1. Figure 27.1 What adaptations make a chameleon a fearsome predator?

2. Time (millions of years age)
Sponges
Cnidarians
Echinoderms
Chordates
Brachiopods
Annelids
Molluscs
Figure 27.5 Appearance of selected animal groups
Arthropods
PROTEROZOIC
PALEOZOIC
Ediacaran
Cambrian
635
605
575
545
515
485 0
Time (millions of years age) 2

3. (Callyspongia plicifera)
Food particles
in mucus
Choanocyte
Collar
Flagellum
Choanocyte
Phagocytosis of
food particles
Amoebocyte
Pores
Spicules
Water
flow
Figure 27.3 Anatomy of a sponge
Amoebocytes
Azure vase sponge
(Callyspongia plicifera)

4. (a) Hydrozoa (b) Scyphozoa (c) Anthozoa
Figure 27.4 Major groups of cnidarians
(a) Hydrozoa
(b) Scyphozoa
(c) Anthozoa 4

5. (a) Valeria (800 mya): (b) Spiny acritarch roughly spherical, no
structural defenses,
soft-bodied
(b) Spiny acritarch
(575 mya): about five
times larger than
Valeria and covered in
hard spines
Figure 27.7 Indirect evidence of the appearance of bilaterians? 5

6. (b) Bilateral symmetry
(a) Radial symmetry
Figure 27.8 Body symmetry
(b) Bilateral symmetry 6

7. Body cavity Body covering (from ectoderm) Tissue layer
lining body cavity
and suspending
internal organs
(from mesoderm)
Digestive tract
(from endoderm)
Figure 27.9 Tissue layers in bilaterians 7

8. Porifera Ctenophora Metazoa ANCESTRAL PROTIST Cnidaria Eumetazoa
Hemichordata
770 million
years ago
Echinodermata
Deuterostomia
680 million
years ago
Chordata
Platyhelminthes
Rotifera
Bilateria
Ectoprocta
Lophotrochozoa
Figure A current hypothesis of animal phylogeny
Brachiopoda
670 million
years ago
Mollusca
Annelida
Nematoda
Ecdysozoa
Arthropoda 8

9. Figure 27.13 Myllokunmingia fengjiaoa, a 530-million-year-old chordate9

10. Dorsal, hollow nerve cord
Notochord
Dorsal, hollow nerve cord
Muscle
segments
Mouth
Figure Chordate characteristics
Anus
Post-anal tail
Pharyngeal slits or clefts 10

11. (a) Lancelet (b) Tunicate
Figure Present-day basal groups of chordates
(a) Lancelet
(b) Tunicate 11

12. Figure 27.16 Exploring vertebrate diversity
Common
ancestor of
vertebrates
Myxini
(hagfishes)
Petromyzontida
(lampreys)
Vertebrates
Vertebral
column
Chondrichthyes
(sharks, rays, chimaeras)
Actinopterygii
(ray-finned fishes)
Gnathostomes
Jaws,
mineralized
skeleton
Myxini
Actinistia
(coelacanths)
Dipnoi
Osteichthyans
Lungs
or lung derivatives
Lobe-fins
Dipnoi
(lungfishes)
Lobed
fins
Tetrapoda
(amphibians,
reptiles,
mammals)
Tetrapods
Limbs with digits
Petromyzontida
Figure Exploring vertebrate diversity
Chondrichthyes
Actinopterygii
Actinistia
Tetrapoda 12

13. 0.5 m
Figure Fossil of an early gnathostome 13

14. GREEN ALGA
MARINE CRUSTACEAN
AQUATIC LOBE-FIN
AQUATIC
ANCESTOR
Anchoring
structure
Derived (roots)
N/A
N/A
Support
structure
Derived (lignin/stems)
Ancestral
Ancestral (skeletal system)
Derived (limbs)
Internal
transport
Derived (vascular system)
Ancestral
Ancestral
CHARACTER
Muscle/
nerve cells
N/A
Ancestral
Ancestral
Protection
against
desiccation
Derived (cuticle)
Ancestral
Derived
(amniotic egg/scales)
Figure Descent with modification during the colonization of land
Gas exchange
Derived (stomata)
Derived (tracheal system)
Ancestral
TERRESTRIAL
ORGANISM
TERRESTRIAL
VERTEBRATES
LAND PLANTS
INSECTS 14

15. Cephalothorax Abdomen Thorax Antennae (sensory reception) Head
Swimming appen-
dages (one pair per
abdominal segment)
Figure External anatomy of an arthropod
Walking legs
Pincer
(defense)
Mouthparts
(feeding) 15

16. Lepidopterans Hymenopterans Hemipterans Figure 27.20 Insect diversity16

17. Figure 27.21 Ladybird beetle in flight17

18. Fish Characters Tetrapod Characters Scales Fins Gills and lungs Neck
Ribs
Fin skeleton
Flat skull
Eyes on top of skull
Shoulder bones
Neck
Ribs
Head
Scales
Eyes on top
of skull
Figure Discovery of a “fishapod”: Tiktaalik
Flat skull
Humerus
Ulna
“Wrist”
Elbow
Radius
Fin
Fin skeleton 18

19. Time (millions of years ago)
Lungfishes
Eusthenopteron
Panderichthys
Tiktaalik
Acanthostega
Tulerpeton
Limbs
with digits
Figure Steps in the origin of limbs with digits
Amphibians
Key to
limb bones
Ulna
Radius
Humerus
Amniotes
Silurian
PALEOZOIC
Devonian
Carboniferous
Permian
415
400
385
370
355
340
325
310
295
280
265
Time (millions of years ago) 19

20. Caecilians have no legs and are mainly burrowing Salamanders animals.
retain their tails
as adults.
Figure Amphibian diversity
Frogs and toads
lack tails as adults. 20

21. Extraembryonic membranes
Allantois
Chorion
Amnion
Yolk sac
Embryo
Amniotic
cavity with
amniotic fluid
Yolk
(nutrients)
Figure The amniotic egg
Shell
Albumen 21

22. Figure 27.26 Exploring reptilian diversity
†Plesiosaurs
Crocodilians
†Pterosaurs
Common
ancestor
of reptiles
†Ornithischian
dinosaurs
Turtles
†Saurischian
dinosaurs other
than birds
Common
ancestor
of dinosaurs
Birds
Turtles
Tuataras
Squamates
Squamates
Figure Exploring reptilian diversity
Crocodilians
Birds
Tuataras 22

23. Monotremes Marsupials Eutherians
Figure The major mammalian lineages 23

24. New World monkeys Old World monkeys Gibbons “Apes” Orangutans Gorillas
Figure The human evolutionary tree
Chimpanzees
and bonobos
Humans 24

25. (a) Ocean conditions before 600 mya
Murky, poorly-mixed
Low oxygen
Cyanobacteria
(a) Ocean conditions before 600 mya
Figure A sea change for Earth’s oceans
Clear, well-mixed
High oxygen
Eukaryotic algae
(b) Changes to ocean conditions by 530 mya 25

26. Figure 27.32 Results of reciprocal selection26

27. Age at maturity (years)
7.0
6.5
Age at maturity (years)
6.0
5.5
Figure Reproducing at a younger age
5.0
1960
1970
1980
1990
2000
Year 27

28. Workers on a mound of pearl mussels killed to make buttons (ca. 1919)
Other
invertebrates
An endangered
Pacific island
land snail,
Partula suturalis
Molluscs
Insects
Birds
Fishes
Amphibians
Figure The silent extinction
Mammals
Reptiles (excluding
birds)
Workers on a mound of pearl
mussels killed to make buttons
(ca. 1919)
Recorded extinctions of animal
species 28