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VERTEBRATE ZOOLOGY (VZ Lecture01 – Spring 2012 Althoff - reference PJH Chapters 1-2). DIVERSITY, CLASSIFICATION & EVOLUTION PART I. Protists. Algae (plant-like). Plantae. Protozoans (animal-like). Water & Slime Molds (fungi-like). Fungi. UNICELLULAR ( mostly ). MULTICELLULAR.
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VERTEBRATE ZOOLOGY (VZ Lecture01 – Spring 2012 Althoff - reference PJH Chapters 1-2) DIVERSITY, CLASSIFICATION & EVOLUTIONPART I
Protists Algae (plant-like) Plantae Protozoans (animal-like) Water & Slime Molds (fungi-like) Fungi UNICELLULAR (mostly) MULTICELLULAR LIVING EUKARYOTIC MICROBES VISIBLE TO NAKED EYE
(vertebrates & tunicates & cephalocordates) Plantae Animalia Fungi MULTICELLULAR LIVING EUKARYOTIC VISIBLE TO NAKED EYE
Cephalochordata Urochodata Craniata (Vertebrata) Domain: EUKARYA Kingdom: ANIMALIA Phylum: CHORDATA Class Order Family Genus Species
7 classes of Vertebrates + the “outgroups” MAMMALIA amniotic egg AVES limbs REPTILIA lungs AMPHIBIA jaws OSTEICHTHYES vertebrae CHONDRICHTHYES AGNATHA no jaws Urochordata Cephalochordata no vertebrae
Cladistic Systematics • Make __________________ • “clad” is Greek (klados) for branch, stem “gramma” Greek for picture • Traces evolutionary history • Base of tree: primitive traits/characteristics Top of tree: derived or ____________ traits/characteristics
2 DERIVED (ADVANCED) CHARACTERISTICS D Common ancestor C A B Common ancestor PRIMITIVE CHARACTERISTICS 1
postanal tail 4 pharyngeal pouches dorsal nerve cord notochord 1 3 2
What is a CHORDATE? • NOTOCORD –dorsally-located, supporting rod. Found just above the nerve cord. Present in all represents ___ _________________________________ ______. In most vertebrates it is replaced by vertebral column • NERVE CORD –dorsal, tubular. Anterior portion becomes the brain (in most). Spinal cord in vertebrates
What is a CHORDATE? • PHARYNGEAL POUCHES —usually only “seen” during embryonic development among vertebrates (including humans). In nonvertebrate chordates, fishes, and amphibian larvae they become functioning gills • POSTANAL TAIL –simply a tail that is present, at least in the _______________ if not the adult stage, too. It extends beyond the anus.
Pharyngeal pouches Human embryo at beginning of week 5 EYE BRAIN LIMB BUD
Pharyngeal Pouches….what they became in you! • Ist pair: auditory lobes • 2nd pair: tonsils • 3rd & 4th pairs: thymus gland & parathyroid gland
CEPHALOCHORDATA: Lancelets Single genus: Branchiostoma (Amphioxus)
UROCHORDATA: Tunicates (_________) PHARYNX NOTOCHORD REMNANT REDUCED NERVOUS SYSTEM 4
UROCHORDATA: Tunicates (_________) REDUCED NERVOUS SYSTEM NOTOCHORD REMNANT PHARYNX POSTANAL TAIL
CHORDATES: Two Types • NON-VERTEBRATE Urochordates & Cephalochordates All small, all marine Few fossils found….why? • VERTEBRATE Vertebrata Aquatic & Terrestrial Cranium (or skull) = “____________” Most have vertebrae… again ____________ designation “fits” better
VERTEBRATES: Two Groups • ________________ Hagfishes & Lampreys Sharks, Rays & Ratfishes Bony fishes Salamanders, Frogs, & Caecilians • ________________ Turtles Tuatara, Lizards, & Snakes Alligators & Crocodiles Birds Mammals
___________: Amnion Membrane • During embryonic development, relatively “new” advancement is the presence of 3 membranes formed by the tissues that come from the embryo itself. • “New” membrane layer is amnion….basically a key to successful reproduction on land (will discuss this “development” in more detail later this semester… Chapter9, Fig. 9-12 PJH) • In other words, nearly all non-amniotes are __________ and amniotes are ____________
Diversity of VERTEBRATES Fig. 1-1 p4 PJH
Major Classes – Diversity Today • Fishes ~28,048 • Amphibians ~ 5,465 • Reptiles ~ 8,073 • Birds ~ 9,000 • Mammals ~ 4,800 Patterns/trends?