LIFE 103 1st Edition Lecture 22 Outline of Last Lecture I Atmospheric CO2 II Greenhouse effect III Evidence for present and future change IV Effects of change Outline of Current Lecture II New instructor III The Approach IV Animal knowledge V History of Animals VI What are animals VII Characterizing animals I Symmetry II Development III Body cavities Current Lecture I II New instructor Tanya Dewey I Office Yates 306 II Email tanya dewey gmail com Office hours Mondays 12 2 Fridays 12 1 and by appointment The Approach I II III IV V So much to cover Introduce issues and patterns Pose and explore problems Use a comparative approach Assess understanding Animal Diversity and Evolution 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 I II III IV V VI Fig 26 21 Animals show up and are the sister taxon to fungi What are animals Metazoans Zoo or zoa animals zoology We tend to think of animals that are a lot like us Can tell relative characteristics through a tree How well do we know animals I II III IV V VI VII 1 million named species Estimates of the number of species up to 7 8 million total 86 of species on land are yet to be discovered 91 of marine species yet to be discovered Some examples I Vampire crab commonly traded in aquaculture for over 10 years found where they came from after being found II Frog in eastern Pennsylvania new species because of different call like a Leopard frog III New walking stick species IV Mushrooms in the deep oceans that could be an entirely new phylum 70 of animals are insects 3 5 lectures most of them are beetles Majority of species on the planet are animals History of Animals I II III IV Prokaryotes and multicellular eukaryotes have been around for a really long time Animals are a recently exploded species Ediacaran Origin I Animals evolved including extant taxa and extinct forms Cambrian Explosion I Oldest fossils of half of extant animal phyla II Most major animal body plans evolve What are animals Metazoans I II III IV V VI VII VIII Multicellular Ingestive heterotrophs I Ingest food and digest it internally Lack cell walls have structural proteins such as collagen Unique specialized cells nerve and muscle Sexual reproduction 2n dominant Flagellated sperm non motile egg Most have larval stage IX X XI Cells are organized into tissues I Tissues are the next thing that organizes them II Sponges do NOT have true tissues III Eumetazoa Includes all animals that have true tissues Conserved genes control development Hox genes I Regulate how an organism develops due to segmentation II Hox Homeobox genes regulate morphogenesis Zygote undergoes cleavage forms blastula gastrulation I Cleavage fertilized zygote cleaves into a eight cell stage that then becomes a blastula II 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 animals I II III IV V VI 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 halves III No symmetry sponges no two sides look alike For the most part this aligns with the taxonomic groups on the tree Clade everything with common ancestor Species taxon By developmental patterns I Two broad types of patterns i Protostome development I Spiralia cleavage is used here ii Deuterostome development II Also aligns well with the taxonomic groups on the tree By body cavities I Coelom body cavity in metazoans located between the gut and the body wall II Protostomes spiral and determinate cleavage III 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 coelom