2/17/15&1&Animals&Homo sapiens Age of the dinosaurs First mammals First land vertebrates First land plant fossils Marine animals diversify Eon Neogene Paleogene Cretaceous Cenozoic Mesozoic Paleozoic Jurassic Triassic Permian Carboniferous Devonian Silurian Ordovician Cambrian Present Millions of years ago Period Era Phanerozoic 542 490 443 416 359 300 252 203 145 65 232/17/15&2&Radia0on&of&animals&~&530mya&during&Cambrian(Explosion(542;489&Million&Years&Ago&Cambrian&Fossils&Hallucigenia fossil (530 mya) 1 cm2/17/15&3&Opisthokonts Amoebozoans Archaeplastids Stramenopiles Alveolates Rhizarians Excavates Most diverse groups Groups with complex multicellularity Animals Choanoflagellates Ministerids Ichthyosporids Nucleariids Microsporidians Fungi Opisthokonta Most&closely&related&to&Choanoflagellates&Porifera (sponges) ANIMALIA ANIMALIA Fungi Choanoflagellates Choanoflagellates Multicellularity Diploblasty Triploblasty PROTOSTOMES BILATERIA LOPHOTROCHOZOA ECDYSOZOA Ctenophora (comb jellies) Cnidaria (jellyfish, corals, sea anemones) Acoela (acoels) Rotifera (rotifers) Platyhelminthes (flatworms) Annelida (segmented worms) Mollusca (snails, clams, squid) Protostome development Loss of coelom Segmentation DEUTEROSTOMES Cephalization, CNS, coelom Deuterostome development Segmentation Segmentation Radial symmetry (in adults) DEUTEROSTOMES Nematoda (roundworms) Arthropoda (insects, spiders, crustaceans) Echinodermata (sea stars, sand dollars) Chordata (vertebrates, tunicates) Phylogeny&of&&Major&Animal&Phyla&&Based&on&DNA&Sequence&Data.&Only&1.4&million&species&described&Es0mated&8&to&50&million&extant&species&&2/17/15&4&Key&traits:&&1. Mul0cellularity&• Cells&lack&cell&walls&• Have&an&extensive&extracellular&matrix&2. Heterotrophy&• Obtain&necessary&carbon&compounds&from&other&organisms&• Most&ingest&their&food&rather&than&absorbing&it&3. Mo0lity&• Mo ve&under&their&own&p ower&at&some&poin t&in &li fe&cycle&4. Nerve&cells&&&Muscle&cells&(except&in&Sponges)&Animals&Phylogeny&of&Mul0cellularity&Animals&are&a&monophyle4c&group&bilateral symmetry appears here2/17/15&5&Animal&Nervous&systems&Cephaliza4on:&Concentra0on&of&nervous&system&components&at&one&end&of&the&body&Evolved&independently&mul0ple&0mes&&&&!&Adapta0on&for&forward&movement&&&preda0on&Diversity&of&Sensory&Receptors&Examples:&Many&insects&see&UV&light&Nocturnal&snakes&see&at&night&by&sensing&infrared&light&Dogs&detect&very&low&odor&concentra0ons&2/17/15&6&Chemoreceptors&Detect&molecules&such&as&oxygen,&carbon&dioxide,&glucose,&amino&acids&The&basis&for&the&senses&of&smell&and&taste&Pheromones&&ma0ng&territory& alarm&trail&&Social&&Interac0ons&2/17/15&7&Mechanoreceptors&Respond&to&touch,&stretch,&pressure,&mo0on,&sound&Mechanoreceptors&Detec0on&of&mo0on&and&gravity&Ves0bular&system&in&mammals&2/17/15&8&Mechanoreceptors&Hearing&–&sensing&vibra0ons&Insect&antennae&Mechanoreceptors&Echoloca0on&2/17/15&9&Photoreceptors&Detect&light&Eye&cups&Compound&eye&Photoreceptors&Detect&light&2/17/15&10&Single;lens&eye&Convergent&Evolu0on&Photoreceptors&Detect&light&Other(receptors:(– Thermoreceptors&–&temperature&s0muli&– Pain(receptors((nociceptors)&–&pain&s0muli&– Electroreceptors&–&electrical&s0muli&&&2/17/15&11&Some&Feeding&Strategies&Suspension&or&&Filter&Feeding&Suc0on&&Feeding&Deposit&Feeding&Symmetry&in&Animals&Radial&Symmetry& Bilateral&Symmetry&2/17/15&12&Simple&phylogeny&Porifera&(Sponges)&• Sessile&• Benthic&• Asymmetric&&• No&true&0ssue&layers&&&Xestospongia+muta+(Caribbean)&w/&S.&McMurray&2/17/15&13&Figure&33.4&Spongocoel Pores Water flow Amoebocytes Spicules Flagellum Osculum Choanocytes Collar Food particles in mucus Choanocyte Phagocytosis of food particles Amoebocyte Azure vase sponge (Callyspongia plicifera) Suspension(Filter(feeders(Porifera:&&Anatomy&of&a&Sponge&2/17/15&14&Reproduc0on:&• Asexual&(to0potent&cells)&• Sexual&(male&&&female&gametes)&&!&Broadcast&spawning&Porifera&(Sponges)&Diploblasts:&Embryos&have&two&0ssues&layers&1. The&ectoderm&(“outside&skin)&&2. The(endoderm((inside&skin)&&(Most&cnidarians&are&diploblas0c(((((((((Evolu0on&of&0ssues&2/17/15&15&Embryonic&Organiza0on&of&Cnidarians&&&Bilaterians&Cnidarians:&Sea&Anemones,&Jellies,&Corals,&Hydra&• Radial&symmetry&• Diploblasts&w/&mesoglea&• Cnidocytes&• Reproduc0on&• Asexual&• Budding&• Fission&• Fragmenta0on&• Sexual&• Gametes&• Broadcast&Spawning&fertilization happens in the water2/17/15&16&Hydrosta0c&Skeletons&Cnidocytes&–&cells&containing&nematocysts&Photograph+by+David+Doubilet&Box&Jelly&Anemone&Hydra&2/17/15&17&Symbioses&with&photoautotrophs&Zooxanthellae&in&coral&polyps&Symbioses&with&photoautotrophs&Cassiopea&sp.&–&the&upside;down&jelly&2/17/15&18&Symbioses&with&vertebrates&Cnidarians:&colony&forma0on&Man&‘o&War&Fire&“coral”&&(a&colonial&hydrozoan)&Reef;forming&Coral&Colony&of&individuals&with&different&morphologies&2/17/15&19&Ctenophores&(Comb;Jellies)&Mnemiopsis+leidyi&<&5cm&long&Predator&of&plankton,&fish&eggs,&larvae&Invasive&species&in&Black&Sea&Major&ecosystem&impacts&• Diploblas0c&• Not&cnidarians&• No&s0nging&cells&• Move&using&cilia&Porifera (sponges) ANIMALIA ANIMALIA Fungi Choanoflagellates Choanoflagellates Multicellularity Diploblasty Triploblasty PROTOSTOMES BILATERIA LOPHOTROCHOZOA ECDYSOZOA Ctenophora (comb jellies) Cnidaria (jellies, corals, sea anemones) Acoela (acoels) Rotifera (rotifers) Platyhelminthes (flatworms) Annelida (segmented worms) Mollusca (snails, clams, squid) Protostome development Loss of coelom Segmentation DEUTEROSTOMES Cephalization, CNS, coelom Deuterostome development Segmentation Segmentation Radial symmetry (in adults) DEUTEROSTOMES Nematoda (roundworms) Arthropoda (insects, spiders, crustaceans) Echinodermata (sea stars, sand dollars) Chordata (vertebrates, tunicates) All&other&animals&are&triploblas0c&bilaterians.&&2/17/15&20&Embryonic&Organiza0on&of&cnidarians&and&bilaterians&Triploblasts&–&embryos&have&three&0ssue&layers&&1. The&ectoderm&2. The&endoderm&3. The(mesoderm((“middle&skin)&&&Evolu0on&of&mesoderm&was&important&&!&gave&rise&to&complex&muscle&0ssue&used&in&movement.&&In&general:&– Ectoderm&produces&the&covering&of&the&animal&(gives&rise&to&skin&and&nervous&system)&–