Taxonomic classification: The ordering and naming of organisms Carolus Linnaeus (mid-1700s) “God makes them, I name them”

BINOMIAL NOMENCLATURE Genus name & specific epithet Genus begins with _________ letter Genus & species underlined or in ______ E.g., Passer domesticus, P. turkistanicus HIERARCHICAL ORGANIZATION Taxon = group of related organisms

Hierarchical analogies: TAXON ANALOGY DOMAIN Continent KINGDOM Country PHYLUM State CLASS City ORDER Street FAMILY House No. GENUS ___________ SPECIES

SYSTEMATICS: Classification that reflects ________ relationships PHYLOGENY: The __________ history of taxa Presented as a phylogenetic tree Similar species grouped on branches

Phylogenetic tree

Branches of trees based in fundamental similarities 1) Body symmetry Asymmetry Ancestral multicellular animal

Asymmetry _____ regular shape sponge

Radial symmetry Sponges Ancestral multicellular animal _______ Asymmetry Ancestral multicellular animal

Multiple ________ cuts create similar parts Can also ____-shaped Radial Symmetry Multiple ________ cuts create similar parts Can also ____-shaped Moon jelly

Longitudinal axis

Bilateral symmetry Jellies Sponges Ancestral multicellular animal Radial symmetry Asymmetry ________ symmetry Ancestral multicellular animal

Bilateral Symmetry Have left and right sides Only equally divisible along ______ plane

ANTERIOR versus POSTERIOR Front end versus rear end Anterior Posterior

Clam

DORSAL versus VENTRAL Upper versus lower ______ Dorsal Ventral

Body segmentation Like slices of bread 1) Unsegmented Roundworms Flatworms ___________ Jellies Sponges Radial symmetry Asymmetry Bilateral symmetry Ancestral multicellular animal

2) External segmentation Roundworms Flatworms Jellies Sponges Radial symmetry unsegmented _______ segmentation Asymmetry Bilateral symmetry Ancestral multicellular animal

Obvious, like a ____ of bread Segmented worms Arthropods

External segmentation 3) Internal segmentation Roundworms Arthropods Segmented worms Flatworms Jellies Sponges Radial symmetry External segmentation Asymmetry Bilateral symmetry ______ segmentation Ancestral multicellular animal

Must look ______ Endoskeleton, muscles, nerves

External segmentation Skeleton 1) Exoskeleton Roundworms Segmented worms Arthropods Flatworms Jellies __________ Sponges Radial symmetry External segmentation Asymmetry Bilateral symmetry Internal segmentation Ancestral multicellular animal

Exoskeleton Hard skeleton outside, muscles inside E.g., insects, crustaceans

External segmentation 2) Endoskeleton Roundworms Segmented worms Arthropods Flatworms Jellies Exoskeleton Sponges Radial symmetry External segmentation Asymmetry Bilateral symmetry Internal segmentation Endoskeleton Ancestral multicellular animal Chordates

Endoskeleton Hard skeleton inside, muscles outside

“SHELLS” Neither endo- or exo-skeletons Snails and clams = _____ Turtles and crustaceans= ________ Protists & sea urchins = _____ Chiton shells have 8 plates Dorsal view Ventral view