MARE 171

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Development and Evolution of Animals
MARE 171 Ms. Jen Turner
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The Animal Kingdom

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Animal Classification

• Nutritional Mode
• Cell Structure Function
• Reproduction Development

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Ancestry of Animal Groups
Cleavage -also called Segmentation 2
Developmental Modes Protostomes e.g.
flatworms, annelids, mollusks, arthropods Deutero
stomes e.g. echinoderms, vertebrates
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Ancestry of Animal Groups
Two Varying Types of Cleavage
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Ancestry of Invertebrate Groups
Indeterminate Development a.
Determinate Development a.
radial
Blastopore - Mouth
Blastopore - Anus
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Good Evening Ladies Germs

• A germ layer is a

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Onions have layersEmbryos have layers

• Germ Layers
• Endoderm
• -from which digestive tract lining, lungs
  liver (verts) develop
• Mesoderm
• -from which connective tissue, muscle, bone,
  urogenital circulatory systems develop
• Ectoderm
• -from which epidermal layers develop, for
  some, nervous system

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Number of Layers Differ

• Diploblastic ?
• Jellyfish, corals, comb jellies
• Triploblastic ?
• All other animals
• Excludes sponges ? no true tissues

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Embryonic Development
Triploblasts Coelom -body organs lie
bathed in body fluid -derived from mesoderm
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Ancestry of Animal Groups
Acoelomate Pseudocoelom True coelom -
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Embryonic Development
Acoelomate
Pseudocoelomate
Coelomate
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Ancestry of Animal Groups

• During Gastrulation Two kinds of True Coeloms
• Schizocoelom?
• 2. Enterocoelom?
• Schizocoeloms are found in animals known as
  PROTOSTOMATES
• Enterocoeloms are found in animals known as
  DEUTEROSTOMATES

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Ancestry of Animal Groups
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Body Symmetry
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Ancestry of Animal Groups
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