Transcript Animals
Evolution of the Tetrapods Evolution of the Tetrapods Vertebrates The Origin of Tetrapods The first vertebrates on land were amphibians in the Devonian (400 mya) Arose from the rhipidistian (a family of lobed finned fish) (based on morhpology) or a lungfish (DNA) Origin of Tetrapods Origin of Tetrapods Classification Phylum: Chordata Subphylum: Vertebrata Superclass: Gnathostomata Class: Amphibia – Order: Urodela (Salamanders) – Order: Anurans (Frogs and Toads) – Order: Apodans (Caecilians) Class: Amphibia Two lives – refers to metamorphosis of many frogs Skin smooth and moist (cutaneous respiration) 3 _____ chambered heart with a double circulation system Mesolecithal eggs with jelly-like membrane Order: Urodela 400 species Salamanders Retain their tail as adults Limbs are at right angles to the body Carnivorous Most have internal fertilization using a Spermatophore _____________ Axolotl paedomorphosis Order: Anurans 3500 species Frogs and Toads Lose their tail as adults Hind limbs are adapted for jumping Tongue connected to front of mouth Secrete mucus External __________ Fertilization Order: Apodans 150 species Caecilians Legless and blind Mostly Tropical Internal __________ Fertilization Usually give birth to live young. Gas Exchange Conditions for Respiratory Surfaces Large Thin Moist surface area Aquatic vs. Terrestrial 1 Less than ____% oxygen Oxygen amounts decrease as the temperature increases Aquatic animals use large amounts of energy to obtain 20 oxygen (____%) 21 About _____% oxygen Developed invaginations to increase surface area and decrease evaporation Terrestrial animals may use only 1% 2% of its energy to obtain oxygen Respiratory Surfaces Cutaneous Respiration Gills Tracheal Lungs Systems Cutaneous Respiration Direct diffusion of gases between the organism and the environment Found in Porifera, Cnidarians, Platyhelminthes, nematodes, Annelids, and some Amphibians Supplements other organisms (amphibians) Gills Found in echinoderms, mollusks, annelids, arthropods, some vertebrates Countercurrent Gas Exchange Countercurrent Gas Exchange Maintains gradient over the whole length of the capillaries 80 Extracts ____% of the oxygen from the water Tracheal Systems Found in arthropods Tracheae – open tubes Spiracles – openings Tracheoles – contact with cells Muscle – increase amount of Carbon Dioxide removed Tracheal Systems Diffusion Lungs Found in invertebrates Gas moved primarily by diffusion – may be increased by body movement Modifications – snails - cavity with gill modified into lung – scorpions and spiders - invaginations of the abdomen Ventilation Lungs Found in amphibians, reptiles, mammals and birds Pharynx Larynx Trachea Bronchi Bronchioles Alveoli Alveoli Ventilating The Lungs _______ Positive Pressure Breathing – pushes air down trachea – seen in frogs and other amphibians Negative Pressure ________ Breathing – suction created by diaphragm – seen in mammals Negative Pressure Breathing Amniotic Egg Evolution of the _________ Allows animals to complete their entire life cycle on land Has shell that retains water (or is lost when kept inside mammals) Specialized extraembryonic membranes (not part of the animal) The Amniotic Egg Evolution of the Amniotic Egg Amnion - Protects from dehydration and mechanical shock Yolk Sac - Nutrient storage Albumin (egg white) - Nutrient storage Allantois - stores waste, gas exchange Chorion - gas exchange Amniotes Amniotes How Reptiles differ from Amphibians Tough, dry skin Amniotic egg Crushing or gripping jaws Copulatory organs More efficient circulatory system with a higher blood pressure More developed lungs (thoracic breathing) Better water conservation Better body support and limbs Better nervous system Classification Phylum: Chordata Subphylum: Vertebrata Superclass: Gnathostomata Class: Reptilia (not real) – Class: Testudines (Turtles and Tortoises) – Class: Spenodontia (Tuataras) – Class: Squamata (Lizards and Snakes) – Class: Crocodilia (Crocodiles and Alligators) Reptile Radiation Synapsids (therapsids) led to mammals Sauropsids Anapsid – _________ (turtles) Diapsid – _________ (all others) Class: Testudines (Chelonia) Protective Shell – Carapace (top) – Plastron (bottom) Land and Sea Evolved on land and returned to water (lay eggs on land) Largest, Leatherback Sea Turtle (2,000 lbs!) Class: Testudines (Chelonia) teeth No _____ Most move legs to breathe TDS (low:male high:female) Class: Sphenodontia Tuataras ___________ – Two living species (New Zealand) – Not a True Lizard (no external ears, different teeth) – Very Primitive (similar to mesozoic reptiles – Well developed eye below skin? Class: Squamata Lizards – geckos, iguanas, skinks, chameleons terrestrial, burrowing, aquatic, arboreal moveable eyelids (in most) Paired copulatory organs Class: Squamata Tongue usually not bifurcated Lower jaw loosely connected to skull TSD (female to male) Parthenogenesis ______________ Class: Squamata Class: Squamata Class: Squamata Class: Squamata Gila Monster – • One of two poisonous lizards • Protein in saliva studied to treat diabetes. Class: Squamata Snakes Lack limbs Lack moveable eyelids Class: Squamata Bifurcated tongue Jacobson’s organ _________ Pit Vipers (Loreal Pits) Class: Squamata Venom – Viperidae (Folding Fangs) Rattlesnakes – Elapidae (Fixed Front Fangs) Cobras, Sea Snakes, Coral Snakes – neurotoxic – hemotoxic Class: Squamata Class: Squamata Class: Squamata Feeding Adaptations Teeth curved and pointed inward Quadrate Hinged __________ bone Bones of jaw are attached by muscles and ligaments Moveable palate Elastic skin No sternum Largest living reptiles Most closely related to dinosaurs Complete secondary palate ________ Four chambered heart (?) Nest temperature (female/male) Class: Crocodilia Dinosaurs and Pterosaurs Dinosaurs – – – – Ornithischian Saurischian Pterosaurs flying reptiles Animal Structure and Function (4th exam) Animal Nutrition Nutritional Requirements Undernourished – not enough calories Overnourished – too many calories Malnourished ____________ – missing one or more essential nutrients Essential Nutrients Essential Amino Acids Essential Fatty Acids Essential Vitamins Essential Minerals Essential Amino Acids Found in proteins – 20 different types 8 essential in adult humans (9 infants) all in animal proteins vegetarians need to eat grains and beans Histidine __________ – Essential in infants Essential Fatty Acids Unsaturated fatty acids – used to make phospholipids for membranes Essential Vitamins Fat Soluble – stored in fat D, A, K, E – ___________ Water Soluble – excreted in urine – B complex and C Essential Minerals Inorganic nutrients – Calcium & Phosphorous bones – Iron anemia – Iodine thyroid hormones – Sodium, Chlorine, & Potassium nerve function, water regulation Food Types Heterotrophic – – – – Herbivores Carnivores Omnivores Insectivores Feeding Adaptations Suspension Feeders Feeding Adaptations Substrate Feeders Feeding Adaptations Fluid Feeders Feeding Adaptations Bulk Feeders Intracellular Digestion Inside cells All animals Exclusive in: – Protista – Porifera Extracellular Digestion Outside cells All animals above the sponges Two Types Gastrovascular Cavity – _________________ Alimentary Canal – _________________ Gastrovascular Cavity One opening Found in Cnidaria and Platyhelminthes Alimentary Canal Two openings Allows for specialization – – – – – – – – Mouth Pharynx Esophagus Crop Gizzard Stomach Intestine Anus Mammalian Digestion Accessory Glands – salivary glands – pancreas – liver (emulsification) – gallbladder Peristalsis Sphincters “Food” – bolus – acid chyme – feces Macromolecule Digestion Mouth Carbo Protein Nucleic Fat Acids Initial Stomach Initial Intestine Main Main Initial Main Initial Main Dentition and Diet Nonmammal vertebrates Carnivores – canines (grasping/puncturing ) – incisors (tearing) – molars and premolars (crushing grinding) Herbivores Omnivores and Digestive Tracts Carnivores Herbivores shorter – ________ digestive system – small cecum Longer – ________ digestive system – large cecum