2. All share four features: Allsharefour 2. (like theechinoderms) 1. .Otihhe bony - 4. cartilaginous fishes - 3. armored jawed fishes (extinct) - 2. jawless fishes - 1. • • • • havetailthatextendspastanus Embryos Embryos havepharynx withslits nervecord dorsal from develops supports Eight VertebrateClasses Chordata

Porifera Multicelled Multicelled 3. Vertebrata (thevertebrates) 3. Subphylum Vertebrata subphyla Two Radial Radial

Brain isencasedinprotectiveskull cartilage orbone of Have backbone () 2. Cephalochordata () 1. Urochordata Tissues Tissues Eight VertebrateClasses .Mmai - 8. Mammalia 7. Aves - - 6. Reptilia - 5. Amphibia

Platyhelminthes Three Subphyla triploblastic Bilateral Symmetry, Organs, triploblastic Bilateral Symmetry, Organs, Nematoda •Spiral •Spiral 1st forms • , , Complete gut Complete Complete gut Complete cephalized cephalized

Mollusca Coelomate Annelida •Radial cleavage 2nd forms •Mouth • Arhropoda

Echinodermata Nerve Cord Nerve Hollow Dorsal

Chordata Recent Findings Suggest: Trends in the of

1. Shift from notochord to

Reptiles 2. Nerve cord expanded into

? 3. Evolution of 2 problems 4. Paired evolved, gave rise to limbs 1. in separate ? 2. Birds in clade 5. evolved, gave rise to

Evolutionary Trends in Vertebrates Divergence of and Vertebrates

7. Diversity of Adaptations for land, air, and water 6. Amniotic 5. 4. Lungs

3. Jaws 1. : GNATHOSTOMES 2. Gills 2. and (2 chambers) CRANIATES CRANIATES 1. Paired Fins 3. Free-swimming 4. Molecular evidence suggests divergence 750 my ago 5. Undisputed vertebrates ~500 my old

Characteristics of Earliest Vertebrates Earliest Craniates 1. Small jawless 2. Bony , including vertebrae 530 million old : transition between invertebrate and ? 3. Bodies completely covered with bony armor plates -SCIENCE (2000) VOL. 287 4. Ate -floor 5. Brain imprints reveal many “modern” brain features: , , hindbrain

CRANIATES Extinct “agnathan” Evolution of Fishes Jawless Vertebrates: Lampreys, 488 mya 488 444 mya 444 540 mya 540 416 mya 416 359 mya 359

Subphylum Vertebrata Evolution of Jaws


Cartilaginous Fishes: Jawed Fishes Chondrichthyes

1. Most diverse and numerous group of vertebrates 1. Most are marine predators 2. Cartilaginous skeleton 2. Two classes: 3. Main groups: • Chondrichthyes (cartilaginous fishes) • Skates and rays • Osteichthyes (bony fishes) • (ratfishes) Subphylum Vertebrata Subphylum Vertebrata Chondrichthyes Cartilaginous fishes

Cartilaginous fishes Sharks and Rays

Rhinobatos productus Carcharadon shovelnose

Subphylum Vertebrata Bony Fishes: Cartilaginous fishes Class Osteichthyes

1. Includes 96 percent of living fish 2. Three subclasses: • Ray-finned fishes • Lobe-finned fishes MANTA RAY Manta birostris • fishes

Subphylum Vertebrata Subphylum Vertebrata Osteichthyes Bony fishes Ray-finned fishes “Common fishes”

Sebastes atrovirens Amphiprion melanopus kelp rockfish red and anemonefish Subphylum Vertebrata Subphylum Vertebrata

Sebastes chrysomelas Sebastes miniatus black and yellow rockfish vermillion rockfish

Subphylum Vertebrata Subphylum Vertebrata

Plectorhynchus goldmani Lutjanid sweet lips snapper

Subphylum Vertebrata Subphylum Vertebrata

Epinephelus tukula potato cod

Sebastes serranoides olive rockfish Subphylum Vertebrata Subphylum Vertebrata

camouflaged flatfish

Subphylum Vertebrata Subphylum Vertebrata

porcupinefish seahorse

Subphylum Vertebrata Subphylum Vertebrata

Lophius piscatorius Chauliodus sloani viperfish TETRAPODA Invasion of the Land: Amphibians Evolution of Amphibians

1. Lobe-finned fishes arose during the early 2. Used their fins to travel over land from pool to pool • and reproductive mode between fishes and reptiles • need water

Subphylum Vertebrata Subphylum Vertebrata

Latimeria menadoensis from fish to

Subphylum Vertebrata Early Amphibians

1. Lungs became more effective 2. Chambers of the heart became partially separated, making circulation more efficient - early amphibious tetrapod Modern Amphibians Living Groups

1. All require water at some stage in the ; 1. & Toads most lay eggs in water

2. Lungs are less efficient than those of other 2. vertebrates 3. serves as respiratory 3. Ceacilians

Subphylum Vertebrata Subphylum Vertebrata

Ambystoma mexicanum Mexican axolotl

Subphylum Vertebrata Subphylum Vertebrata

frogs Subphylum Vertebrata Subphylum Vertebrata

frog tadpoles Bufo marinus cane toad

Subphylum Vertebrata

1. Reptiles arose from amphibians in the O2 CO2 2. Adaptations to life on land • Tough, scaly skin • Internal fertilization • eggs • Water-conserving kidneys

amniotic egg

Reptilian Radiation

1. Adaptive radiation produced numerous lineages Posess many characteristics of both reptiles and mammals 2. Extinct groups include: • Therapsids (ancestors of mammals) • Marine plesiosaurs & ichthyosaurs • and Plesiosaurs Ichthyosaurs Up to 40 feet long

Fish-like reptiles 250 – 90 million ago

Living Reptiles

Four orders made it to the present day

Crocodilians Turtles Tuataras and

Turtles and Tortises Lizards and Snakes 1. Armorlike shell 1. Largest (95 percent of gland 2. Horny plates instead of teeth living reptiles) 3. Lay eggs on land 2. Most lizards are with small peglike teeth hollow fang 3. All snakes are with highly movable jaws Tuataras Tuatara

1. Only two living species 2. Live on islands off the coast of New Zealand 3. Look like lizards, but resemble amphibians in some aspects of their brain and in their way of walking Sphenodon guentheri

Subphylum Vertebrata Subphylum Vertebrata

Varanus Varanus goanna goanna

Subphylum Vertebrata Subphylum Vertebrata

python with amniotic eggs

Aipysurus laevis Python curtus brongersmai olive sea Subphylum Vertebrata Birds: Phylum Aves

1. Only birds have 2. Arose from reptilian ancestors • Feathers are highly modified reptilian scales

Alligator mississippiensis American alligator

Amniote Eggs Adapted for Flight

1. Like reptiles, birds produce amniote eggs 1. Four-chambered heart 2. Inside the egg, the is enclosed in a 2. Highly efficient membrane called the 3. Lightweight with 3. Amnion protects the embryo from drying out air spaces 4. Powerful muscles attach to the keel

From Dinosaurs to Birds From Dinosaurs to Birds


Opisthocomus hoazin hoatzin flying flying reptiles flying juvenile From Dinosaurs to Birds Evidence that Birds are Dinosaurs

scales • Birds and Reptiles have scales

• Birds and Reptiles lay eggs

• Birds and Reptiles have many similar bones feathers including , feet and

Scales and Feathers are Similar scales

Bird and Reptile Scales Bird and Reptile Feet

Bird leg Snake skin

Owl talons Deinonychus

Dinosaurs are NOT extinct! Subphylum Vertebrata

Alisterus scapularis Australian King Parrot

They are birds! Subphylum Vertebrata Subphylum Vertebrata

Casuarius casuarius Aptenodytes patagonicus King

Subphylum Vertebrata Mammals: Phylum Mammalia

1. Hair Ninox boobook 2. Mammary glands Southern Boobook 3. Distinctive teeth (Australian ) 4. Highly developed brain 5. Extended care for the young

The first ! Mammalian Origins

1. 200 million years ago, during the , gave rise to therapsids 2. Therapsids were the reptilian ancestors of mammals 3. The first mammals had evolved by the

Scratchus mammalus Three Mammalian Lineages Living

1. Monotremes 1. Three species • Egg-laying mammals 2. • Duck-billed • Pouched mammals • Two kinds of spiny anteater 3. Eutherians 2. All lay eggs • Placental mammals

Living Marsupials Living Placental Mammals

1. Most of the 260 species are native to Australia 1. Most diverse mammalian group and nearby islands 2. Young develop in mother’s uterus 2. Only the are found in 3. Placenta composed of maternal and fetal tissues; nourishes 3. Young are born in an undeveloped state and fetus, delivers , and removes wastes complete development in a permanent pouch on 4. Placental mammals develop more quickly than marsupials mother

Subphylum Vertebrata Subphylum Vertebrata

Monotremes Marsupials Placentals

mammal Three groupings of mammals Subphylum Vertebrata Subphylum Vertebrata

Dasypus novemcinctus

Dasypus novemcinctus armadillo

Subphylum Vertebrata Subphylum Vertebrata

Manis sp. Loxodonta africana

Subphylum Vertebrata Subphylum Vertebrata

Giraffa camelopardalis giraffe

Trichechus manatus latirostris manatee Subphylum Vertebrata Subphylum Vertebrata

Zalophus californianus Ailuropoda melanoleuca sea lion Giant Panda

Subphylum Vertebrata Subphylum Vertebrata

Ursus arctos Ursus arctos brown bear grizzly bear

Subphylum Vertebrata Subphylum Vertebrata


ocelot Subphylum Vertebrata Subphylum Vertebrata

Kangaroo and joey

Trichosurus vulpecula common brushtail possum

Subphylum Vertebrata Behavior

Subphylum Vertebrata Earliest

1. Primates evolved more than 60 million years ago during the Paleocene 2. First primates resemble tree shrews • Long snouts • Poor daytime vision baby orangutan From Primates to Humans Hominoids

1. Apes, humans, and extinct species of their lineages “Uniquely” human traits evolved 2. In and body , humans are closer through modification of traits that to apes than to monkeys evolved earlier, in ancestral forms 3. Hominids • Subgroup that includes humans and extinct humanlike species

Trends in Lineage Adaptations to an Leading to Humans Arboreal Lifestyle 1. Less reliance on smell, more on vision 1. During the , certain primates 2. Skeletal changes to allow bipedalism became adapted to life in trees 3. Modifications of to allow refined hand • Better daytime vision movements • Shorter snout 4. Bow-shaped and smaller teeth • Larger brain 5. Longer lifespan and longer period of dependency • Forward-directed • Capacity for grasping motions

First Hominids Australopiths

1. Earliest known is Ardipithecus ramidus 1. Earliest known is A. anamensis • Lived 4.4 million years ago in Africa 2. A. afarensis and A. africanus arose next • More apelike than humanlike 3. All three were slightly built (gracile) 2. Numerous australopiths evolved during the 4. Species that arose later, A. boisei and A. next 2 million years robustus, had heavier builds • Large face, protruding jaw, small 5. Exact tree is not known • Walked upright Hominid phylogeny Humans Arise

1. First member of the Homo is H. habilis 2. Lived in woodlands during late

Homo erectus Homo sapiens

1. Evolved in Africa 1. Modern man evolved by 100,000 years 2. Migrated into Europe and Asia about 1.5 ago million - 2 million years ago 2. Had smaller teeth and jaws than H. 3. Had a larger brain than H. habilis erectus 4. Was a creative toolmaker 3. Facial bones were smaller, skull was larger 5. Built fires and used furs for clothing

Homo Neanderthalensis Earliest Are African

1. Early humans that lived in Europe and 1. Africa appears to be the cradle of human evolution Near East 2. No human fossils older than 1.8 million years 2. Massively built, with large exist anywhere but Africa 3. Disappeared when H. sapiens appeared 3. Homo erectus left Africa in waves from 2 million 4. DNA evidence suggests that they did not to 500,000 years ago contribute to modern European populations Where Did H. sapiens Arise? Multiregional Model

1. Two hypotheses: 1. Argues that H. erectus migrated to many locations by about 1 million years ago • Multiregional model 2. Geographically separated populations gave rise to • African emergence model phenotypically different races of H. sapiens in 2. Both attempt to address both biochemical different locations and fossil evidence 3. flow prevented races from becoming species

African Emergence Model Genetic Distance Data

NEW GUINEA, AUSTRALIA 1. Argues that H. sapiens arose in sub- Saharan Africa PACIFIC ISLANDS SOUTHEAST ASIA 2. H. sapiens migrated out of Africa and into regions where H. erectus had preceded ARCTIC, NORTHEAST ASIA them NORTH, SOUTH AMERICA 3. Only after leaving Africa did phenotypic NORTHEAST ASIA differences between races arise EUROPE, MIDDLE EAST AFRICA

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