BIO_ANIM_L02_Editable_Presentationss.ppt

Animal evolution and diversity

1. Animal Evolution and Diversity

2. Learning Objectives
Explain how animal clades are defined.
Describe what the cladogram of invertebrates illustrates.
Express what can be learned from the chordate
cladogram.

3. Differences Between Clades

4. Origins of the Invertebrates

5. Cladogram of Invertebrates
Radial symmetry
Radial
symmetry
as adults

6. Sponges
• Tiny openings, or pores, all
over their bodies
•The most ancient animals
• No true tissues or organs

7. Cnidarians
• Aquatic
• Soft-bodied
• Carnivorous
• Radially symmetrical
• Stinging tentacles

8. Arthropods
• Bodies divided into
segments
• Tough exoskeleton
• Cephalization
• Jointed appendages

9. Roundworms
• Unsegmented
• Pseudocoeloms
• Digestive tract with two
openings

• Some free living, some
parasitic
• Some terrestrial, some
aquatic

10. Flatworms
• Unsegmented
• No coelom
• True tissues and
organ systems
• Simplest animals with
three germ layers

11. Annelids
• Segmented bodies
• True coelom
• Some terrestrial, some
aquatic
• Some free living, some
parasitic

12. Mollusks
• Internal or external shell
• True coelom
• Complex organ
systems
• Trochophore: free-living
larval stage

13. Echinoderms
• Spiny skin
• Internal skeleton
• Water vascular system
• Five-part radial
symmetry (adults)
• Deuterostomes

14. Cladogram of Chordates

15. Nonvertebrate Chordates
Major characteristics:
• lack vertebrae
• lack notochord as adults
• lack tail as adults
• larvae have all chordate characteristics

16. Jawless Fishes
Major characteristics:
• no true teeth or jaws
• skeleton made of cartilage
• modern examples: lampreys,
hagfishes

17. Sharks and Their Relatives
Major adaptations:
• jaws
• paired pectoral and pelvic fins
• powerful tail fins

18. Bony Fishes
Major adaptation:
• skeletons made of true bone
Ray-finned
• paired fins, scales, and gills
• fins have bony rays connected
by skin
Lobe-finned
• fleshy fins supported by larger
bones

19. From Fins to Feet
Digits on
front feet
Sturdy
hind feet
Agile feet
Fins for
steering
Larger
front fins
Flexible
wrists
Tiktaalik
Panderichtys
Eusthenopteron
Acanthostega
Ichthyostega
Proterogyinus

20. Amphibians
Major adaptations:
• lungs
• stronger limbs to support bodies on land
Other characteristics:
• moist skin with
mucous glands
• lack scales
and claws

21. Reptiles
Major adaptations:
• dry, scaly skin
• well-developed lungs
• strong limbs
• shelled eggs

22. Reptile Evolution
Common ancestor

23. Birds
Major characteristics:
• feathers
• strong, lightweight bones
• two legs covered with scales
• front limbs modified into wings
• regulate internal body
temperature

24. Mammals
Major characteristics:
• hair
• breathe air
• four-chambered hearts
• regulate internal body
temperature
• mammary glands in
females