1500_19_MammalianBodyPlan

1500_19_MammalianBodyPlan - BIO1500 W07 Mammalia (animals...

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Unformatted text preview: BIO1500 W07 Mammalia (animals like you and me) Sewall Wright (1889 - 1988) http://www.harvardsquarelibrary.org/unitarians/ wright-sewall.html MAMMALIA: basic facts 1) Monophyletic taxon that includes all tetrapods with hair and mammary glands 2) Includes largest vertebrates (blue whale: 33m, 136,000kg) 3) Smallest mammal is the Etruscan shrew with 4cm 4) Includes smartest vertebrates 3) ~5,800 species Savi's pygmy shrew, Etruscan shrew - SUNCUS ETRUSCUS http://www.americazoo.com/goto/index/mammals/48. h t m MAMMALIA: basic facts: mammalian radiation 1) Mammals diversified within short time window into a wide range of morphologies and ecological life histories Eastal (1999) summarizing Hedges et al (1996), Kumar and Hedges (1998) MAMMALIA: Monophyletic taxon Mammalia MAMMALIA: classification 1. Subclass/order Protheria: order Monotremata: platypus (1 species) and echidnas (3 species) 2. Subclass Marsupialia: pouched animals (>330 species) 3. Subclass Placentalia: placental mammals (>4,900 species) http://www.life.umd.edu/classroom/bsci338m/Lectures/phylogeny.jpg MAMMALIA: defining body plan traits 1) Mammary glands 2 ) Endothermy 3) Hair or fur 4) Four chambered heart 5) Specialized teeth 6) Synapsid skull 7) Three small ear bones 8) Neocortex region of the brain MAMMALIA: defining body plan traits: mammary glands 1) Female animals possess mammary glands for milk production to facilitate brood care Beluga whale off-spring neing fed at Shedd aquarium Chicago http://www.sheddaquarium.org/beluga_calf_update_07_25.html MAMMALIA: defining body plan traits: hair 1) Origin and structure: protein rich filament consisting of dead cells and keratin extending from hair follicle http://en.wikipedia.org/wiki/Image:Gray945.png MAMMALIA: defining body plan traits: hair 1) Taxonomic distribution MAMMALIA: defining body plan traits: endothermy 1) Endothermal animals maintain constant body temperature facilitating day time independent activity patterns. Endothermy is facilitated by hair forming insulating fur and more effective circulatory system driven by four chambered heart. MAMMALIA: defining body plan traits: hair 1) Origin and structure: protein rich filament consisting of dead cells and keratin extending from hair follicle MAMMALIA: defining body plan traits: hair: functions 1) Touch sensation MAMMALIA: defining body plan traits: hair: function 2) Regulation of body 2) Regulation temperature facilitating endothermy A sea otter has two types of fur. There are the long, coarse strands called guard hairs, and there are the shorter, finer hairs called underfur. When otters groom themselves, they are actually fluffing up their underfur to trap tiny air bubbles between each hair. These bubbles make a shield that blocks out the cold water. Sea otters must spend a great deal of time each day grooming themselves because if they don't groom, their fur gets matted and cannot hold the air bubbles. Then the water seeps through to their skin and the cold kills them. http://www.zoobooks.com/newFrontPag e/animals/virtualZoo/animals/s/seaotter s/fur.html MAMMALIA: defining body plan traits: hair 3 ) Camouflage MAMMALIA: defining body plan traits: hair 3) Camouflage and insulation http://www.adventures.ca/gasnet/74-2.htm MAMMALIA: defining body plan traits: hair 4) Social signals MAMMALIA: defining body plan traits: hair 4) Social signals http://www.neatorama.com/2006/05/02/elmar-weiss-windmill-beard/ MAMMALIA: defining body plan traits: hair 5) Defense (porcupine, hedgehog) MAMMALIA: defining body plan traits: hair: function 1) Regulation of body 1) Regulation temperature facilitating 37.5-39.8C endothermy 31C 36.8C MAMMALIA: defining body plan traits: four chambered heart 1) Endothermy is facilitated by more effective circulatory system driven by four chambered heart. MAMMALIA: defining body plan traits: four chambered heart 1) Endothermy is facilitated by more effective circulatory system driven by four chambered heart. MAMMALIA: defining body plan traits: endothermy 1) Body temperature regulation in cetaceans by counter current heat exchange MAMMALIA: defining body plan traits: bilobed lungs 1) Lungs MAMMALIA: defining body plan traits: bilobed lungs 1) Lungs MAMMALIA: defining body plan traits: bilobed lungs 1) Lungs http://encarta.msn.com/media_461517707/Generalized_Anatomy_of_a_Whale.html MAMMALIA: defining body plan traits: synapsid skull 1) Evolution of skull morphology http://rainbow.ldeo.columbia.edu/courses/v1001/8.html MAMMALIA: defining body plan traits: synapsid skull 1) Evolution of skull morphology http://rainbow.ldeo.columbia.edu/courses/v1001/8.html MAMMALIA: defining body plan traits: synapsid skull 1) Evolution of skull morphology http://rainbow.ldeo.columbia.edu/courses/v1001/8.html MAMMALIA: defining body plan traits: compartmentalized brain compartmentalized 1) Evolution of brain compartments MAMMALIA: defining body plan traits: skull 1) Evolution of brain compartments MAMMALIA: defining body plan traits: parapatric and sympatric nervous system MAMMALIA: defining body plan traits: acustic sense MAMMALIA: defining body plan traits: heterodont dentition 1) Teeth of one species differentiate into functionally diversified morphologies 2) Basic tooth types are grinding teeth, ripping teeth and chiseling teeth 3) Functional diversification of teeth played major role in mammalian radiation MAMMALIA: defining body plan traits: heterodont dentition Homodont dentition in reptiles and fish Homodont http://www.cnn.com/2004/WORLD/europe/02/20/offbeat.london.piranha.reut/ MAMMALIA: defining body plan traits: digestion of plants 1) Cows and other hoofed animals have specialized fourchambered somach for efficient fermentation of cellulose MAMMALIA: defining body plan traits: digestion of plants 1) Cows and other hoofed animals have specialized four-chambered somach for efficient fermentation of cellulose MAMMALIA: intestinal anatomy in non-fermenting herbivore MAMMALIA: intestinal anatomy in small carnivore MAMMALIA: intestinal anatomy in large carnivore MAMMALIA: digestive duct in omnivore MAMMALIA: defining body plan traits: kidney based excretion MAMMALIA: defining body plan traits: kidney based excretion MAMMALIA: defining body plan traits: kidney based excretion Functions of excretory system: 1 . Excretion 2. Filtration 3. Readsorption to blood 4. Secretion from blood ...
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