Animal Relationships PDF

Animal relationships Metazoa = Animalia Eumetazoa Bilateria Porifera Radiata (sponges) Cnidaria Themes:...

Animal relationships Metazoa = Animalia Eumetazoa Bilateria Porifera Radiata (sponges) Cnidaria Themes: 1) Mobility 2) Land (again) Kingdom Animalia Multicellular, eukaryotic, and heterotrophic 3 Porifera - Examples of early animals ! Notrue tissues ! Only a few cell types "Some totipotent ! Filter feeders "Fullof holes "Create current with choanocytes See 32.10 ! Very similar to choanoflagellates! 4 2  Animal relationships Metazoa = Animalia Eumetazoa Bilateria Porifera Radiata (sponges) Cnidaria Themes: 1) Mobility 2) Land (again) Kingdom Animalia Multicellular, eukaryotic, and heterotrophic 5 Eumetazoa ! Diploblastic ! Two cell layers "Endoderm (inside) "Ectoderm (outside) ! E.g. Cnidarians "Jellyfish, anemones, corals See Fig. 32.2 6 3  Eumetazoa ! Diploblastic ! Two cell layers "Endoderm (inside) "Ectoderm (outside) ! E.g. Cnidarians "Jellyfish, anemones, corals 7 Eumetazoa ! Diploblastic ! Two cell layers "Endoderm (inside) "Ectoderm (outside) ! Gastrulation ! Cnidarians "Jellyfish, anemones, corals 8 4  Cnidaria - Diploblastic animals ! Have a nervous system! ! Mobility! ! Radially symmetrical "Not very directional See Fig. 32.7 9 Animal relationships Metazoa = Animalia Eumetazoa Bilateria "Porifera" Cnidaria "Radiata" (sponges) Eumetazoa Gastrulation Nervous system, synpases Radial Symmetry 10 5  Bilateria - Origins and diversification ! The Cambrian “Explosion” ! Most modern phyla appear in “only” 40 million years 11 Animal relationships Metazoa = Animalia Eumetazoa Bilateria "Porifera" Cnidaria "Radiata" (sponges) Eumetazoa Gastrulation Nervous system, synpases Radial Symmetry 12 6  Bilateral symmetry and Cephalization ! Cephalization "Sense organs in front 13 Bilateral symmetry and Cephalization ! Cephalization ! Bilateral symmetry "Direction! 14 7  Bilateral symmetry and Cephalization ! Cephalization ! Bilateral symmetry "Direction! 15 Two Great Branches of the Bilaterian Tree ! Protostomes "E.g.Annelids, Arthropods, Molluscs ! Deuterostomes "E.g. Chordates 16 8  Two Great Branches of Bilaterian Tree ! Protostomes " Lophotrochozoa ! E.g. Annelids " Ecdysozoa ! E.g. Arthropods ! Deuterostomes " E.g. Chordates 17 Chordates “It’s a long way from Amphioxus” 18 9  Chordate Characteristics ! Notochord Unity of Plan "Structural support ! DorsalHollow nerve cord 33.5b "Elsewhere ventral ! Pharyngeal slits "Feeding,then breathing ! Muscular Tail "Propulsion 19 Chordates and Activity Level ! From ancestors with a relatively low metabolic rate, chordates evolve a highly active lifestyle!! ! Parallels among the Protostomes 20 10  Vertebrate Origins Urochordata Cephalochordata Vertebrata = Ascidian = Amphioxus ? 21 Amphioxus Our baseline for vertebrates ! Like vertebrates "Segmented "Can be fast ! But, lack "Well-developed brain "Heart "Gills/lungs ! And is small 22 11  Vertebrate Origins ! Great sense organs "Eyes, nose, hearing "(Protostomes too!) 23 Vertebrate Origins ! Great sense organs "Eyes, nose, hearing "(Protostomes too!) ! Jointed skeleton "(Arthropods too!) "e.g.Vertebral column 24 12  Vertebrate Origins ! Great sense organs "Eyes, nose, hearing "(Protostomes too!) ! Jointed skeleton "Vertebralcolumn "(Arthropods too!) ! Extreme cephalization "(Some protostomes, too!) 25 Vertebrate Relationships Gnathostomata Tetrapoda "Agnatha" "Fishes" Amphibians Amniotes Amniotic egg Jointed limbs Jaws 26 13  Vertebrate Relationships See 34.14 ! “Agnatha” "No Jaws ! Gnathostomata "Jaws #Evolve from gill arches #More effective feeding #Supports higher metabolism 27 Sharks and bony fishes ! Extremely successful in water "Most vertebrates are bony fishes "Wide range of habitats "No major invasions of land 28 14  Tetrapoda ! Amphibians, Reptiles, Birds, and Mammals ! Very successful on land ! Jointed appendages "More effective movement "(Arthropods too!) ! Amphibians still rely on water for reproduction "The bryophytes of the vertebrate world 29 Amniotes ! Much more successful on land than amphibians "Reptiles "Birds "Mammals ! Have dry scaly skin to reduce water loss (remember the plant cuticle?) 30 15  Amniotes ! Much more successful on land than amphibians "Reptiles "Birds "Mammals ! Amniotic egg 31 Amniotes ! Amniotic egg "Protection of embryo from environment Fig. 34.16 ! Amnion "Storage of wastes ! Allantois "Gas exchange ! Chorion 32 16  “Reptiles” ! Paraphyletic "Some closer to birds (e.g. croc) or mammals than to other reptiles ! Dominated land for a very long time "Overshadowed mammals for 140 million years! 33 Birds and Mammals Independently evolved a high metabolic rate! ! High body temperature "Insulation - feathers or fur ! Very efficient locomotion ! Very efficient respiration ! Four chamber heart "Complete separation of high/low oxygen blood 34 17  Birds and Mammals Independently evolved a high metabolic rate! Lizards Turtles Snakes Crocodiles Birds Mammals 4-chamber heart Warm blood ⇑ respiration Amniotic egg ⇑ circulation ⇑ locomotion 35 Birds ! Flight "Feathers ! Archaeopteryx intermediate in many ways "Teeth "Claws "Long, bony tail 36 18  Mammals ! Arose about 220 mya ! Primitively, laid eggs "Two species still do! ! Platypus, echidna ! Derived similarities include "Hair "Lactation "Three-bone middle ear 37 Summary ! Sponges: No true tissues ! Bilateria: Bilateral symmetry, cephalization ! Protostomes vs. Deuterostomes " Trend towards high energy lifestyle ! Chordate characteristics "Notochord, Dorsal hollow nerve cord, Pharyngeal slits, tail ! Gnathostomes have jaws "More efficient feeding 38 19  Summary - continued ! Tetrapods have jointed limbs "Better locomotion on land ! Amniotes have an amniotic egg "More resistant to drying ! Birds and mammals have independently evolved many features related to a very high metabolic rate "Effectiverespiration, circulation, locomotion, high body temperature, insulation 39 20