1. Animal Classification
Phylogeny and Organization

2. Shared Characteristics
1.4 million species have been identified, 75% are animals
Based on shared evolutionary histories
Estimated 4-30 million species still to be identified
Taxonomy is the grouping of similar organisms based on the evolutionary relatedness of these Taxa (groups)
Nomenclature is the assigning of a descriptive name to each species

4. Binomial Nomenclature
Carolus Linnaeus developed the two word naming system
Used 5 taxonomic categories to which we have added 3 more
Domain, Kingdom, Phylum, class, Order, Family, Genus, Species. arranged from broadest to most specific
Common names vary between countries and some organisms have hundreds of names
Scientific names are derived from Latin or are Latinized and never vary

6. Domains and Kingdoms
Molecular Biological techniques such as sequencing nuclear and mitochondrial DNA
Genes and proteins of related animals are more similar
Gene products (proteins) and the sequence of nitrogenous bases in DNA are compared
Ribosomal RNA has been used to study the evolution of early life on earth
Studies of rRNA show three major evolutionary lineages all share a common ancestor 3.5 billion years ago,
Eubacteria- bacteria, most abundant organisms, 70 phylum level lineages, 7 are human pathogens
Archae- contains microbes distinct from bacteria, more similar to Eukarya genetically, cell wall structure distinct from bacteria, some are extremeophiles- high and low temperatures and pressures
Eukarya- compartmentalized cells, contain mitochondria and chloroplasts for energy, True multicellularity, tissues- organs- organ systems. Includes animals, Fungi, Plants, and six protist lineages

8. Animal Systematics
Arranging animals into groups that reflect evolutionary relationships
Group should include a single ancestor and all its descendants
Evolutionary Systematics – organisms closely related to an ancestor will resemble that ancestor. Homologies such as the bones in a birds wing and a human arm
Phylogenetic systematics (cladistics)- examine Homologies of recent origin and compare them to shared ancestral characteristics to determine when the group diverged

10. Embryonic Development

11. Embryonic Development

12. CLADISTICS

13. Patterns of organization
Reflect evolutionary changes in an animals body plan, does not always mean increased complexity, can include backtracking and failure (dead ends) but does show evolutionary trends
Symmetry- how parts of an animal are arranged around an axis
Asymmetry- the absence of a central point or equal distribution of a body. ex. Sponges
Radial Symmetry- organized around a central axis, may be Biradial or pentaradial . Ex. Ctenophorans and echonoderms
Bilateral Symmetry- animal divided into equal right and left halfs. Usually moves in one direction. Cephalization- development of brain and sense organs in anterior. Led to Paired Organs(spares)

15. RADIAL
BIRADIAL

17. Other Patterns of Organization
Unicellular organization- single cell characteristic of the Protista. Also called Cytoplasmic meaning all living functions are carried out by one cell
“Not Simple” provides for functions of locomotion, food acquisition, digestion, water and ion regulation, sensory and reproduction in a single cell
Cellular aggregates (Colonies) loose association of cells exhibit little cooperation or interdependence therefore not considered tissues. Show some division of labor, cells may be specialized for reproductive, nutritive, or structural functions (sponges, Porifera)

18. PROTISTA

19. Diploblastic Organization
Diploblastic- Ectoderm and endoderm embryonic tissue layers
Ectoderm gives rise to epidermis, skin and outer layer of body wall
Endoderm gives rise to gastrodermis tissue lines gut
Mesoglea between epi and gastro, may or may not contain cells.( Mesenchyme- when it contains cells)

21. Triploblastic Organization
Three embryological layers- Ectoderm and endoderm sandwiched around mesoderm layer which gives rise to supportive, contractile, and blood vessels
Triploblastic animals are divided into subgroups based on the presence and type of body cavity
Acoelomate-mesoderm tissues form a solid mass of cells between ecto and endo, some called parenchymal cells have specialized function (flatworms, Platyhelminthes, Rotifera)
Pseudocoelomate- has a body cavity not entirely lined by mesoderm. No mesenteries line the body cavity and connects to and holds organs in place (roundworms, Nematoda, Arthropoda)
Coelomate- body cavity surrounded by mesoderm. Peritoneum lines inner body wall continuous with serosa which suspends visceral structures. Mesenteries (segmented worms, Annelida, mollusca)

23. Higher Animal Taxonomy
Morphological and embryological evidence is being reinterpreted based on molecular rRNA comparisons
Four Phyla Mesozoa, Porifera, Cnidaria, and Ctenophora originated independently from other animals
Bilateral symmetrical animals are divided into two groups based on Embryological patterns and coelom formation
Protostomes- Platyhelminthes, Mollusca, Annelida, Arthropoda show similar developmental characteristics
Deuterostomes- Echinodermata, Hemichordata, and Chordata