Vertebrate Superchapter Sections 30 1 33 2 33

Vertebrate Superchapter Sections: 30 -1, 33 -2, 33 -3

Vertebrate Superchapter • Finally, a chapter we can relate to! • Will discuss non-vertebrate chordates briefly • Then will work our way though the rest of the phylum • Comparative anatomy

The Chordates (Vert-1 a) • Today’s Learning Objectives: – Know the terms in this chapter. – What are the 4 characteristics of chordates? – Describe the 6 groups of chordates. – Describe the 2 kinds of nonvertebrate chordates. – Describe the 3 groups of fish.

The Chordates • Chordates – the phylum of animals that includes vertebrates and some other animals

The Chordates • Chordates must have these four characteristics at some point in life 1. Dorsal hollow nerve cord 2. Notochord 3. Pharyngeal pouches 4. Post-anal tail

The Chordates • Dorsal nerve cord – Ex. spinal cord in humans • Notochord – Supporting rod just below the dorsal nerve cord – Not the same as a backbone – Humans have this only as embryos

The Chordates • Pharyngeal pouches – paired structures in the throat region – Ex. fish = gill slits & gills – Ex. humans = hyoid bone, ear bones • Post-anal tail – tail that extends beyond the anus

Human embryo – approx 40 days old

The Chordates • Chordate Cladogram

The Chordates • Six main groups of chordates 1. Nonvertebrate chordates 2. Fishes 3. Amphibians 4. Reptiles 5. Birds 6. Mammals

(By # of species) Nonvertebrate chordates (4%) Mammals (8%) Fishes (49%) Birds (17%) Reptiles (13%) Amphibians (9%)

JAWS Jaws helped vertebrates to become successful predators. VERTEBRAE Vertebrates have a segmented backbone. Amphibia Mammalia birds mammals Aves amphibians Osteichthyes bony fish Chondrichthyes cartilaginous fish lamprey Agnatha FOUR LIMBS Four limbs let animals move from the water to life on land. FEATHERS Feathers insulate birds from the cold and allow for flight. HAIR Hair helps mammals to maintain constant body temperatures by roviding insulation from the cold.

The Chordates • Nonvertebrate chordates - Invertebrates with notochords at some point in life cycle – Two kinds: tunicates & lancelets

Compare larvae to adult tunicate

Non-vertebrate chordates • Tunicates – AKA Sea Squirts – small marine organisms with free-living larvae, but look like sponges as adults • Lancelets – small fishlike creatures that have a wormlike lifestyle

Fish • Fish – aquatic vertebrates, usually with paired fins, gills, and scales – Key evolutionary advances: jaws and paired fins

Fish • Fins: – keep fish stable – redirect water around fish as it swims – help fish maneuver in water dorsal fin caudal fin anal fin pectoral fin pelvic fin

Fish • 3 groups of fish 1. Jawless fishes – have no jaws (lampreys and hagfish) 2. Cartilaginous fishes – have a skeleton made of cartilage (sharks and rays) 3. Bony fishes – have a skeleton made of bone (most fish)

Fish • Spotlight on: Hagfish! – Eel-like fish that eat dead & dying things – Secrete gigantic amounts of mucus that they use to lubricate their journey through dead bodies as they eat them – Video

Sharks https: //app. discoveryeducation. com/learn/vi deos/7 B 390584 -0 C 57 -454 E-95987257019 BFEE 6? has. Local. Host=false

The Chordates (Vert-1 b) • Today’s Learning Objectives: – Describe the 3 groups of amphibians. – Describe the 4 groups of reptiles. – Describe the 3 groups of mammals. – Know some of the key adaptations in chordate evolution.

Amphibians • Amphibians – vertebrates that live in water as larvae and on land as adults, have aquatic eggs – “double life” (amphi- plus bio-) – Key adaptations: Stronger bones and limbs, lungs

Amphibians • 3 groups of amphibians 1. Frogs and toads 2. Salamanders 3. Caecilians – legless, burrowing amphibians, look like worms, but have vertebrae

Amphibians • Frogs are the largest amphibian group. • There are over 3000 species of frogs. • Glands in the skin of frogs and toads contain poisons that help to protect them from predators.

Reptiles • Reptiles – vertebrates with dry, scaly skin, lungs, and terrestrial eggs – Allows the reptile to be fully terrestrial

Reptiles • Four groups of reptiles 1. Lizards and snakes 2. Crocodilians 3. Turtles and tortoises (turtles are partially aquatic, tortoises are not) 4. Tuatara - lizard-like reptile, lives only in New Zealand (https: //www. youtube. com/watch? v=v. Sh_fc 2 y 6 ds)

Birds • Birds – vertebrates with feathers and wings, endothermic – Key adaptations: feathers, efficient one-way lungs, lightweight bones, ability to slingshot – Approximately 30 different groups of birds!

Birds • Focus on: – Emperor Penguin • Aquatic bird • Up to 48” tall and 99 lbs! • Native to Antarctica • https: //www. youtube. com/watch? v=k 0 u 67 Wk_h. J 0

Mammals • Mammals – vertebrates with hair and mammary glands, endothermic – Generally terrestrial, breath air, four-chambered heart

Mammals • 3 groups of Mammals 1. Monotremes – egg-laying mammals (echidnas and platypuses) 2. Marsupials – give birth to live young at early stage of development, complete development in pouch (kangaroos, etc. ) 3. Placentals –young fed via placenta in womb, live birth (the rest of the mammals)

Mammals • Focus on: – Platypus (https: //www. youtube. com/watch? v=9 FTft 5 kxj s. E) • Duck-billed • Venemous • Egg-laying • Aquatic • Just plain freaky

Chordate Evolution • Key adaptations in chordate evolution – Vertebrae – Jaws & paired appendages – Lungs – Four limbs – Amniotic egg – has a shell, can develop on land – Endothermy

Vertebrae Jaws Paired appendages Lungs Amniotic egg Four limbs Endothermy

Controlling Body Temp (Vert-2) • Today’s learning objectives: – How do vertebrates control their body temperature? – Compare and contrast the advantages and disadvantages of endothermy and ectothermy.

Controlling Body Temp • Controlling body temperature – Important for homeostasis – More of an issue for land animals… why? – Because air fluctuates in temperature more than water (and more quickly than water)

Controlling Body Temp • Requires three features 1. A source of heat for the body 2. A way to conserve heat 3. A way to eliminate excess heat • How does a snake do this? • How does a dog? • How does a human?

Controlling Body Temp • Two groups – Ectotherm – animal whose body temperature is controlled primarily by the environment and response to the environment • Ex. fish, amphibians, reptiles – Endotherm – animal whose body temperature controlled internally • Ex. birds and mammals

Controlling Body Temp • Ectothermy – Advantages • Requires less food • More efficient in environments where the temperature doesn’t change much – Disadvantages • Move slowly in cold conditions or at night • Cannot live in very cold climates, especially if large

Controlling Body Temp • Endothermy – Advantages • Move around easily in cooler temperatures and at night • Can live in broader range of climates – Disadvantages • Requires a lot of food to maintain body temp • Inefficient if environment has constant temperatures

Controlling Body Temp • How did endothermy develop? – Current fossil evidence suggests it developed twice • Once with the reptiles the evolved into mammals • Once with the dinosaurs that evolved into birds

Chordate Form & Function (Vert-3) • Today’s Learning Objectives: – Be able to compare the different systems vertebrates have for: • Digestion • Respiration • Circulation • Legs • Development

Chordate Form & Function • This section describes various living strategies among the chordates. – Feeding – Respiration – Circulation – Response – Movement – Reproduction

Chordate Form & Function • Feeding – Teeth and jaws differ for feeding techniques – Digestive systems show differences depending on feeding habits • If a plant eater, you need long digestive tract, possibly with specialized pouches – Four stomachs in cows – Long cecum in rabbits – Crop and gizzard in birds

Digestive system comparison Shark Salamander Lizard Pigeon Cow

Chordate Form & Function • Respiration – Aquatic species use gills – Terrestrial species use lungs • Lungs get more complex for more active vertebrates • What kind of animal has the most advanced lungs? • Answer: Birds! They have an unusual system where air flows only in one direction through their lungs!

Chordate Form & Function • Circulation – Single-loop circulatory system – features twochambered heart and single path for blood • Heart → Gills → Body → Heart – Double-loop circulatory system – heart has 3, 3. 5, or four chambers and two paths for blood • Heart → Lungs → Heart • Heart → Body → Heart

Single-loop circulatory system Fishes Double-loop circulatory system Most reptiles Crocodilians, birds, and mammals

Chordate Form & Function • Hearts: – 2 chambers: fish – 3 chambers: amphibians – 3. 5 chambers: most reptiles – 4 chambers: birds, crocodiles, mammals – Basically we see the ventricle evolving a full separation to prevent oxygenated blood from mixing with oxygen-deprived blood

Chordate Form & Function • Response – Nervous systems become more complex, especially the brains, as move through groups of vertebrates

Chordate Form & Function • The brain – Cerebrum – part of brain that controls responses to environment, memory, & thought • Has more and more surface area and tends to be larger in birds and mammals – Cerebellum – part of brain that coordinates body movements and balance • Also gets more complex in birds and mammals

Chordate Form & Function • Movement – Backbone and muscles allow flexible movements – Legs – • Stick out in amphibians – carry weight poorly • Underneath body in birds and mammals – carries weight more efficiently • Act it out!

Chordate Form & Function • Reproduction – Three development patterns 1. Oviparous – embryo grows in egg outside the body (lay an egg) 2. Ovoviviparous – embryo grows in an egg inside the body, born live 3. Viviparous - embryo grows in body, gets nutrition from mother instead of egg, born live