Animal Classification, Phylogeny and Organization

Chapter 7

Why do we need Nomenclature?

Taxons

• 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

• 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