Animal Classification, Phylogeny
and Organization
Chapter 7
Why do we need Nomenclature?
Taxons
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Domain – Eubacteria, Archaea and Eukarya
Kingdom
Phylum
Class
Order
Family
Genus
Species
Question?
• How is DNA evidence of common ancestry?
VGT vs HGT
• Vertical Gene Transfer – genes transfer from
parent to offspring
• Horizontal Gene Transfer – genes transfer
from one species to another
• Base of the tree of life is a net
Animal Systematics
• Arranging animals into groups to show
evolutionary relationships
Vocabulary
Phylogeny
Body Symmetry
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What sort of symmetry do humans have?
Asymmetry
Bilateral symmetry
Radial symmetry
Cephalization
• How did evolution play a part in this?
Patterns of Development
• Major stages: fertilization, cleavage,
gastrulation, organogenesis
• Master control genes: Hox , Pax
Cleavage
• An embryonic stage that follows fertilization
• Characterized by rapid cell division
• Ends when cells form a hollow ball called a
blastula
Gastrulation
• Embryonic stage that follows cleavage and
blastula formation
• Cell movement generates additional inner
layers
Differentiation
• After gastrulation, development begins to
differentiate, depending on the organism
Vocabulary
• Ectoderm – gives rise to the epidermis
• Endoderm – gives rise to the tissue that lines
the gut cavity
• Mesoderm – gives rise to supportive (bone),
contractile (muscle) and blood cells
• Coelom – gives rise to viscera
Protostomes vs Deuterostomes