LIFE 103 1st Edition Lecture 23 Outline of Last Lecture II. New instructor III. The ApproachIV. Animal knowledgeV. History of AnimalsVI. What are animals? VII. Characterizing animals a. Symmetryb. Developmentc. Body cavitiesOutline of Current Lecture I. AnnouncementsII. Protostomes vs. DeuterostomesIII. Trees IV. Porifera Current LectureAnnouncementsI. Final exam: Thursday, May 14 from 7:30-9:30 a.m. Protostomes vs. DeuterostomesII. Look at the patternsI. Cleavage I. Spiral and determinate vs. radial and indeterminateII. Determinate: each of the cells at the blastula stage is already determined (cell fate is already determined at the early stage)III. Indeterminate: not determined at the early stage II. Coelom formationI. Protostome: solid masses of mesoderm split and form coelomII. Deuterostome: folds of archenteron form coelom These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Three tissues: ectoderm, mesoderm, and endoderm III. All animals are tubes! But which end formed first? I. Protostomes: mouth develops first from blastopore III. Presence of coelom also importantI. Coelomate (can be both protostome and Deuterostome) (humans are one) II. Coelom: body cavity that helps with fluidity III. Acoelomate: animal lacking a coelom (ex: flatworms), mesoderm is solid and so there is no cavity IV. Pseudocoelomate: there is a cavity that is like a coelom, but it’s not a coelom because it is inside the mesoderm V. Sponges are completely disregarded with coeloms VI. Bilataria have the endoderm, mesoderm, and ectodermVII. Having a coelom or not does not really tell you any relationship between animals VIII. Protostome vs. Deuterostome will tell you evolutionary relationships, however Clicker question: is the presence or absence of a coelom a good indication of relationships among animal phyla? NO Animal taxa: invertebrates I (diversity) TreesI. Show: I. Evolutionary relationshipsII. Understand where important innovations or defining characteristics occurred III. Common descent II. Have: I. Most recent common ancestorII. Branch pointIII. Sister taxa III. Ex: I. Eumetazoa: true tissuesII. Metazoa: plus spongesIII. Bilateria: most animalsIV. What is a clade? I. Numbers represent most common ancestor II. All of the descendants of one common ancestor V. Ex: collar cell morphology and distribution + genetic evidence I. Choanoflagellates share a most recent common ancestor with Metazoa (animals)because of the cell type and genetic evidence VI. Use the information above on the distribution of a unique gene to defend the statement “choanoflagellates are not animals” I. Single-celled while animals are multicellularII. “CCD” domain is shared among all animals, can unite all animals because it is the common ancestor VII. Morphological and molecular data are combined to understand relationships among animal phyla VIII. Molecular (DNA) data have revolutionized our understanding (pg. 676 in text) Group Marine Sessile Motile Predatory Filter Feeding Porifera Yes Yes No No Yes Ctenophora Yes No Yes (cilia) Yes NoCnidaria Yes Yes Yes Yes YesPlacozoa Yes No Yes (flagella) Yes NoAcoela Yes No Yes (cilia) Yes No Rotifera No No Yes No Yes AcanthocephalaNo No Yes Yes NoCycliophora Yes No Yes Yes NoPorifera*- sponges (5,000-10,000 species)I. No true tissuesII. Filter feedingIII. No symmetryIV. Sessile V. Mostly marine VI. One of the most diverse groups Ctenophora- comb jellies (100-150 species)I. DiploblasticII. Predatory III. Radially symmetrical IV. Motile (via
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