The Animal Kingdom: The Deuterostomes. Deuterostomes. Phylum Echinodermata 4/23/2012. Chapter 31. (bilateral ciliated larvae)

Transcription

1 Porifera Porifera Cnidaria Cnidaria Ctenophora Ctenophora Platyhelminthes Platyhelminthes Nemerteans Nemerteans Nematoda Nematoda Rotifera Rotifera Tardigrada Tardigrada Onychophora Onychophora Arthropoda Arthropoda Annilda Annilda Mollusca Mollusca Echinodermata Echinodermata Hemichoradates Hemichoradates 4/23/2012 Parazoa Eumetazoa Radiata Bilateria Acoelomates Pseudocoelomates Protostomia Coelomates Deuterostomia The Animal Kingdom: The Deuterostomes Pseudocoelom Deuterostome development Chapter 31 Radial symmetry Choanoflagellate ancestor True coelom Protostome development Three tissue layers (mesoderm) Bilateral symmetry Tissues (ectoderm and endoderm) Multicellularity Fig. 29-7, p. 627 Deuterostomes Parazoa Eumetazoa Radiata Bilateria Acoelomates Pseudocoelomates Protostomia Coelomates Deuterostomia Shared derived characters radial, indeterminate cleavage blastopore becomes anus larva have a loop-shaped ciliated band used for locomotion Pseudocoelom Deuterostome development Radial symmetry True coelom Choanoflagellate ancestor Protostome development Three tissue layers (mesoderm) Bilateral symmetry Tissues (ectoderm and endoderm) Multicellularity Fig. 29-7, p. 627 Phylum Echinodermata ~7,000 (sea stars, sand dollars, urchins, sea cucumbers Marine animals with spiny skin water vascular system tube feet Endoskeleton Radial symmetry (pentaradial symmetry) (bilateral ciliated larvae) Larvae exhibit bilateral symmetry 1

2 Class Asteroidea Sea stars central disc with five or more arms use tube feet for locomotion Class: Asteroidea (sea stars) skin gills carnivorous (mollusks, annelids) metabolic wastes exits by diffusion water vascular system able to regenerate appendages Endoskeleton covered by thin epidermis Madreporite coelom - complete digestive system no brain - - nerve rings around mouth Stone canal sexes separate - external fertilization Poorly developed circulatory system Ampulla Sea Star Body Plan Fig. 31-1, p

3 Porifera Porifera Cnidaria Cnidaria Ctenophora Ctenophora Platyhelminthes Platyhelminthes Nemerteans Nemerteans Nematoda Nematoda Rotifera Rotifera Tardigrada Tardigrada Onychophora Onychophora Arthropoda Arthropoda Annilda Annilda Mollusca Mollusca Echinodermata Echinodermata Hemichoradates Hemichoradates Choradates 4/23/2012 Parazoa Eumetazoa Radiata Bilateria Acoelomates Pseudocoelomates Protostomia Coelomates Deuterostomia Phylum: Hemichordata Sedentary worm-like marine animals Pseudocoelom Deuterostome development Radial symmetry True coelom Choanoflagellate ancestor Protostome development Three tissue layers (mesoderm) Bilateral symmetry Tissues (ectoderm and endoderm) Multicellularity Fig. 29-7, p. 627 Parazoa Eumetazoa Radiata Bilateria Acoelomates Pseudocoelomates Protostomia Coelomates Deuterostomia Phylum Chordata: Characteristics Radial symmetry Pseudocoelom Deuterostome development True coelom At some time during life cycle have: flexible, supporting notochord dorsal, tubular nerve cord pharyngeal (gill) slits muscular postanal tail endostyle (or thyroid gland) Choanoflagellate ancestor Protostome development Three tissue layers (mesoderm) Bilateral symmetry Tissues (ectoderm and endoderm) Multicellularity Fig. 29-7, p. 627 Chordate Body Plan Phylum Chordata Subphylum Urochordata (Invertebrate) Subphylum Cephalochordata (Invertebrate) Subphylum Vertebrata (Vertebrate) 3

4 Chordate Evolution Subphylum Urochordata Tunicates Invertebrate marine animals with tunics suspension-feeders Larvae are free swimming Most adults are sessile Incurrent siphon Ganglion Oral tentacles Pharynx with slits Endostyle Tunic Intestine Testis Ovary Heart Excurrent siphon Atrium Esophagus Digestive gland Stomach Fig. 31-5b, p. 672 Tunicate 4

5 Echinodermata (sea stars, sea urchins) Hemichordata (acorn worms) Urochordata (tunicates) Cephalochordata (lancelets) Vertebrata 4/23/2012 Pharynx with slits Incurrent opening Atrium Larva Excurrent opening Adhesive papilla Nerve cord Notochord Heart Stomach 0.5 mm Fig. 31-5c, p. 672 Chordata Subphylum Cephalochordata Lancelets Invertebrate, small, segmented, fishlike animals Deuterostome ancestor Fig. 31-5a, p. 672 Chordate Evolution Vertebrate Evolution 5

6 Vertebrate Characteristics Vertebral column: skeletal axis of body Cranium: braincase Neural crest cells: determine development of many structures Pronounced cephalization Complex brain Muscles attached to endoskeleton for movement KEY CONCEPTS Shared derived characters of vertebrates include a vertebral column, cranium, neural crest cells, and an endoskeleton of cartilage or bone Vertebrate Evolution Jawless Fishes Ostracoderms (extinct) among earliest known vertebrates Agnathans (hagfishes) class Myxini Lampreys. class Cephalaspidomorphi no jaws or paired fins; cartilage, gills, notochord Jawless Fish: Hagfish Vertebrate Evolution 6

7 Lampreys Vertebrate Evolution Class Chondrichthyes (Cartilaginous Fishes) Includes sharks, rays, skates Cartilaginous fishes have jaws two pairs of fins placoid scales Shark Structure Early Jawed Fishes 7

8 More developments of Cartilaginous fishes: - development of sense organs electrorecptors in head lateral line organs (all fish) Internal fertilization Oviparous lay eggs Shark Reproduction Ovoviparous young enclosed by eggs incubated in mother s body Viviparous young develop in mother s uterus nutrients transferred from mother s blood Bony fishes Osteicthyes Vertebrate Evolution 24,000 spp. 8

9 Class Actinopterygii ray-finned fishes Bony Fishes Characteristics of Bony fishes skeleton of bone most oviparous swim bladder (not all) bony dermal scales Class Actinistia coelacanths Class Dipnoi lungfishes Modern bony fishes Ray-finned bony ancestor (lungs) Lung fishes (3 genera (lungs enamel) Lobe-finned (lungs) Lobe-finned fishes (1) (Coelocanth) Modern Bony Fishes Modern day boney fish Swim bladder Nerve cord Dorsal fins Kidney Ureter Caudal fin Brain Nostril Pharynx Gills Heart Gonad Liver Stomach Pelvic fin Intestine Cloaca Urinary bladder Anal fin Fig , p. 680 Lung fish branch: Sarcopterygii We used to think Gave rise to lungfishes (class Dipnoi) Lungfishes coelacanths (class Actinistia) 9

10 Sarcopterygii Vertebrate Evolution Lungfishes gave rise to tetrapods land vertebrates Tiktaalik - transitional between fishes and tetrapods Early Tetrapods Class: Amphibia Early amphibians mainly aquatic moved onto land to find food, escape predators had limbs strong enough to support body weight on land - salamanders, frogs, toads, caecilians metamorphosis aquatic larvae terrestrial adult!!!! lungs + skin for gas exchange chambered heart: systemic circulation pulmonary circulation most oviparous - Water!! 10

11 Amniote Evolution Have body covering that retards water loss Have physiological mechanisms that conserve water Amniotic membrane Protection Keeps from drying out Temperature regulation Amniotic Egg (from drying out temperature) Class Reptilia A paraphyletic group dinosaurs, turtles, lizards, snakes, alligators Biologists classify amniotes in two main groups: diapsids and synapsids Amniotes Diapsids turtles, ichthyosaurs, tuataras, squamates (snakes and lizards), crocodiles, pterosaurs, saurischian dinosaurs, birds Diapsids Many biologists consider birds as feathered dinosaurs classify birds and most reptiles as diapsids Synapsids gave rise to therapsids, which gave rise to mammals 11

12 Therapsid Amniote Evolution 4 Groups of Extant Reptiles 1. Turtles, terrapins, tortoises 2. Snakes Reptile Characteristics 3. Tuataras 4. Crocadiles, alligators, caimans Reproduction internal fertilization leathery protective shell around egg embryo develops protective membranes (including amnion) Reptile Characteristics Dry skin with horny scales Lungs with many chambers Three-chambered heart some separation of oxygen-rich and oxygen-poor blood Class: Aves (birds) around 9,000 species - derived from dinosaurs - adaptations to flight feathers streamlined bodies light bones (fenestrated) No teeth - efficient lungs and circulatory systems - 4 chambered heart 12

13 Modern Birds Archaeopteryx Reptile-like - reptile teeth - long tail - wings w/claws Bird-like -wings - feathers - furcula Birds Adaptations for powered flight feathers wings light, hollow bones containing air spaces Four-chambered heart Very efficient lungs Birds Excrete solid metabolic wastes (uric acid) Endotherms maintain constant body temperature Well-developed nervous system Excellent vision and hearing 13

14 Mammal Evolution Mammals Characterized by hair mammary glands differentiated teeth three middle-ear bones Have highly developed nervous system and muscular diaphragm Are endotherms Subclass: Holotheria (monotremes) **** Oviparous!!!! Subclass: Metatheria (Marsupials) - Marsupium -- Viviparous Marsupials (Subclass Metatheria) Include pouched mammals kangaroos, opossums Young are born in embryonic stage Complete development in mother s marsupium nourished with milk from mammary glands 14

15 Placental Mammals (Subclass Eutheria) Characterized by placenta for exchange between embryo and mother Subclass: Eutheria (Placental mammals) Viviparous - Placenta (organ of exchange between mother and embryo) No loss of eggs Maternal bond Resources MYA On seeing the marsupials in Australia for the 1st time and comparing them to placental mammals: An unbeliever might exclaim surely two distinct creators must have been at work C. Darwin 200 Mammalia mammals (4,600 species) 225 Aves birds (9,000 species) 290 Reptilia reptiles (6,500 species) 350 Amphibia amphibians (4,000 species) 400 Osteicthyes Bony fishes (24,000 species) 400 Chondricthyes Cartilagenous fishes (850 species) Agnatha Jawless fishes (60 species) 15