestinal tract) 7 EPITHELIAL TISSUE 4. Stratified squamous epithelia - layered to withstand mild mechanical abrasion - basal cells push upward (oral cavity, esophagus) 5. Transitional epithelia - stratified but specialized to Unstretched accommodate stretching. (urinary tract, bladder) Stretched 8 EXTRACELLULAR COMPONENTS NONCELLULAR COMPONENTS (Remove Cells from Fluids and Connective Tissues): 1. Body fluids: multicellular animals contain two fluid compartments - intracellular space – within cells - extracellular space – outside cells (i) blood plasma - fluid portion of blood outside cells (ii) interstitial fluid - occupies space surrounding cells 2. Extracellular structural elements - Supportive material - loose connective “tissue” - cartilage - bone - cuticle 9 BODY PLANS Flatworm Mollusc Fish Amphibian Reptile Annelid 10 BODY PLANS 1. SYMMETRY (i) Asymmetry - no body axis and no plane of symmetry Unicellular Eukaryotes (amoeba) Poriferans (sponges) 11 BODY PLANS 1. SYMMETRY (ii) Spherical symmetry - any plane passing through center divides body equally - rare, found only in unicellular eukaryotes - no differentiation along an axis Unicellular eukaryotes (radiolarians) 12 BODY PLANS 1. SYMMETRY (iii) Radial symmetry body axis - divided equally by more than two planes passing through the longitudinal axis - body has the general form of a cylinder - rare e.g. polyps, some sponges - most forms are modified (e.g. pentaradial) 13 BODY PLANS 1. SYMMETRY (iv) Bilateral symmetry - body parts oriented around a single anterior to posterior axis - division along the saggital plane results in two equal halves - associated with cephalization - animal usually moves head first such that the anterior of the animal confronts environment first 14 BODY PLANS Chordates BILATERAL Arthropods Hemichordates Annelids Brachiopods Echinoderms Mollusks Bryozoans Nematodes Nemerteans Gastrotrichs Rotifers Flatworms Cnidarians * Sponges Ancestral Metazoan RADIAL * Unicellular Eukaryotes SPHERICAL * Asymmetry 15 BODY PLANS 2. INTERNAL BODY ARCHITECTURE The coelom - body cavities within bilateral animals coelom - fluid filled cavity between outer body wall and gut - enables internal organs to grow larger & become more sophisticated - fluid cushions internal organs, preventing injury - act as a hydrostatic skeleton, providing support for soft-bodied animals 16 1. Acoelomate Ectoderm Endoderm - no true coelom (i.e. no body cavity) - region between ectoderm and gut occupied Flatworm - parenchyma (mesoderm) Mesoderm 2. Pseudocoelomate - possess a pseudocoel - “tube within a tube” arrangement - no peritoneum (i.e. no cellular Roundworm membrane derived from mesoderm) Pseudocoel Coelom 3. Coelomate - true coelom lined with peritoneum Earthworm 17 BODY PLANS 2. INTERNAL BODY ARCHITECTURE The coelom - body cavities within bilateral animals :ectoderm :endoderm :mesoderm :peritoneum parenchyma Keywords (mesoderm) 1. Acoelomate no coelom parenchyma pseudocoel 2. Pseudocoelomate pseudocoel no peritoneum coelom 3. Coelomate true coelom with peritoneum 18 BODY PLANS Chordates BILATERAL Arthropods Hemichordates Annelids Brachiopods Echinoderms Mollusks Bryozoans Nematodes Nemerteans Gastrotrichs Rotifers Flatworms Cnidarians Sponges Ancestral Metazoan Unicellular Eukaryotes 19 BODY PLANS Chordates COELOMATE Arthropods Hemichordates Annelids Brachiopods Echinoderms Mollusks Bryozoans Nematodes Nemerteans Gastrotrichs Rotifers ACOELOMATE Flatworms Cnidarians PSEUDOCOELOMATE Sponges Ancestral Metazoan Unicellular Eukaryotes