D
I
V
E
R
S
I
T
Y
ANIMAL
Where are We?
What makes an Animal?
•
•
•
•
•
Eukaryotic
Heterotrophic
Multicellular
Diploid
Are motile at some stage
of the Life Cycle
Evolutionary History in Development
Why is embryonic development
important in our understanding of
evolution?
• Evolutionary
Developmental Biology
(“Evo-Devo”)
– Comparisons of
developmental characters
in different organisms can
often reveal ancestral
relationships
– Excellent characters for
use in building
phylogenies
Ernst Haeckel 1892
Development
Videos
• Development of the Blastula
• Gastrulation
Blastopore
Mouth: protostomes
Anus: deuterostomes
Triploblastic Development
Protostomes
(“mouth first”)
Blastopore=
mouth
Deuterostomes
(“mouth second”)
Blastopore=
anus
Body Plan: Symmetry
Symmetry
Radial Symmetry
Bilateral Symmetry
Symmetry Practice
Tissues
• Parazoa - group of organisms without true
tissues
• Eumetazoa - group of animals with true
tissues
Germ Layers
• Diploblastic
– Endoderm + ectoderm
• Triploblastic
– Endoderm + mesoderm + ectoderm
Triploblastic Animals
- Body Cavities
Red = ectoderm
Yellow = endoderm
Blue = mesoderm
Lophotrochozoa
Lophotrochozoa
Trochophore larvae
Lophophore
•Used for filter feeding
Ecdysozoa
Today’s Lab
• Work through all stations (use flowchart!)
• Identify unknowns in tank
• Show me your tree!
True Tissues?
Flow Chart
yes
no
Parazoa
Eumetazoa
Number of Germ Layers?
Asymmetry
two
three
Triploblastic
Diploblastic
Bilateral symmetry
Fate of blastopore?
Radial symmetry
mouth
Protostome
Acoelomate, Pseudocoelem, or Coelem
Which clade?
Lophotrochozoa
Trochophore larvae or lochophore
(or neither) ?
Ecdysozoa
anus
Deuterostome
Coelom