LIFE 103 1st Edition Lecture 22 Outline of Last Lecture I. Atmospheric CO2II. Greenhouse effectIII. Evidence for present and future changeIV. Effects of changeOutline of Current Lecture II. New instructor III. The ApproachIV. Animal knowledgeV. History of AnimalsVI. What are animals? VII. Characterizing animals I. SymmetryII. DevelopmentIII. Body cavitiesCurrent LectureI. New instructor: Tanya DeweyI. Office: Yates 306II. Email: [email protected]. Office hours: Mondays 12-2, Fridays 12-1, and by appointment The ApproachI. So much to cover!II. Introduce issues and patternsIII. Pose and explore problemsIV. Use a comparative approachV. Assess understanding Animal Diversity and EvolutionThese 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.I. Fig. 26.21 II. Animals show up and are the sister taxon to fungiIII. What are animals = MetazoansIV. Zoo or zoa = animals (zoology) V. We tend to think of animals that are a lot like us VI. Can tell relative characteristics through a tree How well do we know animals? I. <1 million named speciesII. Estimates of the number of species up to 7.8 million totalIII. 86% of species on land are yet to be discoveredIV. 91% of marine species yet to be discovered V. Some examplesI. Vampire crab: commonly traded in aquaculture for over 10 yearsfound where they came from after being foundII. Frog in eastern Pennsylvania: new species because of different call (like a Leopardfrog)III. New walking stick speciesIV. Mushrooms in the deep oceans that could be an entirely new phylumVI. 70% of animals are insects = 3.5 lectures! (most of them are beetles) VII. Majority of species on the planet are animals History of Animals I. Prokaryotes and multicellular eukaryotes have been around for a really long timeII. Animals are a recently exploded speciesIII. Ediacaran OriginI. Animals evolved, including extant taxa and extinct formsIV. Cambrian Explosion: I. Oldest fossils of half of extant animal phylaII. Most major animal body plans evolveWhat are animals? = MetazoansI. MulticellularII. Ingestive heterotrophs I. Ingest food and digest it internallyIII. Lack cell walls, have structural proteins (such as collagen)IV. Unique, specialized cells: nerve and muscleV. Sexual reproductionVI. 2n dominantVII. Flagellated sperm, non-motile eggVIII. Most have larval stageIX. Cells are organized into tissues*I. Tissues are the next thing that organizes them II. Sponges do NOT have true tissuesIII. Eumetazoa: Includes all animals that have true tissues X. Conserved genes control development (Hox genes)*I. Regulate how an organism develops due to segmentationII. Hox (Homeobox) genes regulate morphogenesis XI. Zygote undergoes cleavage, forms blastula, gastrulationI. Cleavage: fertilized zygote cleaves into a eight cell stage that then becomes a blastulaII. Same size as egg III. Three tissues that form: ectoderm, mesoderm, and endoderm Clicker question: which of these evolutionary novelties is not a characteristic of (most) animals?Autotrophic Characterizing animalsI. By symmetry I. Bilateral beetles, humans, majority of animals can cut from anterior to posterior plane and get two sections that are equal II. Radial Ex: jellyfish, corals, can cut them in any plane and have two halvesIII. No symmetry (sponges)no two sides look alike II. For the most part, this aligns with the taxonomic groups on the tree III. Clade: everything with common ancestorIV. Species = taxon V. By developmental patternsI. Two broad types of patterns: i. Protostome developmentI. “Spiralia” cleavage is used here ii. Deuterostome developmentII. Also aligns well with the taxonomic groups on the tree VI. By body cavitiesI. Coelom = body cavity in metazoans, located between the gut and the body wall II. Protostomes = spiral and determinate cleavageIII. Deuterostomes (mouth second) = radial and indeterminate (cells can compensate if taken away) cleavage IV. How coelom is formed is different between the two as well V. What a coelom looks like: Endoderm, ectoderm, and mesoderm VI. Acoelomate (doesn’t have a cavity) vs. coelomate vs. pseudocoelomate (fake cavity, not really a