An Overview of Animal Diversity

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Laureen Owens
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Fig. 32-1 An Overview of Animal Diversity Multicellular Nutrition mode: Heterotrophic (ingestion) Cell structure & specialization

1 Fig An Overview of Animal Diversity Multicellular Nutrition mode: Heterotrophic (ingestion) Cell structure & specialization Tissues develop from embryonic layers Nervous & Muscle (unique) Lack cell walls Collagen structural protein Mostly sexual reproduction (2N)

Fig. 32-2-3 Reproduction and Development Blastocoel Cleavage Cleavage Blastula Endoderm Ectoderm Zygote

stage metamorphosis juvenile (not sexually mature) paedomorphic Homeobox direct body structure formation

2 Fig Reproduction and Development Blastocoel Cleavage Cleavage Blastula Endoderm Ectoderm Zygote Eight-cell stage Archenteron Gastrulation Gastrula Blastocoel Blastopore Cross section of blastula Larval stage metamorphosis juvenile (not sexually mature) paedomorphic Homeobox direct body structure formation (235 function genes) Homeodomain Transcriptional factors HOX genes regulates body form/pattern development

3 100 µm Fig RESULTS Wikramanayake & Martindale (2003) Site of gastrulation β-catenin Site of gastrulation

4 Gastrula A ectoderm B blastocoel C archenteron D endoderm E blastopore Triploblastic vs diploblastic

5 Fig Morphological & molecular evidence Collar cells ID DNA sequences & signaling/adhesion proteins Individual choanoflagellate Choanoflagellates OTHER EUKARYOTES Sponges Animals Other animals Collar cell (choanocyte)

6 Figure 32.4 Choanoflagellate Hydra Fruit fly CCD domain (only found in animals) Mouse

7 Figure 32.UN02 Era mya: Cambrian explosion 565 mya: Ediacaran biota 365 mya: Early land animals Origin and diversification of dinosaurs Diversification of mammals Neoproterozoic Paleozoic Mesozoic Cenozoic 1, Millions of years ago (mya)

8 Fig Neoproterozoic Era Ediacara 1.5 cm 0.4 cm (a) Mawsonites spriggi Bore hole (b) Spriggina floundersi 0.1 mm

9 Fig Paleozoic Era Cambrian explosion & Ediacaran decline pred-prey Increase O 2 HOX genes Hallucigenia fossil (530 mya)

10 Table 25-1 Animal diversity increased Punctuated mass extinctions

Fig. 32-7 Animals can be characterized by body plans Morphological and Developmental traits

11 Fig Animals can be characterized by body plans Morphological and Developmental traits Bilateral symmetry: Dorsal/ventral Anterior/posterior Cephalization (a) Radial symmetry (b) Bilateral symmetry

12 Body Cavities (a) Coelomate = true body cavity Coelom Digestive tract (from endoderm) Body covering (from ectoderm) Tissue layer lining coelom and suspending internal organs (from mesoderm) (b) Psuedocoelomate Digestive tract (from endoderm) Body covering (from ectoderm) Muscle layer (from mesoderm) (c) Acoelomate Body covering (from ectoderm) Wall of digestive cavity (from endoderm) Pseudocoelom Tissuefilled region (from mesoderm) Key Ectoderm Mesoderm Endoderm Most triploblastic animals possess a body cavity Coelom true body cavity (from mesoderm)

13 Body Cavities (a) Coelomate = true body cavity Coelom Body covering (from ectoderm) Key Digestive tract (from endoderm) Ectoderm Mesoderm Endoderm Tissue layer lining coelom and suspending internal organs (from mesoderm) Coelom functions: Cushions organs Hydrostatic skeleton Internal organs growth & develop Internal organs independent movement from outer body wall

14 Body Cavities (b) Pseudocoelomate = mesoderm & endoderm Body covering (from ectoderm) Pseudocoelom Muscle layer (from mesoderm) Key Digestive tract (from endoderm) Ectoderm Mesoderm Endoderm

15 Body Cavities (c) Acoelomate = lack body cavity Body covering (from ectoderm) Tissuefilled region (from mesoderm) Key Wall of digestive cavity (from endoderm) Ectoderm Mesoderm Endoderm

16 Fig Protostome development (examples: molluscs, annelids) Eight-cell stage Deuterostome development (examples: echinoderm, chordates) Eight-cell stage (a) Cleavage Key Ectoderm Mesoderm Endoderm Spiral and determinate Mesoderm Radial and indeterminate Coelom Archenteron Coelom Blastopore Solid masses of mesoderm split and form coelom. Anus Blastopore Mesoderm Folds of archenteron form coelom. Mouth (b) Coelom formation (c) Fate of the blastopore Digestive tube Mouth Mouth develops from blastopore. Anus Anus develops from blastopore.

17 Fig. 32-9a Protostome development (examples: molluscs, annelids) Eight-cell stage Deuterostome development (examples: echinoderms, chordates) Eight-cell stage (a) Cleavage Spiral and determinate Radial and indeterminate Platyhelminthes Identical twins & embryonic stem cells

Fig. 32-9b Protostome development (examples: molluscs, annelids) Deuterostome development (examples: echinoderms, chordates) Coelom Archenteron Coelom (b) Coelom

18 Fig. 32-9b Protostome development (examples: molluscs, annelids) Deuterostome development (examples: echinoderms, chordates) Coelom Archenteron Coelom (b) Coelom formation Key Ectoderm Mesoderm Endoderm Mesoderm Blastopore Blastopore Mesoderm Solid masses of mesoderm split and form coelom. Folds of archenteron form coelom.

19 Fig. 32-9c Protostome development (examples: molluscs, annelids) Deuterostome development (examples: echinoderms, chordates) Anus Digestive tube Mouth (c) Fate of the blastopore Key Ectoderm Mesoderm Endoderm Mouth Anus Mouth develops from blastopore. Anus develops from blastopore.

20 Fig Protostome development (examples: molluscs, annelids) Eight-cell stage Deuterostome development (examples: echinoderm, chordates) Eight-cell stage (a) Cleavage Key Ectoderm Mesoderm Endoderm Spiral and determinate Mesoderm Radial and indeterminate Coelom Archenteron Coelom Blastopore Solid masses of mesoderm split and form coelom. Anus Blastopore Mesoderm Folds of archenteron form coelom. Mouth (b) Coelom formation (c) Fate of the blastopore Digestive tube Mouth Mouth develops from blastopore. Anus Anus develops from blastopore.

21 Figure Views of animal phylogeny Porifera ANCESTRAL COLONIAL FLAGELLATE Metazoa Eumetazoa Bilateria Deuterostomia Protostomia Cnidaria Ctenophora Ectoprocta Brachiopoda Echinodermata Chordata Platyhelminthes Rotifera Mollusca Annelida Morphological & developmental data Arthropoda Nematoda

22 Figure Views of animal phylogeny Porifera ANCESTRAL PROTIST Metazoa 770 million years ago Eumetazoa 680 million years ago Points of agreement: Common ancestor Sponge basal animal Eumetazoan true tissues Bilateria most animals Molecular data Bilateria 670 million years ago Ctenophora Cnidaria Acoela Hemichordata Echinodermata Chordata Platyhelminthes Rotifera combine morphological, molecular & fossil data Deuterostomia Lophotrochozoa Ecdysozoa Ectoprocta Brachiopoda Mollusca Annelida Nematoda Arthropoda

Fig. 32-13 100 µm Lophophore Apical tuft of cilia Mouth

23 Fig µm Lophophore Apical tuft of cilia Mouth Anus (a) An ectoproct (b) Structure of a trochophore larva

24 The Diversification of Animals Five important points about the relationships among living animals are reflected in their phylogeny 1. All animals share a common ancestor 2. Sponges are basal animals 3. Eumetazoa ( true animals ) is a clade of animals with true tissues 4. Most animal phyla belong to the clade Bilateria 5. There are three major clades of bilaterian animals all of are invertebrates except Chordata

25 Fig. 32-UN1 Common ancestor of all animals Sponges (basal animals) Ctenophora Cnidaria Eumetazoa Metazoa True tissues Bilateral summetry Three germ layers Acoela (basal bilaterians) Deuterostomia Lophotrochozoa Ecdysozoa Bilateria (most animals)

What is an animal? Mul.cellular heterotrophs: feed by inges&on. How does this differ from plants, fungi, pro.sts?

What is an animal? Mul.cellular heterotrophs: feed by inges&on. How does this differ from plants, fungi, pro.sts? What is an animal? Carbohydrates stored as glycogen Polysaccharide of glucose (no, you