Post on 17-Mar-2016
description
transcript
1st dinosaur
end of dinosaurs
1st reptiles1st amphibians1st 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
Reconstruction of the sea floor during the Vendian times when the Ediacaran organisms thrived
Ediacaran Fauna(600-540 MYBP)
end of Precambrian era
Ediacaran Seas
Mostly cnidarians and worms
Sea pens
Edicarian Fauna
Ancient Seas at the During the Cambrian Radiation (540 MYBP)
Burgess Shale
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)
An explosion of body plans
HallucigenaFeeding tentacles
spines
Similar to a sea urchin
Pikaia- earliest known chordate
Burgess Shale Fauna(540 MYBP)
Burgess Shale Fauna(540-530 MYBP
Anomalocaris
OpabiniaWiwaxia
Living Invertebrates
Phylogentic Relationships of Animals
Ancestral Protist
segmentation
true tissue
radial symmetrybilateral symmetry
Deuterostomes:eucoelom
Protostome: schizocoelem
pseudocoelom
Porifera
Cnideria
Platyhelminthes
Nematoda
Mollusca
Annelida Echinodermata
ChordataArthropoda
no true tissues
acoelom
Early Embryonic
Development of an Animal
Major Stages of Animal Development
• gametogenesis• fertilization• cleavage• blastula• gastrulation• differentiation and morphogenesis
Hypothetical Scheme for the Origin of Multicellularity in Animals
Protostome vs Deuterostome
Protostome- blastopore becomes mouthDeuterostome- blastopore becomes anus
Blastula
Blastopore
What is a Phylum?
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
Phylum Chordata
Major Body Plan Characteristics of Animals
• Symmetry• Primary Germ Layers• Gut Organization• Body Cavity• Segmentation• Skeletal Systems• Circulatory Systems• Appendages• Coloniality
Symmetry• Asymmetry• Radial Symmetry• Bilateral Symmetry
Symmetry
Radial Symmetry Bilateral Symmetry
Radial SymmetryJellyfish
Phylum Cnidaria
Pentamerous Radial Symmetry
Sea StarsPhylum Echinodermata
Bilateral SymmetrySlug
Phylum Mollusca
Bilateral Symmetry
SquidPhylum Mollusca
Primary Germ Layers
• None• Diploblastic• Triploblast
gut
ectoderm endoderm
mesoderm
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
The Formation of
Primary Germ Layers
The Formation of
Primary Germ Layers
Germ Layer Patterns
Diploblasticgut
ectoderm
endoderm
Diploblastic- two germ layersPhylum Cnidaria
Germ Layer Patterns
Triploblastic- 3 germ layersgut
ectoderm endoderm
mesoderm
acoelomate
Gut Organization
• No Gut• Blind Sac Gut• Complete Gut
No GutSponges
Phylum Porifera
No GutSponges
Phylum Porifera
Blind Sac GutPhylum Cnidaria
Complete Gut
Body Cavities
• Acoelomate• Eucoelomate• Pseudocoelomate
Body Cavities
Acoelomate- lacks cavity between gut and outer body wall
gut
ectoderm endoderm
mesoderm
Body CavitiesEucoelomate- body cavity
completely lined with mesoderm
gut
coelom
mesoderm
ectoderm
endoderm
Body Cavities
Pseudocoelomate- body cavity partially lined with mesoderm
gut
pseudocoelom
Advantages of aFluid-Filled Body
Cavity
• hydrostatic skeleton
• greater freedom for internal organs
• greater body size because of body fluid circulation
Segmentation
SegmentationCentipede
Phylum Arthropoda
SegmentationLobster
Phylum Arthropoda
Skeleton
Functions of the Skeleton
• supports basic body form
• protection of soft internal tissues and organs
• facilitates locomotion
Skeleton
• Hydrostatic Skeletons• Hard Skeletons
–Exoskeletons–Endoskeletons
Hydrostatic SkeletonSea Anemone
Phylum Cnidaria
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.
Hydrostatic Skeleton
EarthwormPhylum Annelida
ExoskeletonChiton
Phylum Mollusca
ExoskeletonStony Coral
Phylum Cnidaria
EndoskeletonsVertebrates
Phylum Chordata
Types of Appendages
Functions of Appendages
• locomotion
• feeding
• sensory
• protection
TentaclesSea Anemone
Phylum Cnidaria
Jointed AppendagesBee Appendages
Phylum Arthropoda
Circulatory Systems
Functions of Circulatory Systems
• transport of nutrients and metabolic wastes
• maintains water and solute balance
• defense against pathogens
Circulatory System
• None (simple diffusion)• Body Cavity Circulation• Closed Circulatory System• Open Circulatory System
No Circulatory SystemComb Jelly
Phylum Ctenophora
Circulation in a Moon JellyfishPhylum Cnidaria
Closed Versus Open Circulatory Systems
Nervous Systems
Functions of Nervous systems
• integration of animal behavior
• processing and interpretation of sensory information
• elicits external and internal responses
Types of Nervous Systems
Coloniality
ColonialityCoral
Phylum Cnidaria
ColonialitySea Fan
Phylum Cnidaria
Coloniality Man-of-War
Phylum Cnidaria
Polymorphism in the Portuguese Man- of-War