L25 Animal phylogeny

tree of life, LUCA

the universal common core of the ribosome was finalized by LUCA, last universal common ancestor

endosymbiosis

wet from ancestral eukaryotic cell to eukaryotic cell with chloroplasts

great oxidation event

cyanobacteria photosynthesis; oxygen production

size matters

requires higher grade of organizatoin

key stages phylogeny/evolution

single cell

multicellular - cell differentiation (functions)

diploblast - gastrovascular cavity, ecotderm, endoderm

triploblast - formation archenteron, ectoderm, mesoderm, endoderm

quadruploblas - neural crest

celllar - chaonoflaggelates

colonial unicecullar organisms

porifera

sponges, divison of labour, tissues

diploblasts

endoderm and ecotderm, complete gut forms, no mesoderm created

diploblast

cnidaria and ctenophora

cnidaria (jellyfish and anemones)

• no anus, myoepithalial cells

ctenophora (comb jelly)

triploblast

3 germ layers

endoderm, ecotderm and mesoderm;

ectoderm

central nervous system, skin

mesoderm

muscles, bones, connective tissue

endoderm

gi-tract-lungs

triploblast - acoelomate

mesoderm fills blastocoel, spongy connective tissue

triploblast - pseudocoelomate

mesoderm lines ectoderm, blastocoel becomes pseudocoloem

triploblast - eucolomate

mesoderm fills blastocoel and then splits, mesoderms lines ectoderm and enteroderm, true coloem

triploblast - deuterostomes

blastopore becomes anus, mouth forms secondarilyt

triploblast - protostomes

blastopore becomes mouth, anus forms secondarily

protstomia; lophotrochozoa and exdysozoa

lophotrochozoa, lophophore, cilitated tentacles for filter feeding

ecydsozoa, ecydisis, cutcle molted and outer layer shed to grow

triploblast; lophotrochozoa

plathyhelmithes; flatworms

mollusca

• gastropoda, bivalvia, cephalopods

annelida, earthworms

triploblast, ecdysozoa

nematoda, rounds worms

arthrypoda, myriapoda (centi/milliped), chelicerata (spiders), crustacea (crabs), hexapoda (insects)

deuterostomia

radial cleavage, regulative embryo, blastopore becomes anus, mouth forms secondarily

protostomia

spiral cleavage, mosaic embryo, blastopore becomes mouth, anus forms secondarily

deuterostomia, echniodermata

echniodermate (stekelhuidigen) radial symmetry

deuterostomia; hemichordata

enteropneusta (acorn worm), pterobranchia