Animals can be traced to a common ancestor a flagellated protist like a choanoflagellate (700 MYA)

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1 Animals can be traced to a common ancestor a flagellated protist like a choanoflagellate (700 MYA)

2 The ancestor of animals was probably a colonial, flagellated protist Cells in these protists Gradually became more specialized and layered Somatic cells Digestive cavity Reproductive cells 1 Colonial protist, an aggregate of identical cells 2 Hollow sphere of unspecialized cells (shown in cross section) 3 Beginning of cell specialization (cross section) 4 Infolding (cross section) 5 Gastrula-like proto-animal (cross section) Figure 18.2A

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4 Sponges Invertebrate: Porifera no distinct tissues or organs do have specialized cells no symmetry sessile (as adults) food taken into each cell by endocytosis

5 INVERTEBRATES Sponges have a relatively simple, porous body Sponges, phylum Porifera Are the simplest animals and have no true tissues

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7 Flagellated choanocytes Filter food from the water passing through the porous body Pores Amoebocyte Choanocyte Skeletal fiber Water flow Central cavity Flagella Choanocyte in contact with an amoebocyte

8 Invertebrate: Cnidaria Jellyfish, hydra, sea anemone, coral tissues, but no organs two cell layers radial symmetry predators tentacles surround gut opening extracellular digestion release enzymes into gut cavity

9 Stinging cells of mouth Cnidarians tentacles sensory cell stinging cell discharged nematocyst hydra trigger undischarged nematocyst stinging cell with nematocyst

10 Cnidarians are radial animals with tentacles and stinging cells Cnidarians, phylum Cnidaria Have true tissues and radial symmetry

11 Their two body forms are Polyps, such as hydra Medusae, the jellies Figure 18.6A C

12 They have a gastrovascular cavity And cnidocytes on tentacles that sting prey Tentacle Coiled thread Capsule (nematocyst) Trigger Discharge of thread Prey Cnidocyte

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14 Sea Nettle Portuguese man o war Sea wasp (box jelly)

15 Safe Comb Jellies

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17 Invertebrate: Platyhelminthes Flatworms tapeworm, planaria mostly parasitic bilaterally symmetrical allows high level of specialization within parts of the body now have a mouth at one end & an anus at the other! ectoderm mesoderm endoderm

18 Colorized SEM 80 Units with reproductive structures Hooks Sucker Scolex (anterior end)

19 Invertebrate: Nematoda Roundworms bilaterally symmetrical have both mouth & anus well-developed digestive system many are parasitic hookworm C. elegans

20 Ascaris

21 Invertebrate: Mollusca Mollusks clams, snails, squid bilaterally symmetrical (with exceptions) soft bodies, mostly protected by hard shells true coelem

22 Gastropods Gastropods are the largest group of molluscs And include the snails and slugs

23 Bivalves The bivalves have shells divided into two halves And include clams, oysters, mussels, and scallops

24 Cephalopods Cephalopods are adapted to be agile predators And include squids and octopuses

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27 Wiwaxia between mollusca and annelida

28 Open Versus Closed circulatory System Open circulatory system A heart pumps hemolymph through a hollow cavity to circulate O 2 and nutrients. Arthropods and some molluscs Closed Circulatory System a Heart pumps blood through closed blood vessels and lymph is kept separate. Chordates, cephalopods and annelids

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30 Invertebrate: Annelida Segmented worms earthworms, leeches segments are not specialized bilaterally symmetrical true coelem fan worm leech

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32 Invertebrate: Arthropoda Spiders, insects, crustaceans most successful animal phylum bilaterally symmetrical segmented allows jointed appendages exoskeleton chitin + protein

33 Arthropod groups arachnids 8 legs, 2 body parts spiders, ticks, scorpions crustaceans gills, 2 pairs antennae crab, lobster, barnacles, shrmp insects 6 legs, 3 body parts

34 Colorized SEM 900 Chelicerates Chelicerates include Horseshoe crabs Arachnids, such as spiders, scorpions, mites, and ticks A black widow spider (about 1 cm wide) A scorpion (about 8 cm long) A dust mite (about 420 µm long) Figure 18.11B, C

35 Millipedes and Centipedes Millipedes and centipedes Are identified by the number of jointed legs per body segment

36 Crustaceans The crustaceans Are nearly all aquatic Include crabs, shrimps, and barnacles

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38 Insects are the most diverse group of organisms Insects have a three-par t body consisting of Head, thorax, and abdomen Three sets of legs Wings (most, but not all insects)

39 Many insects undergo Incomplete or complete metamorphosis

40 A. Order Or thoptera The order orthoptera includes Grasshoppers, crickets, katydids, and locusts Head Thorax Abdomen Antenna Forewing Eye Figure 18.12A Mouthparts Hindwing

41 B. Order Odonata The order odonata includes Dragonflies and damselflies Figure 18.12B

42 C. Order Hemiptera The order hemiptera includes Bedbugs, plant bugs, stinkbugs, and water striders Figure 18.12C

43 D. Order Coleoptera The order coleoptera includes Beetles Figure 18.12D

44 E. Order Lepidoptera The order lepidoptera includes Moths and butter flies Figure 18.12E

45 F. Order Diptera The order Diptera includes Flies, fruit flies, houseflies, gnats, and mosquitoes Haltere Figure 18.12F

46 G. Order Hymenoptera The order hymenoptera includes Ants, bees, and wasps Figure 18.12G

47 Domain Eukarya Kingdom Animal Chapters The Animal Kingdom Clade Deuterostome Phylum Echinodermata Phylum - Chordata

48 Echinoderms have spiny skin, an endoskeleton, and a water vascular system for movement Echinoderms, phylum Echinodermata Includes organisms such as sea stars and sea urchins Are radially symmetrical as adults Tube foot Tube foot Spine Figure 18.13B, C

49 The water vascular system Has suction cup like tube feet used for respiration and locomotion Anus Spines Stomach Canals Tube feet Figure 18.13A

50 Starfish, Invertebrate: sea urchins, sea Echinodermata cucumber radially symmetrical spiny exoskeleton

51 Sponges Cnidarians Echinoderms Chordates Flatworms Molluscs Annelids Arthropods Nematodes The body plans of animals can be used to build phylogenetic trees One hypothesis of animal phylogeny Is based on morphological comparisons Deuterostomes Protostomes Radial symmetry Bilaterians Bilateral symmetry No true tissues Eumetazoans True tissues Ancestral colonial protist

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53 Deuterostome Clade Echinoderms (seastars and sea urchins) and Chordates (Us) are monophyletic. Protostomes make up two clades: Lophotrochozoa and Ecdysozoa. Lophotrochozoa are split into 2 groups: Trochopore larva (annelida and mollusca) and Lophophore bearing (flatworms, rotifers). Ecdysozoans shed an old exoskeletons (Nematodes and Arthropods).

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63 Our own phylum, Chordata, is distinguished by four features Chordates, phylum Chordata have A dorsal hollow ner ve cord A stiff notochord Pharyngeal slits A muscular post-anal tail

64 Vertebrate Evolution and Diversity Campbell s Chapter 34

65 Vertebrates belong to Phylum Chordata Chordata also includes: Urochordates - Tunicates Cephalochordates - Lancelets

66 Vertebrates fish, amphibians, reptiles, birds, mammals internal bony skeleton backbone encasing spinal column skull-encased brain Chordata hollow dorsal nerve cord becomes brain & spinal cord Oh, look your first baby picture! becomes gills or Eustachian tube becomes tail or tailbone pharyngeal pouches postanal tail becomes vertebrae notochord

67 All Chordates possess 1. Notochord - A rigid but flexible rod between the digestive tube and the dorsal nerve cord. 2. Dorsal hollow Nerve cord 3. Pharyngeal Slits 4. Muscular, Post-anal Tail

68 Chordate Characteristics

69 Subphylum Urochordates tunicates - seasquirts

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72 Cephaloch ordate - Lancelets

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74 Transitional Species 530 mya Haikouichthys A true vertebrate Myllokunmingia - early vertebrate

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76 Neural crest Forms from closing neural tube and will form parts of the bones and cartilage of the cranium.

77 Agnathans Jawless Ostracoderms million years ago

78 Hagfish slime-eels Has a cranium but no jaws, teeth or backbone. Still has Notochord

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80 Sea Lampreys Have a cranium and a cartilaginous partial wrapping around notochord. No jaws or teeth.

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84 Jaws evolved from Pharyngeal slits supports.

85 450 mya salmon, trout, sharks Characteristics body structure Vertebrates: Fish bony & cartilaginous skeleton jaws & paired appendages (fins) scales body function gills for gas exchange two-chambered heart; single loop blood circulation ectotherms reproduction external fertilization external development in aquatic egg gills body

86 Chondrichthyes includes Sharks and rays Jawed fish with Catilaginous skeletons

87 Have teeth and a lateral line Sharks have been around for more than 400 million years. Sharks existed about 200 million years before dinosaurs. There are more than 375 species of sharks living today.

88 Megalodon Fake

89 Whale Shark Largest extant fish feet

90 Osteichthyes Bony fish have Calcified endoskeleton Operculum gill covering 30,000 species Water comes in mouth through pharynx and out through the gills Swim bladder is used for buoyancy and came from lungs

91 Osteichthyes Bony fish Three Extant groups (classes) Actinopterygii ray finned fish Actinista Lobed finned fish Dipnoi - Lungfish

92 Actinopterygii ray finned fish Include commonly known fish like trout, perch and flounder. 1. Skin secrete mucus that reduces drag 2. Have keratin scales 3. Most reproduce externally 4. Two Chambered heart 5. Ectothermic

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94 Anatomy of typical Ray finned fish

95 Actinista Lobed finned fish Walk on bottom with muscular fins Coelacanth

96 Dipnoi - Lungfish All living lungfish live in the remnants of Gondwana; Australia, Africa and South America Have an amphibian-like lung

97 Tetrapod evolution from fish The split between fish and amphibians is very blurry. Lungfish and frogs breath the same way

98 Fossil record

99 From fish to Amphibians

100 Tiktaalik Fish with a neck

101 Femur Pelvis Tibia Humerus Ulna Shoulder Fibula Lobe-finned fish Radius Pelvis Femur Humerus Shoulder Fibula Tibia Early amphibian Ulna Radius

102 Acanthostega tetrapod FISH

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105 Ichthyostega

106 Class - Amphibians Amphi (two) bios (lives) spend part of the time in water and part on land 1. Breath through lungs and moist skin 2. Eggs are laid in water and larva (tadpoles) lose lateral line. 3. Ectothermic 4. Three Chambered heart

107 350 mya Vertebrates: Amphibian Amphi (two) bios (lives) spend part of the time in water and part on land frogs salamanders toads Characteristics body structure legs (tetrapods) moist skin body function lung lungs (positive pressure) & diffusion through skin for gas exchange three-chambered heart; veins from lungs back to heart ectotherms reproduction external fertilization external development in aquatic egg metamorphosis (tadpole to adult) glottis closed buccal cavity

108 Orders Order Urodela (tailed ones) Salamanders Order Anura No tails frogs and toads Order Apoda no legs legless

109 Urodela 500 species Lungless

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111 4,200 species Anurans

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114 Lungless frog

115 150 species Apodans

116 The Amniotes Class Mammals - you Class Testudines - turtles Class Sphenodontia - tuataras Class Squamata snakes and lizards Class Crocodilia- crocodiles and alligators Class Aves - birds

117 Amniotic Egg The egg has a shell that allows the animal to live on land exclusively (although many have returned to the water). Extraembryonic membranes Allantois disposal of waste Amnion protects embryo and prevents dehydration Chorion Exhange gases for the embryo Yolk Sac contains nutrients in yolk

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119 Skull features separated the Earliest Amniotes Synapsids - (One opening behind temple)lead to therapsids and mammals Anapsids - (No openings on the temple of the skull)lead to An extinct group of reptiles (and maybe turtles) Diapsids (two arches opening) Lead to the dinosaurs, modern reptile, archesaurs and birds

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123 Dimetrodon a mammal-like reptile

124 Titanophoneus a dominant Therapsid

125 Reptilian Heritage evident Terrestrial adaptations: Keratin scales protect from dessication (drying out) Must get all air from their lungs. Fertilization is internal Ectothermic absorb external heat but have behaviors that assist in temperature control. Three chambered heart The first radiation was based upon skull differences and happened about 250 MYA

126 250 mya Vertebrates: Reptiles Characteristics body structure dry skin, scales, armor body function lungs for gas exchange thoracic breathing; negative pressure three-chambered heart ectotherms reproduction internal fertilization external development in amniotic egg leathery shell dinosaurs, turtles lizards, snakes alligators, crocodile embryo amnion chorion allantois yolk sac

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128 The age of Reptiles The Mesozoic Era saw a wide diversification of reptiles and their cousins the dinosaurs. From 251 to 65 MYA When the dominant amphibians and therapsids went extinct at the end of the Permian (also ending the Paleozoic Era) Dinosaurs took over.

129 Testudines Turtles no openings in temples but other factors do not link them to the other anapsids.

130 Newly discovered fossil from China has shed light on how the turtle's shell evolved. The 220 million-year-old find, described in Nature journal, shows that the turtle's breast plate developed earlier than the rest of its shell. The breast plate of this fossil was an extension of its ribs, but only hardened skin covered its back.

131 Diapsids split into Lepidosauria Extinct oceanic reptiles Sphenodontia Mosasaurs Plesiosaurs Ichthyosaurs Squamata snakes and reptiles Archosauria- Crocodilians Pterosaurs Ornithischia Saurischians Aves

132 Leptidosaurians

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135 Class Sphenodontia - tuataras Last of a primitive reptile found only in New Zealand

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137 Archosauria Crocodilians Pterosaurs Ornithischia Saurischians Aves

138 Crocodilians Alligators and Crocodiles

139 pterosaurs

140 Ornithschians Herbivorous and extinct

141 Saurishians Herbivorous and carnivorous

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147 Archaeopteryx

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151 150 mya Vertebrates: Birds finches, hawk ostrich, turkey Characteristics body structure feathers & wings thin, hollow bone; flight skeleton body function very efficient lungs & air sacs four-chambered heart endotherms reproduction internal fertilization external development in amniotic egg trachea anterior air sacs lung posterior air sacs

152 Birds are a branch of the Saurischians

153 Birds 8,600 species Ratite birds are flightless. Form and function Four chambered heart Endothermic Hatched from eggs

154 220 mya / 65 mya mice, ferret elephants, bats whales, humans Vertebrates: Mammals Characteristics body structure hair specialized teeth body function lungs, diaphragm; negative pressure four-chambered heart endotherms reproduction internal fertilization internal development in uterus nourishment through placenta birth live young mammary glands make milk (specialized sweat glands) muscles contract diaphragm contracts

155 Split into three groups from the therapsids during the Mesozoic The Monotremes egg layers Marsupials pouches Eutherians Placental mammals

156 Marsupials versus Eutherians Probably split ~125 MYA Marsupials radiated in the southern continents Eutherians radiated in the northern land masses and spread south. A great deal of Convergent Evolution

157 Vertebrates: Mammals Sub-groups monotremes egg-laying mammals duckbilled platypus, echidna marsupials pouched mammals short-lived placenta koala, kangaroo, opossum placental true placenta shrews, bats, whales, humans

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173 Vertebrate quick check Which vertebrates lay eggs with shells? Which vertebrates are covered with scales? What adaptations do birds have for flying? What kind of symmetry do all vertebrates have? Which vertebrates are ectothermic and which are endothermic Why must amphibians live near water? What reproductive adaptations made mammals very successful? What characteristics distinguish the 3 sub-groups of mammals?

174 That s the buzz! Any Questions?