Animal kingdom Animal kingdom groups (phyla)groups (phyla)

What is an animal?What is an animal? Heterotroph (consumer, not decomposer)Heterotroph (consumer, not decomposer)

MulticellularMulticellular

EukaryoteEukaryote

No cell wall (unlike fungi, plants, and No cell wall (unlike fungi, plants, and bacteria)bacteria)

Specialized cells (unlike protists)Specialized cells (unlike protists)

Evolution of complexityEvolution of complexity Need: sense and chase down food sourceNeed: sense and chase down food source

Adaptation:Adaptation: nervous / motor systems nervous / motor systems

Need: break up food and absorb Need: break up food and absorb nutrientsnutrientsAdaptation:Adaptation: digestive system digestive system

Need: deliver oxygen to all cellsNeed: deliver oxygen to all cellsAdaptation:Adaptation: circulatory / respiratory circulatory / respiratory systemssystems

SpongesSponges

SpongesSponges

•O2 and food come in through

diffusion

•Filter feeds as an adult

SpongesSponges

Unique among animal groups –Unique among animal groups –

1)1) No symmetry in overall body planNo symmetry in overall body plan

2)2) No tissues (complex organization of No tissues (complex organization of cells)cells)

Sponge reproductionSponge reproduction

Sexual – release sperm into water (external Sexual – release sperm into water (external fertilization very common in aquatic animals)fertilization very common in aquatic animals)

Hermaphroditism – sponges have sperm AND Hermaphroditism – sponges have sperm AND eggs to increase the odds of reproductioneggs to increase the odds of reproduction

Offspring can swim to a new locationOffspring can swim to a new location

Asexual fragmentation also possibleAsexual fragmentation also possible

SpongesSponges

Simplest animalsSimplest animals

Possible colonial protozoan ancestorPossible colonial protozoan ancestor

CnidariansCnidarians

Sea anemone

Jellyfish

Evolution of radial Evolution of radial symmetrysymmetry

Definiton – can cut Definiton – can cut in equal halves in equal halves more than one waymore than one way

Ex: letters “O”, “X”Ex: letters “O”, “X”

Purpose – Purpose – extending tentacles extending tentacles equally in all equally in all directions (increase directions (increase food uptake)food uptake)

CnidarianCnidarian

Basic digestive systemBasic digestive system Also basic nervous system (nerve Also basic nervous system (nerve

net)net) OO22 still enters by diffusion still enters by diffusion

Revolution #1 – active Revolution #1 – active movementmovement

Filter feeding will not be sufficient for Filter feeding will not be sufficient for larger animalslarger animals

Filter feeding will not work on land or Filter feeding will not work on land or in airin air

2 major adaptations to help organisms 2 major adaptations to help organisms sense and move in their environmentsense and move in their environment

Adaptation #1) Body Adaptation #1) Body symmetrysymmetry

Bilateral symmetry allows for Bilateral symmetry allows for development of brain region in a development of brain region in a central location (head)central location (head)

Bilateral symmetry Bilateral symmetry cephalization cephalization

Adaptation #2: Body Adaptation #2: Body cavitycavity

CoelomCoelom is a space inside body (empty / is a space inside body (empty / fluid)fluid)

Two purposes in evolutionary history:Two purposes in evolutionary history:a) Short-term: something for muscles a) Short-term: something for muscles

to to push against to movepush against to move

b) Long-term: space for larger organsb) Long-term: space for larger organs

Not present in all animals (some have lost Not present in all animals (some have lost over evolutionary time)over evolutionary time)

Revolution #1 – active Revolution #1 – active movementmovement

Cephalization = “command center” Cephalization = “command center” to coordinate senses and movementto coordinate senses and movement

++

Coelom = support for muscle Coelom = support for muscle movementmovement

FlatwormsFlatworms

Planarian – not parasitic

Tapeworm – parasitic

Trends in flatwormsTrends in flatworms

No coelomNo coelom

Why? Many are parasiticWhy? Many are parasitic

OO22 and sugar absorbed in host’s and sugar absorbed in host’s intestineintestine

Tapeworm life cycleTapeworm life cycle

RoundwormsRoundworms

hookworm -- parasitic

Trends in roundwormsTrends in roundworms

Semi-developed coelom (moves a bit Semi-developed coelom (moves a bit more)more)

Can burrow through skin (walking Can burrow through skin (walking around barefoot), also enters around barefoot), also enters through contaminated foodthrough contaminated food

Not a problem in U.S.Not a problem in U.S.

Why not?Why not?

Food safety inspectionsFood safety inspections

Good sanitationGood sanitation

Medication widely availableMedication widely available

MollusksMollusks

Clam – 2 shells

Snail – 1 shell Squid – no shell

These are all in the same These are all in the same group!?!group!?!

inside of a clam

Mollusk traitsMollusk traits

Getting food – filter feeders (clams), Getting food – filter feeders (clams), grazers (snails), predators (slugs)grazers (snails), predators (slugs)

Getting OGetting O22 – gills in aquatic – gills in aquatic mollusks, primitive lung in snailsmollusks, primitive lung in snails

Open or closed circulatory systemOpen or closed circulatory system

Open vs. closedOpen vs. closed

Open

•No blood vessels

•Blood surrounds body’s organs, delivers O2

•Smaller animals

Closed

•Blood vessels

•Larger animals

ReproductionReproduction

Hermaphrodites (both mollusks and Hermaphrodites (both mollusks and segmented worms)segmented worms)

Aquatic – release sperm and eggs Aquatic – release sperm and eggs into waterinto water

Land – meet and swap sperm, Land – meet and swap sperm, fertilize eggs insidefertilize eggs inside

Segmented wormsSegmented worms

leech

earthworm

Segmented wormsSegmented worms Full coelom (full range of motion, Full coelom (full range of motion,

complex organs inside)complex organs inside)

OO2 2 – Gets O– Gets O22 directly from moist skin, directly from moist skin, closed circulatory system with hearts to closed circulatory system with hearts to

deliverdeliver

Food – blood (leeches), or dirt Food – blood (leeches), or dirt (earthworms)(earthworms)

Earthworms ruleEarthworms rule

Swallow dirt, filter out foodSwallow dirt, filter out food

Loosen soil, helps to aerate soil for Loosen soil, helps to aerate soil for plantsplants

Also fertilizes plants with castings Also fertilizes plants with castings (poop)(poop)

Leeches ruleLeeches rule

Two chemicals in saliva to help it Two chemicals in saliva to help it take blood from hoststake blood from hosts

a)a) AnestheticAnesthetic

b)b) Anti-coagulantAnti-coagulant

Revolution #2 - skeletonsRevolution #2 - skeletons

Structural support for larger bodies Structural support for larger bodies (remember, no cell walls in animal cells)(remember, no cell walls in animal cells)

Two varieties:Two varieties:

1) 1) ExoExoskeleton – outside body (arthropods)skeleton – outside body (arthropods)

2) 2) EndoEndoskeleton – inside body skeleton – inside body (echinoderms, (echinoderms,

chordates)chordates)

ArthropodsArthropodsFour main classes within this HUGE

phylum:

1)Arachnids

2)Crustaceans

3)Centipedes / millipedes

4)Insects

ArachnidsArachnids

Black widow Brown recluse

ArachnidsArachnids

Chigger (flea) Tick

Scorpion

CrustaceansCrustaceans

Crab Lobster

Barnacles

Many-footed onesMany-footed ones

Centipede Millipede

InsectsInsects

Fire ants

Wasp

Grasshopper

Arthropod traitsArthropod traits

Coelomate (I will also stop writing Coelomate (I will also stop writing this now)this now)

Segments still (possible connection Segments still (possible connection to segmented worms)to segmented worms)

ExoskeletonExoskeleton

ExoskeletonExoskeleton NOT the same as mollusk shellNOT the same as mollusk shell

Functions: 1) protection, 2) prevent Functions: 1) protection, 2) prevent water loss on land (waxy layer)water loss on land (waxy layer)

Problems: Heavy, growth requires Problems: Heavy, growth requires moltingmolting

Therefore: arthropods tend to be Therefore: arthropods tend to be smallersmaller

For respiration…For respiration…

System for collecting OSystem for collecting O2 2 (tracheal (tracheal tubes / spiracles)tubes / spiracles)

Open circulatory systemOpen circulatory system

Complex nervous systemComplex nervous systemSophisticated sensory / motor Sophisticated sensory / motor controlcontrol

Compound eye of a fruit flyCompound eye of a fruit fly

Arthropod reproductionArthropod reproduction

Internal fertilization (mating) in land Internal fertilization (mating) in land arthropodsarthropods

External fertilization in sea External fertilization in sea arthropodsarthropods

EchinodermsEchinoderms

sea star

sea urchin

sea cucumber

Echinoderm traitsEchinoderm traits

adults = adults = radialradial symmetry (live on symmetry (live on ocean floor)ocean floor) larvae are larvae are bilaterallybilaterally symmetric symmetric

endoskeletonendoskeleton

Echinoderm traitsEchinoderm traits

Food – variety of diet (some eat Food – variety of diet (some eat clams, some eat algae, some filter clams, some eat algae, some filter feed)feed)

Water vascular system (water Water vascular system (water instead of blood to carry Oinstead of blood to carry O22))

Reproduction typical in waterReproduction typical in water

ChordatesChordates

All chordatesAll chordates

Have Have notochordnotochord – precursor to – precursor to vertebral spinal column (semirigid, vertebral spinal column (semirigid, filled with fluid)filled with fluid)

Vertebrates replace this with a full Vertebrates replace this with a full spinal cordspinal cord

Some chordates are invertebrates stillSome chordates are invertebrates still

Invertebrate chordatesInvertebrate chordates

tunicatelancelet

Endoskeleton advantageEndoskeleton advantage

Organisms can grow larger with Organisms can grow larger with skeleton insideskeleton inside