ANIMAL EVOLUTION & DIVERSITY

Chapter 26

Nonchordate Invertebrates

Phyla- Porifera (have pores)

Multicellular Heterotrophic No cell walls Few specialized cells Clade- Meazoa

Phyla- CnidariaInclude: Jellyfishes, sea fans, sea anemones, hydras, corals carnivoresRadial symmetryStinging tenticles

Sponges Cnidarians

Nonchordate Invertebrates

Phylum- Arthropoda (joint feet)

Includes: spiders; centipedes; insects; and crustaceans (crabs)

Segmented body Exoskeleton Cephalization Jointed appendages

Phylum- Nematoda Include: nematodes,

roundworms, unsegmented worms (pseudocoeloms)

Specialized tissues, organ systems

Arthropods Nematodes (roundworms)

Nonchordate Invertebrates

Phylum- Platyhelminthes Soft Unsegmented Flattened worms Have tissues and internal

organ systems Bilateral symmetry cephalization

Phylum- Annelida Includes: earthworms,

marine worms, parasites, bloodsucking leeches

Segmented True coelom

Flatworms Annelids

Nonchordate Invertebrates

Phylum- Mollusca Includes: snail, slugs,

clams, squids, octopus Soft-bodied Internal or external shell True coeloms Complex organs Produce larvae

Phylum- Echinodermata Includes: sea stars,

urchins, and san dollars Spiny skin Internal skeleton Water vascular system Five-part radial symmetry

Mollusks Echinoderms

26.2

Chordates

Reptiles Evolved from ancient amphibians First to evolve to dry conditions

Have dry, scaly skin Well-developed lungs Strong limbs Shelled eggs that do NOT develop in water Four groups of reptiles: lizards, snakes,

crocodilians, turtles and tortoises, and tuatara Related to dinosours

Amphibians Live in water as larva, and land as adults Vertebrates Require water for reproduction Have lungs (adults) Moist skin (mucus glands) No scales or claws

Bony Fish Have skeletons Two groups of bony fish : Ray-finned and Lobe-

FinnedRay-finned Lobe-finned

Internal skeletonPaired finsScalesGills

Example: eels, goldfish, and catfish

Fleshy fins

Include: lungfish and coelacants

Tetrapods are four-limbed vertebrates

Birds Considered reptiles that regulate their

internal body temperature. Have feathers Two legs Lightweight bones Front limbs are wings

Jawless fish No jaws or teeth Skeletons are made of cartilage Include: lampreys and hagfishes Lack vertebra Have notochord

Mammals Mammary glands (produce milk) Hair Breathe air Four-chambered heart Maintain homeostasis (regulation of body

temperature)

26.3

Primate Evolution

What is a Primate? A mammal that has relatively long fingers and

toes with nails instead of claw Arms can rotate around the shoulder joints Strong clavicle Binocular vision (combine images from both

eyes, providing 3D views ) Well-developed cerebrum (“thinking” part of the brain allows complex behaviors)

Hominie Evolution Homonoids (include orangutans, gorillas, chimpanzee,

and humans) Hominines (hominoids that led to humans)

Skull, neck, spinal column, hip bones, and leg bones of early hominine species changed shape in ways that enabled later species to walk upright (BIPEDAL)

Hand evolved an OPPOSABLE THUMB that can touch the tips of the fingers (enables grasping)

Evolved larger brains