Criteria for Evolutionary Development & Classification
Cellular organization
Symmetry
Coelom
Digestive system
Segmentation
Cephalization
Kingdom Animalia
Symmetry
Unorganized
Radial
Bilateral
Cellular organization
Tissues, organs, systems
Coelom
Body cavity or not
Digestive system
None, 1 or 2 openings, how
Kingdom Animalia coelom
digestive tube
1st dinosaur
end of dinosaurs
1st reptiles1st amphibians
1st land plants1st fish
1st invertebrates
Millions of YearsGeologic Time Scale
Ediacaran Fauna: distinctive group of fossils dating from and existing only during Precambrian time
• The fauna arose about 600 mya.
• Named for Australia's Ediacara hills, where it was first discovered. Such fossils were later found to be widespread.
• These animals lived in shallow seas and had soft bodies that bear little resemblance to later life forms, and were about 1 m in length.
• May be an evolutionary dead end
Ediacaran Fauna(600-540 MYBP)
end of Precambrian era
Ediacaran Fauna(600-540 MYBP)
end of Precambrian era
Ancient Seas at the During the Cambrian Radiation
(540 MYBP)
Ancient Seas at the During the Cambrian Radiation
(540 MYBP)
Drawings based on fossils collected from Burgess Shale in British Columbia, Canada
Burgess Shale Fauna(540 MYBP)
Burgess Shale Fauna(540 MYBP)
An explosion of body plans
HallucigenaFeeding tentacles
spines
Similar to a sea urchin
Phylogentic Relationships of AnimalsPhylogentic Relationships of Animals
Ancestral Protist
segmentation
true tissue
radial symmetry
bilateral symmetry
Deuterostomes:eucoelom
Protostome: schizocoelem
pseudocoelom
Porifera
Cnideria
Platyhelminthes
Nematoda
Mollusca
AnnelidaEchinodermata
ChordataArthropoda
no true tissues
acoelom
Major Stages of Animal Development
Major Stages of Animal Development
• gametogenesis
• fertilization
• cleavage
• blastula
• gastrulation
• differentiation and morphogenesis
• gametogenesis
• fertilization
• cleavage
• blastula
• gastrulation
• differentiation and morphogenesis
Hypothetical Scheme for the Origin of Multicellularity in Animals
Hypothetical Scheme for the Origin of Multicellularity in Animals
Fig. 32-9aFig. 32-9a
Eight-cell stage Eight-cell stage
Spiral and determinate Radial and indeterminate
Protostome development(examples: molluscs,
annelids)
Deuterostome development(examples: echinoderms,
chordates)
Cleavage
Protostome vs Deuterostome
Fig. 32-9bFig. 32-9b
Coelom
Protostome development(examples: molluscs,
annelids)
Deuterostome development(examples: echinoderms,
chordates)
Key
EctodermMesoderm
Endoderm
MesodermMesoderm
Coelom
Archenteron
Blastopore Blastopore
Solid masses of mesodermsplit and form coelom.
Folds of archenteronform coelom.
Coelom formationProtostome vs Deuterostome
Fig. 32-9cFig. 32-9c
Anus
Protostome development(examples: molluscs,
annelids)
Deuterostome development(examples: echinoderms,
chordates)
Anus
Mouth
Mouth
Digestive tube
(c) Fate of the blastopore
Key
EctodermMesoderm
Endoderm
Mouth develops from blastopore. Anus develops from blastopore.
Fate of BlastoporeProtostome vs Deuterostome
Some Examples of Animal PhylaSome 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
• 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
Major Body Plan Characteristics of Animals
Major Body Plan Characteristics of Animals
• Symmetry
• Primary Germ Layers
• Gut Organization
• Body Cavity
• Segmentation
• Skeletal Systems
• Circulatory Systems
• Appendages
• Coloniality
• Symmetry
• Primary Germ Layers
• Gut Organization
• Body Cavity
• Segmentation
• Skeletal Systems
• Circulatory Systems
• Appendages
• Coloniality
SymmetrySymmetry
• Asymmetry
• Radial Symmetry
• Bilateral Symmetry
• Asymmetry
• Radial Symmetry
• Bilateral Symmetry
SymmetrySymmetry
Radial Symmetry Bilateral Symmetry
Pentamerous Radial Symmetry
Pentamerous Radial Symmetry
Sea StarsPhylum Echinodermata
Sea StarsPhylum Echinodermata
Primary Germ LayersPrimary Germ Layers
• None
• Diploblastic
• Triploblast
• None
• Diploblastic
• Triploblast
gut
ectoderm endoderm
mesoderm
Fates of the Primary Germ LayersFates 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
• 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
Body CavitiesBody Cavities
• Acoelomate
• Eucoelomate
• Pseudocoelomate
• Acoelomate
• Eucoelomate
• Pseudocoelomate
Acoelomate
(c) Acoelomate
Body covering(from ectoderm)
Wall of digestive cavity(from endoderm)
Tissue-filled region(from mesoderm)
Pseudocoelomate
Pseudocoelom
Body covering(from ectoderm)
Muscle layer(frommesoderm)
Digestive tract(from endoderm)
Eucoelomate
CoelomBody covering(from ectoderm)
Digestive tract(from endoderm)
Tissue layerlining coelomand suspendinginternal organs (from mesoderm)
Advantages of aFluid-Filled Body
Cavity
Advantages of aFluid-Filled Body
Cavity
• hydrostatic skeleton
• greater freedom for internal organs
• greater body size because of body fluid circulation
• hydrostatic skeleton
• greater freedom for internal organs
• greater body size because of body fluid circulation
Gut OrganizationGut Organization
• No Gut
• Blind Sac Gut
• Complete Gut
• No Gut
• Blind Sac Gut
• Complete Gut
Functions of the SkeletonFunctions of the Skeleton
• supports basic body form
• protection of soft internal tissues and organs
• facilitates locomotion
• supports basic body form
• protection of soft internal tissues and organs
• facilitates locomotion
SkeletonSkeleton
• Hydrostatic Skeletons
• Hard Skeletons–Exoskeletons
–Endoskeletons
• Hydrostatic Skeletons
• Hard Skeletons–Exoskeletons
–Endoskeletons
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.
Functions of AppendagesFunctions of Appendages
• locomotion
• feeding
• sensory
• protection
• locomotion
• feeding
• sensory
• protection
Jointed AppendagesJointed Appendages
Bee AppendagesPhylum ArthropodaBee Appendages
Phylum Arthropoda
Functions of Circulatory SystemsFunctions of Circulatory Systems
• transport of nutrients and metabolic wastes
• maintains water and solute balance
• defense against pathogens
• transport of nutrients and metabolic wastes
• maintains water and solute balance
• defense against pathogens
Circulatory SystemCirculatory System
• None (simple diffusion)
• Body Cavity Circulation
• Closed Circulatory System
• Open Circulatory System
• None (simple diffusion)
• Body Cavity Circulation
• Closed Circulatory System
• Open Circulatory System
Functions of Nervous systemsFunctions of Nervous systems
• integration of animal behavior
• processing and interpretation of sensory information
• elicits external and internal responses
• integration of animal behavior
• processing and interpretation of sensory information
• elicits external and internal responses