Animal Evolution The Chordates. Chapter 26 Part 2

Transcription

1 Animal Evolution The Chordates Chapter 26 Part 2

2 26.10 Birds The Feathered Ones Birds are the only animals with feathers Descendants of flying dinosaurs in which scales became modified as feathers Long feathers are adapted for flight Downy feathers provide insulation

3 Dinosaurs and Feathers

4 Fig a, p. 446

5 Fig b, p. 446

6 Fig c, p. 446

7 Fig d, p. 446

8 Bird Adaptations Bird characteristics Eggs No teeth Produce body heat (endotherms) Lightweight skeleton, strong muscles, and efficient circulation and respiration for flight Wings with flight feathers

9 A Bird Egg

10 yolk sac embryo amnion chorion allantois hardened shell albumin ( egg white ) Fig , p. 446

11 Animation: Amniote egg

12 Adaptations for Flight

13 Fig a, p. 447

14 Fig b, p. 447

15 Fig c, p. 447

16 skull radius ulna humerus pectoral girdle internal structure of bird limb bones pelvic girdle sternum (breastbone) two main flight muscles attached to keel of sternum Fig c, p. 447

17 Animation: Avian bone and muscle structure

18 26.11 The Rise of Mammals Mammals are animals that nourish young with milk and have hair or fur; four kinds of teeth allow them to eat many kinds of food

19 Fig a, p. 448

20 Fig b, p. 448

21 incisors molars premolars canines Fig b, p. 448

22 Mammalian Evolution Monotremes (egg-laying mammals) and marsupials (pouched mammals) evolved during the Jurassic Placental mammals (mammals with a placenta that exchanges materials between the mother and embryo inside the body) evolved later

23 Distribution of Mammalian Lineages Mammals underwent adaptive radiation after dinosaurs died out Continental movements influenced distribution Some mammals show morphological convergence

24 Distribution of Mammalian Lineages

25 southern land mass Pangea A About 150 million years ago, during the Jurassic, the first monotremes and marsupials evolved and migrated through the supercontinent Pangea. B Between 130 and 85 million years ago, during the Cretaceous, placental mammals arose and began to spread. Monotremes and marsupials that lived on the southern land mass evolved in isolation from placental mammals. C Starting about 65 million ago, mammals expanded in range and diversity. Marsupials and early placental mammals displaced monotremes in South America. D About 5 million years ago, in the Pliocene, advanced placental mammals invaded South America. They drove most marsupials and the early placental species to extinction. Fig , p. 448

26 Paleocene Mammals

27 The Largest Land Mammal Giraffe rhinoceros (Indricotherium) lived in Asia during the Oligocene

28 Convergent Evolution

29 Key Concepts The Amniotes Amniotes reptiles, birds, and mammals have waterproof skin and eggs, highly efficient kidneys, and other traits that adapt them to a life that is typically lived entirely on land Reptiles and birds belong to one amniote lineage, and mammals to another

30 26.12 Modern Mammalian Diversity Egg-laying monotremes lay leathery eggs Spiny anteaters, platypus Pouched marsupials develop in a pouch Kangaroos, koala, opossum, Tasmanian devil Placental mammals include most living mammals Rodents and bats are the most diverse groups

31 Monotremes: Platypus

32 Marsupials

33 Placental Mammals: The Placenta

34 placenta uterus embryo Fig a, p. 451

35 Placental Mammals

36 26.13 From Early Primates to Hominids Primates: Mammalian subgroup including humans, apes, monkeys, and prosimians Anthropoids: Humans, apes, and monkeys Hominids: Humans and apes

37 Primate Classification

38 Primates

39 Adaptations for Walking Monkey, gorilla, and human

40 Overview of Key Trends Five trends led to uniquely human traits Enhanced daytime vision (binocular vision) Upright (bipedal) walking Better grips (power grip and precision grip) Modified jaws and teeth (omnivorous diet) Brain, behavior, and culture (transmission of learned behavior between individuals and generations)

41 Adaptations for Walking Location of the foramen magnum in four-legged and upright walkers

42 a Hole at back of skull; the backbone is habitually parallel with ground or a plant stem b Hole close to center of base of skull; the backbone is habitually perpendicular to ground Fig , p. 453

43 Better Grips Power grip (prehensile movement) and precision grip (opposable movement)

44 Origins and Early Divergences 65 mya: First primates (shrewlike) 36 mya: Tree dwelling anthropoids mya: First hominoids (early apes) 6 mya: Hominids

45 Early Primates

46 Fig a, p. 453

47 Fig (b-d), p. 453

48 26.14 Emergence of Early Humans 6-8 mya: Early hominids from Africa

49 a b c d e Sahelanthropus tchadensis 6 million years ago Australopithecus africanus million years ago Paranthropus boisei million years ago Homo habilis million years ago Homo erectus 1.9 million to 53,000 years ago Fig , p. 454

50 Australopiths The first bipedal hominids (Australopithacus) were probably human ancestors

51 Early Humans Humans are members of the genus Homo Homo habilis emerged during the late Miocene

52 Early Humans In Africa 1.8 mya, Homo erectus had a larger brain, used simple stone tools and built fires

53 Key Concepts Early Humans and Their Ancestors Changes in climate and available resources were selective forces that shaped the anatomy and behavior of early humans and their primate ancestors Behavioral and cultural flexibility helped humans disperse from Africa throughout the world

54 26.15 Emergence of Modern Humans H. erectus evolved in Africa and spread throughout the world H. neanderthalensis, H. floresiensis, and modern H. sapiens evolved from H. erectus

55 Two Models for the Origin of H. sapiens Multiregional model H. erectus in Africa and other regions evolved slowly into H. sapiens (based on fossil record) Replacement model H. sapiens arose from a single African population of H. erectus and drove all other populations to extinction (based on genetics)

56 Two Models for the Origin of H. sapiens

57 H. erectus H. sapiens Africa Asia Europe H. erectus H. sapiens Africa Asia Europe Time Fig , p. 456

58 Leaving Home Starting 120,000 years ago, long-term shifts in global climate drove humans from Africa into the Middle East, Africa, Australia and Eurasia 15,000 years ago, humans crossed a land bridge from Siberia to North America

59 Dispersal Routes of H. sapiens

60 Origins and Extinctions of Hominid Genera

61 Australopithecus anamensis Australopithecus africanus Homo rudolfensis Homo habilis Australopithecus afarensis Australopithecus garhi Homo erectus Homo floresiensis Homo sapiens Paranthropus aethiopicus Paranthropus robustus Paranthropus boisei Homo neanderthalensis present Time (millions of years ago) Fig , p. 458

62 Animation: Feather development

63 Animation: Fossils of australopiths

64 Animation: Genetic distance between human groups

65 Animation: Homo skulls

66 Animation: Mammalian dentition

67 Animation: Mammalian radiations

68 Animation: Primate evolutionary tree

69 Animation: Primate skeletons

70 Animation: Skulls of extinct primates

71 Animation: Structure of the placenta

72 ABC video: Frogs Galore

73 ABC video: Ancient Human Skull

74 ABC video: Dinosaur Discovery

75 ABC video: Cahuachi Excavation

76 Video: Interpreting and misinterpreting the past

77 Video: Bald eagles

78 Video: Elephant seals

79 Video: Frog swimming

80 Video: Gopher

81 Video: Grizzly bears

82 Video: Grizzly feeding

83 Video: Loggerhead turtle

84 Video: Bittern at nest

85 Video: Puffin in flight

86 Video: Salamander

87 Video: Sea lions

88 Video: Spotted owl in old-growth forest

89 Video: Sting rays

90 Video: Tadpoles

91 Video: Humpback whales

92 Video: Salamander gills