How Many Kingdoms? Extant 8 5 3 Extinct 2 Long Time with 1 Archaebacteria Archezoans Multicellular Animals Protozoans Green Algae Bryophytes Slime Molds Myxozoans True Fungi Bacteria Euglenoids Chrysophytes Brown Algae Red algae Tracheophytes 8 5 3 Extinct 2 1 Long Time with Prokaryotes only Original Cell

The Organism as a Unit of Life Looking Back at Bio 115 The Organism as a Unit of Life Cellular Structure (cell = unit of life)…one or many! Metabolism = Homeostasis (PSN, Resp, N2fix, ferment, etc.) Growth = irreversible change in size Reproduction…failure = extinction Acclimatization-short term responses = behavior Adaptation-long term responses = evolution

Animal Features Multicellular Eukaryotes Heterotrophic Ingestion Collagen Protein Connections Nerve and Muscle Tissues Diplontic (Gametic) Life History Gametes Oogamous with Flagellated Sperm Zygote to Blastula, perhaps Gastrulation Larval metamorphosis into Adult Ontogeny Recapitulating Phylogeny

Animals probably evolved from a flagellated protist similar to the choanoflagellates flagellum http://192.171.163.165/pil/Choanoflagellate_spp..jpg One step in this evolution is to become colonial. Here are the choanocytes of one of the simplest of sponges. Basically the most primitive animals. collar cell body http://ebiomedia.com/downloads/sponges.pdf Of course the other required step is to eliminate the chloroplasts of the choanoflagellate (Chrysophyta!).

Development or Evolution? cleavage zygote morula animal pole vegetal pole blastula blastocoel ectoderm endoderm blastopore archenteron blastopore 2-layered acoelomate body plan remnant of blastocoel

Origin of Mesoderm Cnidarians Protostome Phyla Deuterostome Phyla Platyhelminthes Nematoda Annelida Mollusca Arthropoda Origin of Mesoderm Cnidarians Echinodermata Hemichordata Chordata Protostome Phyla blastocoel archenteron Deuterostome Phyla (except vertebrates) blastopore mouth mouth anus

Evolution of Body Organization Sponge, Cnidarian spongocoel Planarian gastrovascular cavity Ectoderm Endoderm Mesoderm Nematode pseudocoelom 2-layered 3-layered digestive tract Acoelomate Annelid coelom Pseudocoelomate Coelomate

The Animal Clade Extant Platyhelminthes acoelomates Arthropoda Annelida Mollusca protostomia Nematoda Rotifera pseudo-coelomates Hemichordata Echinodermata Porifera parazoa Cnidaria Chordata deuterostomia coelomates radiata This cladogram omits several smaller animal phyla! bilateria eumetazoa (true tissues) loss of chloroplast, colonial organization Ancestral Choanoflagellate