How Many Kingdoms?

1
How Many Kingdoms?
Extant
Multicellular Animals
Slime Molds
Archezoans
Archaebacteria
Myxozoans
Protozoans
Bryophytes
True Fungi
Green Algae
Chrysophytes
Tracheophytes
Euglenoids
Brown Algae
Bacteria
Red algae
Extinct
Long Time with Prokaryotes only
Original Cell
2
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 Reproductionfailure extinction Acclimatiza
tion-short term responses behavior Adaptation-lo
ng term responses evolution
3
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

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Animals probably evolved from a flagellated
protist similar to the choanoflagellates
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.
Of course the other required step is to eliminate
the chloroplasts of the choanoflagellate
(Chrysophyta!).
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Development or Evolution?
cleavage
2-layered acoelomate body plan
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Platyhelminthes Nematoda Annelida Mollusca Arthrop
oda
Origin of Mesoderm
Cnidarians
Echinodermata Hemichordata Chordata
Protostome Phyla
blastocoel
Deuterostome Phyla (except vertebrates)
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Evolution of Body Organization
Sponge, Cnidarian
Ectoderm Endoderm
Mesoderm
2-layered
3-layered
Acoelomate
Pseudocoelomate
Coelomate
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The Animal Clade
Extant
Chordata
This cladogram omits several smaller animal phyla!
Ancestral Choanoflagellate