DIVERSITY, CLASSIFICATION &

EVOLUTIONPART 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)

MICROBES VISIBLE 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:

CephalochordataUrochodata

Craniata(Vertebrata)

MAMMALIA

AVES

REPTILIA

AMPHIBIA

OSTEICHTHYES

CHONDRICHTHYES

AGNATHA

Urochordata

Cephalochordata

no jaws

vertebrae

novertebrae

jaws

lungs

limbs

amnioticegg

7 classesof

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 ancestorPRIMITIVE

CHARACTERISTICS

DERIVED (ADVANCED)CHARACTERISTICS

Common ancestor

1

2

A BCD

Characteristics

Create a CLADOGRAM

postanal tail

notochord1

4

dorsalnerve 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

LIMBBUD

Pharyngealpouches

Pharyngeal Pouches….what they became in you!

• Ist pair: auditory lobes

• 2nd pair: tonsils

• 3rd & 4th pairs: thymus gland & parathyroid gland

Single genus:

CEPHALOCHORDATA: Lancelets

Branchiostoma (Amphioxus)

TUNICATES (Urochordata)

UROCHORDATA: Tunicates (_________)

4

PHARYNX

NOTOCHORDREMNANT

REDUCEDNERVOUS SYSTEM

UROCHORDATA: Tunicates (_________)

PHARYNX

NOTOCHORDREMNANT

REDUCEDNERVOUS SYSTEM

POSTANALTAIL

CHORDATES: Two Types• NON-VERTEBRATE

Urochordates & CephalochordatesAll small, all marine Few fossils found….why?

• VERTEBRATE VertebrataAquatic &

Terrestrial Cranium (or skull) = “____________” Most have vertebrae… again ____________ designation “fits” better

VERTEBRATES: Two Groups• ________________

Hagfishes & LampreysSharks, Rays & RatfishesBony fishesSalamanders, Frogs, & Caecilians

• ________________TurtlesTuatara, Lizards, & SnakesAlligators & CrocodilesBirdsMammals

___________: 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. 9-12 PJH)

• In other words, nearly all non-amniotes are __________ and amniotes are ____________

Diversity ofVERTEBRATES

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?