1. Chordates

2. Characteristics common to ALL chordates Dorsal nerve cord Dorsal nerve cord Pharyngeal slits Pharyngeal slits Notochord Notochord Tail Tail

3. Dorsal nerve cord

4. Pharyngeal Slits The wall of the pharynx is perforated by up to 200 vertical slits, which are separated by stiffening rods. The wall of the pharynx is perforated by up to 200 vertical slits, which are separated by stiffening rods.pharynxslitspharynxslits

5. Jawless to Jaw

6. Used to collect food in an aquatic environment

7. Notochord a flexible, rod-shaped body found in embryos of all chordates a flexible, rod-shaped body found in embryos of all chordates embryoschordates embryoschordates

8. In lower vertebrates, it persists throughout life as the main axial support of the body, while in higher vertebrates it is replaced by the vertebral column. In lower vertebrates, it persists throughout life as the main axial support of the body, while in higher vertebrates it is replaced by the vertebral column.vertebratesaxial supportvertebral columnvertebratesaxial supportvertebral column

9. Tail

10. Some animals lose tail during development

12. Nonvertebrate chordates and Vertebrates Nonvertebrate chordates have a notochord (analogous to spinal chord) but lack a bony covering- the vertebrae Nonvertebrate chordates have a notochord (analogous to spinal chord) but lack a bony covering- the vertebrae Vertebrates have a spinal chord protected by bones Vertebrates have a spinal chord protected by bones

13. 13 Principle Chordate Features

14. 14 The Nonvertebrate Chordates Tunicates (sea squirts) Tunicates (sea squirts) –exhibit neither a major body cavity nor visible segmentation  tadpole larva clearly exhibits all basic characteristics of a chordate  adults exist as sessile filter-feeders

15. 15 Tunicates

16. 16 The Nonvertebrate Chordates Lancelets Lancelets –scaleless, fishlike marine chordates  notochord runs entire length of dorsal nerve cord  feed on microscopic plankton using cilia-generated current

17. 17

18. 18 Characteristics of Vertebrates Vertebral column Vertebral column Endoskeleton Endoskeleton Distinct, well-differentiated head with cranium Distinct, well-differentiated head with cranium Closed circulatory system with chambered heart Closed circulatory system with chambered heart RBC’s with hemoglobin RBC’s with hemoglobin

19. 19 Overview of the Evolution of Vertebrates Main CLASSES Main CLASSES –Fishes – cartilaginous and bony –Amphibia - amphibians –Reptilia - reptiles –Aves - birds –Mammalia - mammals

20. 20 Fishes Over half of all vertebrates are fishes. Over half of all vertebrates are fishes. Characteristics (generally) Characteristics (generally) –jaws and paired appendages (except lampreys and hagfish) –scales –fins –gills –single-loop blood circulation –Heart with 2 chambers (1 atrium, 1 ventricle) –Lateral line system

21. 21 History of the Fishes Rise of active swimmers Rise of active swimmers –Sharks and bony fishes replaced primitive fishes due to a superior swimming design.  caudal (tail) fin  dorsal (stabilizing) fins  pectoral (shoulder - elevator) fins  pelvic (hip- elevator) fins

22. 22 Hagfish

23. 23

24. 24 Lamprey

25. 25 History of the Fishes Sharks become top predators Sharks become top predators –Jaws with multiple rows of teeth –Paired pectoral and pelvic fins –Buoyancy from storing oil –extremely advanced reproduction  shark eggs fertilized internally  Most give birth to live young

26. 26 Hammerhead Shark

27. 27 Elephant Fish

28. 28 Whale Shark

29. 29 Tooth from Megalodon (left), and Great White

30. 30 History of the Fishes Bony fishes dominate the water Bony fishes dominate the water –Skeleton composed of bone –Swim bladder for bouyancy –Gills protected by operculum –highly mobile fins, thin scales, and completely symmetrical tails –Most have external fertilization and external development

31. 31 Angler Fish

32. 32 Deep Sea Angler Fish

33. 33 Flounder

34. 34

35. 35 Electric Eel

36. 36 Sea horse and Sea dragon

37. 37 Another Sea dragon

38. 38 Mola mola or Ocean sunfish

39. 39

40. 40 Coelacanth

41. 41 Coelacanth fossils

42. 42 Living Coelacanth

43. Shark Dissection Following is a series of video clips of dissection of various shark species. This will give you some idea of what you will encounter with our shark lab

44. 44 Lobe-Finned Fish and Primitive Amphibians

45. 45 Amphibians Live on both land and in water (“double life”) Live on both land and in water (“double life”) Characteristics Characteristics –legs –cutaneous respiration, lungs, gills –Heart with 3 chambers (double loop circulation)  Pulmonary  Systemic –External fertilization and development in nearly all

46. 46 History of the Amphibians Adaptations for the invasion of land Adaptations for the invasion of land –legs to support body’s weight –lung to extract oxygen from the air –redesigned heart to drive new respiratory system –reproduction in water to prevent egg desiccation –system to prevent body desiccation

47. 47 History of the Amphibians Amphibians today Amphibians today –Anura - amphibians without tails –most live in or near water, and return to water to reproduce  eggs fertilized externally and hatch into tadpoles –metamorphosis

48. 48 Poison dart frogs

49. 49 Proboscis frog

50. 50 African goliath frog

51. 51 Jabba the Frog

52. 52 Flying Frog

53. 53 Chinese fire-bellied toad (most venomous)

54. 54 History of the Amphibians –Urodela (Caudata) - salamanders  have elongated bodies, long tails, and sooth, moist skin –fertilization is usually external

55. 55 World’s largest salamander

56. 56 Spotted salamander

57. 57 Rodent surprise for lunch!

58. 58 History of the Amphibians –Apoda  caecilians - highly specialized group of tropical burrowing amphibians –legless, but have jaws and teeth –internal fertilization

59. 59 Caecilian

60. 60 Reptiles Characteristics Characteristics –amniotic egg  chorion - outermost membrane  amnion - encases embryo  yolk sac - surrounds yolk (food)  allantois - surrounds waste cavity –dry skin with scales –Internal fertilization; usually external development

61. 61 Baby komodo dragon

62. 62 embryo eggshell airspace allantois albumen amnion chorion Yolk sac

63. 63 Rise and Fall of Dominant Reptiles Dinosaurs: learning to run Dinosaurs: learning to run –body located directly over legs  increased speed and agility

64. 64 Apatosaurus

65. 65 Triceratops

66. 66 Diplodocus

67. 67 Stegosaurus

68. 68 Velociraptor

69. 69 Another reconstruction of Velociraptor

70. 70 Some pterosaurs were the size of small airplanes

71. 71

72. 72 Plesiosaurs were aquatic

73. 73 Japanese fisherman caught this creature in 1977

74. 74 Today’s Reptiles Of the 16 orders of reptiles that have existed, only 4 survive Of the 16 orders of reptiles that have existed, only 4 survive –turtles –lizards and snakes –tuataras –crocodiles

75. 75 Rise and Fall of Dominant Reptiles Other important characteristics Other important characteristics –internal fertilization –improved circulatory system –ectothermic - heat obtained from external sources –endothermic - generate own heat

76. 76 Gaping is a means of cooling the blood

77. 77 Living Reptiles Order Chelonia: turtles and tortoises Order Chelonia: turtles and tortoises –differ from other reptiles because their bodies are encased within a protective shell

78. 78 Some tortoises have lived to 150 years

79. 79 Green sea turtle

80. 80 Pacific leatherback sea turtle

81. 81 Rise and Fall of Dominant Reptiles Order Rhynchocephalia: tuatara Order Rhynchocephalia: tuatara –lizardlike animals about half a meter long –contain parietal eye –only found on island off New Zealand coast

82. 82

83. 83 Rise and Fall of Dominant Reptiles Order Squamata: lizards and snakes Order Squamata: lizards and snakes –three suborders  Sauria - lizards  Amphisbaenia - worm lizards  Serpentes - snakes –paired copulatory organ in males –lower jaw not joined directly to skull

84. 84 The chameleon is a lizard

85. 85 Jackson’s chameleon

86. 86

87. 87 Gecko

88. 88 Gila monster (venomous)

89. 89 Skinks are sometimes called worm lizards

90. 90 Blue-tongued skink

91. 91 World’s smallest skink

92. 92 Rainbow boa constrictor

93. 93

94. 94 Scarlet king snake

95. 95 Coral snake

96. 96 King or Coral?

97. 97 Copperhead

98. 98 Sidewinder rattlesnake

99. 99 Rattlesnake victim

100. 100 Rise and Fall of Dominant Reptiles Order Crocodilia: crocodiles and alligators Order Crocodilia: crocodiles and alligators –remained relatively unchanged  only two species of alligators –southern US and China –resemble birds more than other living reptiles (care for young and four-chambered heart)

101. 101 Nile crocodile

102. 102 Caimans live in South America

103. 103 Gharial

104. 104

105. 105 Birds Class Aves contains 28 orders containing 166 families and about 8,600 species. Class Aves contains 28 orders containing 166 families and about 8,600 species. –key characteristics  feathers –modified reptilian scales ?  flight skeleton –thin, hollow bones

106. 106 History of the Birds –Archaeopteryx (similar to modern Hoatzin) –Aves listed as separate class because of key evolutionary novelties of feathers, light bones, and super-efficient lungs

107. 107 History of the Birds Birds today Birds today –adaptations for flight energy demands  efficient respiration  efficient circulation  Endothermy

108. 108

109. 109 The “Great Nest” measures 9.5 ft. across, 20 ft. deep, and weighs an estimated 2 tons.

110. 110 Mammals Key mammalian characteristics Key mammalian characteristics –hair  heat loss  camouflage  sensory structures  defense weapon –mammary glands  about 50% of energy in milk comes from fat

111. A mother tiger, like other mammals, will not have to leave her young in order to find food for them

112. 112 Key Mammalian Characteristics endothermy endothermy –crucial adaptation that allowed activity at any time of the day to colonize severe environments placenta placenta –specialized organ allowing food, water, and oxygen to pass from mother to child teeth teeth –heterodont dentition (different teeth for different functions)

113. Neither of these animals is a fierce carnivore, despite the appearance of their teeth

114. 114 Key Mammalian Characteristics digestion of plants digestion of plants –cellulose major source of food for herbivores  mammals do not have necessary digestive enzymes to break apart cellulose –some have evolved four-chambered stomachs –some contain mutualistic bacteria in a cecum

115. Giraffes, like cows, possess a chambered stomach. All ruminants chew cuds

116. Although horses and zebras are herbivorous like giraffes, they do not have a rumen. Instead, they possess a cecum.

117. 117 Key Mammalian Characteristics hooves and horns hooves and horns –hooves specialized pads of keratin –horns composed of core of bone surrounded by keratin sheath flight flight –bats have wing of leathery membrane of skin stretched over the bones of four fingers  second largest order of mammals –echolocation

118. 118 History of the Mammals Orders of mammals Orders of mammals –monotremes: egg-laying mammals  lay shelled eggs –marsupials: pouched mammals  finish development in external pouch –placental mammals  placenta nourishes embryo throughout entire development  Gestation length related to size

120. echidna The echidna is also known as the spiny anteater

121. koala Koala young stay with the mother for an extended period of time, hitching a ride on mom’s back

122. They’re even cute when they’re asleep

123. Tasmanian devil Tasmanian Devil There really is a Tasmanian devil

124. kangaroo There are many species of kangaroo. In addition to the red (shown here), there is even a species that climbs trees

125. You didn’t believe me, did you?

126. The capybara is the world’s largest rodent.

127. sloth

128. Star nosed mole

129. Manatee? Manatees are very docile creatures

130. Notice the teeth on this orca

131. Beluga whale

132. The blue whale can measure over 90 ft. long and weigh over 200 tons

133. 133 Evolution Among Primates Primates Primates –two distinct features allowed them to succeed in arboreal environment:  grasping fingers and toes  binocular vision Prosimians (lemurs and tarsiers) Prosimians (lemurs and tarsiers) –Very smell oriented –Usually have long tails

134. The tamarin is a prosimian

135. The aye-aye is a most unusual prosimian

136. 136 Anthropoids Higher primates - includes apes, monkeys, and humans Higher primates - includes apes, monkeys, and humans –The term “Anthropoid” means “Like us” Direct descendents: Direct descendents: –New World monkeys (South America) –Old World monkeys (Africa)

137. mandrill The mandrill is an anthropoid monkey related to the baboon

138. New world monkeys like this spider monkey have prehensile or grasping tails. The Old World monkeys lack the ability to grasp with the tail

139. gorilla The “silverback” is a mature male gorilla who fears nothing

140. orang The orangutan is found only on Borneo and Sumatra

141. gibbon Gibbons are extremely athletic apes found in Southeast Asia. Like all apes, gibbons are tail-less

142. Chimpanzees have very complex social groups, interact often with one another, and are very devoted parents

143. Chimps have often been seen in the wild using tools. What do you suppose this guy is doing with the stick?

144. 144 Human evolution is very controversial Human evolution is very controversial Fossils are extremely rare and difficult to interpret Fossils are extremely rare and difficult to interpret Dating of fossils is also suspect Dating of fossils is also suspect H. sapiens is the only surviving hominid. H. sapiens is the only surviving hominid. –The best fossils are between 90,000 and 100,000 years old. –Cro-Magnons replaced Neanderthals about 40,000 years ago. –Humans of modern appearance eventually spread across Siberia to North America about 13,000 years ago.

145. 145