Animal Body Plans

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Animal Body Plans
Lecture 015
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Criteria for Evolutionary Development
Classification
Cellular organization Symmetry Coelom Digestive
system Segmentation Cephalization
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Kingdom Animalia
Symmetry Unorganized Radial Bilateral Cellular
organization Tissues, organs, systems
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Kingdom Animalia
coelom
digestive tube
Coelom Body cavity or not Digestive system None,
1 or 2 openings, how
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Kingdom Animalia
Segmentation Repetition of body
parts Cephalization Development of a head end
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What to Remember
Match with common name General characteristics Spe
cial evolutionary features General evolutionary
location
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Geologic Time Scale
Millions of Years
end of dinosaurs
1st dinosaur
1st reptiles 1st amphibians
1st land plants 1st fish
1st invertebrates
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• Ediacaran Fauna distinctive group of
  fossils dating from and existing
  only during Precambrian time
• 600 mya
• Australia's Ediacara Hills
• Environment shallow seas
• Description soft bodies worms, cnideria
• May be an evolutionary dead end

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Reconstruction of the sea floor during the
Vendian times when the Ediacaran organisms thrived
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Ediacaran Fauna(600-540 MYBP)end of Precambrian
era
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Ediacaran Seas
Sea pens
Mostly cnidarians and worms
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Edicarian Fauna
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Ancient Seas at the During the Cambrian Radiation
(540 MYBP)
Burgess Shale
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(No Transcript)
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Ancient Seas at the During the Cambrian
Radiation(540 MYBP)
Drawings based on fossils collected from Burgess
Shale in British Columbia, Canada
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Burgess Shale Fauna(540 MYBP)
Feeding tentacles
Hallucigena
spines
Similar to a sea urchin
An explosion of body plans
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Burgess Shale Fauna(540 MYBP)
Pikaia- earliest known chordate
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Burgess Shale Fauna(540-530 MYBP
Anomalocaris
Opabinia
Wiwaxia
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Living Invertebrates
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Phylogentic Relationships of Animals
Platyhelminthes
Porifera
Mollusca
Chordata
Arthropoda
Annelida
Cnideria
Nematoda
Echinodermata
pseudocoelom
segmentation
acoelom
Protostome schizocoelem
Deuterostomes eucoelom
radial symmetry
bilateral symmetry
true tissue
no true tissues
Ancestral Protist
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Early Embryonic Development of an Animal
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Major Stages of Animal Development

• gametogenesis
• fertilization
• cleavage
• blastula
• gastrulation
• differentiation and morphogenesis

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Hypothetical Scheme for the Origin of
Multicellularity in Animals
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Protostome vs Deuterostome
Blastula

• Protostome blastopore becomes mouth
• Deuterostome blastopore becomes anus

Blastopore
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What is a Phylum?
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Some Examples of Animal Phyla

• Phylum Cnidaria
• sea anemones, corals, jellyfish, man-of-wars
  hydroids
• Phylum Mollusca
• snails, slugs, chitons, clams, oysters, octopods
  squids
• Phylum Arthropoda
• spiders, scorpions, crabs, shrimp, insects
  centipedes
• Phylum Echinodermata
• sea stars, sea urchins, sea cucumbers sea
  lilies
• Phylum Chordata
• sea squirts, fish, amphibian, reptiles, birds
  mammals

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Phylum Chordata
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Major Body Plan Characteristics of Animals

• Symmetry
• Primary Germ Layers
• Gut Organization
• Body Cavity
• Segmentation
• Skeletal Systems
• Circulatory Systems
• Appendages
• Coloniality

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Symmetry

• Asymmetry
• Radial Symmetry
• Bilateral Symmetry

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Symmetry
Bilateral Symmetry
Radial Symmetry
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Radial Symmetry
JellyfishPhylum Cnidaria
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Pentamerous Radial Symmetry
Sea StarsPhylum Echinodermata
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Bilateral Symmetry
SlugPhylum Mollusca
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Bilateral Symmetry
SquidPhylum Mollusca
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Primary Germ Layers
Mesoderm

• None
• Diploblastic
• Triploblast

gut
Ectoderm
Endoderm
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Fates of the Primary Germ Layers

• Ectoderm
• hair, nails, epidermis, brain, nerves
• Mesoderm
• notochord (in chordates), dermis, blood vessels,
  heart, bones, cartilage, muscle
• Endoderm
• internal lining of the gut and respiratory
  pathways, liver, pancreas

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The Formation of Primary Germ Layers
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The Formation of Primary Germ Layers
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Germ Layer Patterns
Endoderm
Diploblastic
gut
Ectoderm
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Diploblastic- two germ layers
Phylum Cnidaria
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Germ Layer Patterns
Mesoderm
Triploblastic 3 germ layers
gut
Ectoderm
Endoderm
acoelomate
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Gut Organization

• No Gut
• Blind Sac Gut
• Complete Gut

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No Gut
SpongesPhylum Porifera
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No Gut
SpongesPhylum Porifera
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Blind Sac Gut
Phylum Cnidaria
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Complete Gut
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Body Cavities

• Acoelomate
• Eucoelomate
• Pseudocoelomate

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Body Cavities
Mesoderm
Acoelomate- lacks cavity between gut and outer
body wall
gut
Ectoderm
Endoderm
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Body Cavities
coelom
Mesoderm
Eucoelomate- body cavity completely lined with
mesoderm
gut
Ectoderm
Endoderm
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Body Cavities
pseudocoelom
Mesoderm
Pseudocoelomate body cavity partially lined with
mesoderm
gut
Endoderm
Ectoderm
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Advantages of aFluid-Filled Body Cavity

• hydrostatic skeleton
• greater freedom for internal organs
• greater body size because of body fluid
  circulation

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Segmentation
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Segmentation
CentipedePhylum Arthropoda
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Segmentation
LobsterPhylum Arthropoda
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Skeleton
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Functions of the Skeleton

• supports basic body form
• protection of soft internal tissues and organs
• facilitates locomotion

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Skeleton

• Hydrostatic Skeletons
• Hard Skeletons
• Exoskeletons
• Endoskeletons

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Hydrostatic Skeleton
Sea AnemonePhylum Cnidaria
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• Hydrostatic Skeleton
• A non compressible fluid held under pressure in a
  closed body compartment.
• Uses antagonistic muscles for movement.
• The gastrovascular cavity of the jellyfish acts
  as hydrostatic skeleton against which contractile
  cells can work.

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Hydrostatic Skeleton
EarthwormPhylum Annelida
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Exoskeleton
ChitonPhylum Mollusca
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Exoskeleton
Stony CoralPhylum Cnidaria
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Endoskeletons
Vertebrates Phylum Chordata
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Types of Appendages
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Functions of Appendages

• locomotion
• feeding
• sensory
• protection

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Tentacles
Sea AnemonePhylum Cnidaria
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Jointed Appendages
Bee Appendages Phylum Arthropoda
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Circulatory Systems
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Functions of Circulatory Systems

• transport of nutrients and metabolic wastes
• maintains water and solute balance
• defense against pathogens

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Circulatory System

• None (simple diffusion)
• Body Cavity Circulation
• Closed Circulatory System
• Open Circulatory System

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No Circulatory System
Comb JellyPhylum Ctenophora
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Circulation in a Moon Jellyfish
Phylum Cnidaria
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Closed Versus Open Circulatory Systems
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Nervous Systems
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Functions of Nervous systems

• integration of animal behavior
• processing and interpretation of sensory
  information
• elicits external and internal responses

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Types of Nervous Systems
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Coloniality
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Coloniality
CoralPhylum Cnidaria
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Coloniality
Sea FanPhylum Cnidaria
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Coloniality
Man-of-WarPhylum Cnidaria
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Polymorphism in the Portuguese Man- of-War