DIVERSITY, CLASSIFICATION & EVOLUTION PART I VERTEBRATE ZOOLOGY (VZ Lecture01 – Spring 2012 Althoff - reference PJH Chapters 1-2)

Protists Protozoans (animal-like) Algae (plant-like) LIVING EUKARYOTIC Water & Slime Molds (fungi-like) MICROBESVISIBLE TO NAKED EYE MULTICELLULAR Plantae Fungi UNICELLULAR (mostly )

LIVING EUKARYOTIC VISIBLE TO NAKED EYE MULTICELLULAR Plantae Animalia Fungi (vertebrates & tunicates & cephalocordates)

EUKARYA Kingdom: ANIMALIA Phylum: CHORDATA Class Order Family Genus Species Domain : Cephalochordata Urochodata Craniata (Vertebrata)

MAMMALIA AVES REPTILIA AMPHIBIA OSTEICHTHYES CHONDRICHTHYES AGNATHA Urochordata Cephalochordata no jaws vertebrae no vertebrae jaws lungs limbs amniotic egg 7 classes of Vertebrates + the “outgroups”

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

Common ancestor PRIMITIVE CHARACTERISTICS DERIVED (ADVANCED) CHARACTERISTICS Common ancestor 1 2 AB C D

Characteristics

Create a CLADOGRAM

postanal tail notochord 1 4 dorsal nerve cord 2 pharyngeal pouches 3

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.

Human embryo at beginning of week 5 EYE BRAIN LIMB BUD Pharyngeal pouches

Pharyngeal Pouches….what they became in you! Ist pair:auditory lobes 2 nd pair: tonsils 3 rd & 4 th pairs: thymus gland & parathyroid gland

Single genus: CEPHALOCHORDATA: Lancelets Branchiostoma(Amphioxus)

TUNICATES (Urochordata)

UROCHORDATA: Tunicates (_________) 4 PHARYNX NOTOCHORD REMNANT REDUCED NERVOUS SYSTEM

UROCHORDATA: Tunicates (_________) PHARYNX NOTOCHORD REMNANT REDUCED NERVOUS SYSTEM 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… Chapter 9, Fig 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?