1Phylogenetic Tree of Reptiles

The The VertebratesVertebrates 2

MammalsMammals

Class MammaliaClass Mammalia

Thought to have evolved during the Thought to have evolved during the Mesozoic Era from therapsidsMesozoic Era from therapsids

Mammalian skull accommodates a larger Mammalian skull accommodates a larger brain relative to body sizebrain relative to body size

Chief characteristics and hair and milk-Chief characteristics and hair and milk-producing mammary glandsproducing mammary glands

Infant dependencyInfant dependency

Internal developmentInternal development

Differentiated teethDifferentiated teeth

The The VertebratesVertebrates 3

Mammals - MonotremesMammals - MonotremesMonotremes – (Greek. Monotremes – (Greek. monosmonos: one + : one + trematrema: hole): hole)

•Have a cloacaHave a cloaca

•Egg laying mammalsEgg laying mammals

•Hard-shelled amniotic eggsHard-shelled amniotic eggs

Platypus - young lick up milk off of the Platypus - young lick up milk off of the mothermother

Spiny anteater – young move from egg to Spiny anteater – young move from egg to a pouch a pouch

•All found in Australia or New GuineaAll found in Australia or New Guinea

The The VertebratesVertebrates 4

Mammals - MonotremesMammals - Monotremes

The The VertebratesVertebrates 5

Mammals - MarsupialsMammals - Marsupials

Marsupials – (Gk. Marsupials – (Gk. marsupiummarsupium: pouch): pouch)

•Females contain pouchFemales contain pouch

•Begin development inside females body Begin development inside females body and move to pouch; attach to nipplesand move to pouch; attach to nipples

•Frequently more babies are born than Frequently more babies are born than nipples availablenipples available

•Most abundant in Australia and New Most abundant in Australia and New Guinea, some in South and Central Guinea, some in South and Central America America

•1 in North America1 in North America

The The VertebratesVertebrates 6

Mammals - MarsupialsMammals - Marsupials

The The VertebratesVertebrates 7

Mammals - MarsupialsMammals - Marsupials

Tricky tree: DNA bits called retroposons reveal that marsupials share a South American ancestor but form distinct South American and Australian groups.

The The VertebratesVertebrates

Flying Squirrel vs Sugar Glider??Same thing?

Sugar gliders are marsupuals; flying squirrels are not?

Why do they look and behave so similarly?

The The VertebratesVertebrates 9

Mammals - PlacentalsMammals - PlacentalsPlacentals - Females have organ for Placentals - Females have organ for exchange of maternal and placental exchange of maternal and placental bloodblood

•Nutrients provided to growing offspringNutrients provided to growing offspring

•Active lifeActive life

•Acute sensesAcute senses

•Brain takes awhile to develop.Brain takes awhile to develop.

Why? Why?

How long for humans?How long for humans?

10Placental Mammals

The The VertebratesVertebrates 11

Major Orders of MammalsMajor Orders of Mammals

PerissodactylaPerissodactyla HorsesHorses

ArtiodactylaArtiodactyla DeerDeer

CarnivoraCarnivora CatsCats

PrimatesPrimates MonkeysMonkeys

CetaceaCetacea WhalesWhales

ChiropteraChiroptera

BatsBats

RodentiaRodentia

MiceMice

ProboscideaProboscidea

ElephantsElephants

LagomorphaLagomorpha

RabbitsRabbits

The The VertebratesVertebrates 12

ReviewReview

ChordatesChordates

Non-vertebrate ChordatesNon-vertebrate Chordates

VertebratesVertebrates

FishesFishes

AmphibiansAmphibians

RetilesRetiles

BirdsBirds

MammalsMammals

The The VertebratesVertebrates

Homework – Short Term

anthropoid arboreal

bipedalism culture

hominid hominoid

molecular clock mosaic evolution

Primate prosimian

Homework: Due Monday (end of class)

The The VertebratesVertebrates

Homework – Long Term

Read page 571

•Describe at least two examples of how products from animals are used in medicine.

•For extra credit – find some not listed on this page

Read 576 Connecting the Concepts

•State and support how YOU would measure which group of vertebrates (or invertebrates) are the ‘most successful.’

•Make sure you define successful and defend your position.