BIOL 200B 1st Edition Lecture 6 Chapter 33 Animal DiversityI. AnimalsII. Animal evolution; transitions in body plana. Origin of tissuesb. Origin of bilateral symmetryc. Origin of body cavityd. Origin of anus in bilateriansIII. Key adaptationsChapter 34 ProtostomesI. Protostomesa. Lophotrochozoansb. EcdysozoansII. Body planIII. Groups of Lophotr.IV. Groups of Ecdys.V. Adaptations for Terrestrial lifea. Locomotionb. Wings c. Reproduction ProtostomesMost animals are protostomesExtremely diverseVery abundantMonophyletic group2 Major Clades:1. Lophotrochozoaa. Diverse body plans, but not distinguishing synapomorphyb. Trochophore larvaeThese 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.c. Grow incrementally2. Ecdysozoaa. Clear synapomorphy – growth methodb. Grow by molting or shedding exoskeletonc. Reveals about the habitat use and diverse evolutionProtostome Body PlanEcdysozoans – reduced coelom (hemocoel) - Chitin – muscle attachment; protection; water conservation- Anthropod body planLophotrochozoan – general mollusk body plan- Mantle, visceral mass, muscular “foot”Groups of Lophotr.- Rotifera - Mollusca- Annelida- Platyhelmintheso Endoparasitic (tape-worm) o And free-living varieties o No coelom, no segmentation o No circulatory or respiratory systemGroups of Ecdys.- Nematodao Marine, fresh water, soil, and parasitic species o Pseudocoelom – hydrostatic skeleton o Covered by thick cuticle, molting of cuticle as the animal grows. o Mouth has piercing organs, stylets- Myriapoda- Arthropodao Most important o Insects, Chelicerates, Crustaceanso Arthropods first appear over 520 million years ago o Over 1 million living species have been described; more to be discoveredArthropod Traits:1. Segmented body – head, thorax, abdomen2. Chitin exoskeleton3. Jointed apendages4. Bodies are modularDiverse body plans allowed for filling variety of nichesAdaptations for terrestrial life:Water-to-land transitions are important because they open up entirely new habitats and new types of resources to exploit.Ancestral protostomes were aquatic- Exoskeleton- Eggs- Limbs- Lungs- High surface-area bodies- Thermal regulations- Mouth structureAdaptations for feeding:Diversity of feeding modes made possible by diversity of mouthparts.• suspension, deposit, liquid, and mass feeders • detritivores, herbivores, predators, parasitesAdaptations for locomotion:- Parapodia and/or chetae in annelids- Many legs of myriapodsOrigin of wings: insects were 1st to fly1. Independent origin hypothesisa. Body cross section wings2. Gill co-option hypothesisa. Gills wingsb. Developmental genetics experiments strongly supportAdaptations for reproduction:Metamorphosis: Consequences of metamorphosis - • planktonic larvae disperse (marine species) • larvae & adults do not compete for
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