Bio 210: Lecture 8.Deuterostomes Tu 25 Feb 03 Lab 8.Animals3 1

More documents

Recommendations

Info

Bio 210: Lecture 8.Deuterostomes Tu 25 Feb 03• vertebral column• jointed, rigid endoskeletons• two pairs of appendages• anterior skull w/ large brain• large coelom• well-developed circulatory system11 Vertebrate Classes• Subphylum Vertebrata includes five classes:1. Osteicthyes ~ bony fishes2. Amphibia ~ amphibians3. Reptilia ~ reptiles4. Aves ~ birds5. Mammalia ~ mammals12 Vertebrate AnatomyFigure 33.713 Jaws, Legs & Lungsfig. 33-12• fish jaws evolved from anterior gill arches– for grasping & chewing prey• unjointed fins control swimming movements• lunglike sacs– supplemented gas exchange @ gills– swim bladders for buoyancy• bony fishes are diverse in size, shape & behavior14 Jawed FishesFigs 33.9-1115 From Water to Land• lobe-fins & lungfishes evolved jointed fins• led to amphibians, first vert’s to colonize land– via fresh water– protostomes colonized land via beaches• tetrapod = four-legged terrestrial vertebrates16 Amphibiansfig. 33-15• amphibians spend much of life in water• eggs must remain moist• 4,500 amphibian species alive today• three orders:– caecilians– anurans = frogs & toads– urodelans = salamanders17 Amphibian Eggs Need MoistureFigure 33.161819 Questions????20 AmniotesLab 8.Animals3 2
Bio 210: Lecture 8.Deuterostomes Tu 25 Feb 03• amniotes lay eggs protected by water-resistant shells & membranes, incubate them externally• reproduction not dependent on water• reptiles were first amniotes• modern reptiles include four lineages– turtles & tortoises– tuataras– snakes & lizards– crocodilians21 AmniotesFigure 33.1722 Reptile OriginsFigure 33.1823 Birds: Feathers & Flightstock photo24 Birdsfig. 33-21• amniotes• controversial origins ~175 mya• 9,600 extant species– feathers, wings, tail & wishbone– high metabolic rates– parental care– larger brains25 Mammalian Origins & Diversityfig. 33-22b• mammals evolved ~225 mya• eggs fertilized w/in females• embryos develop in utero• only mammals suckle young• Prototherians lay eggs– e.g. platypus, anteaters• two major groups of Therian mammals:– marsupials give birth to tiny young– eutherians bear well-developed young26 Marsupials & Eutheriansfig. 33-23 & 2427 ICE 8.1: Vertebrate Succession• Over time, reptiles replaced amphibians as the Earth’s s dominant terrestrial vertebrates. Why might this havehappened?• Later, when dinosaurs became extinct, mammals replaced reptiles as the Earth’s s dominant terrestrial vertebrates.Again, why?28 Primates & Human Origins• primates became adapted for arboreal life– opposable thumbs– nails rather than claws– forward eyes for binocular vision– small litters• split into two lineages:– prosimian includes lemurs, lorises & pottos– anthropoid includes tarsiers, monkeys, apes & humansLab 8.Animals3 3
Page 1: Bio 210: Lecture 8.Deuterostomes Tu

Bio 210: Lecture 8.Deuterostomes Tu 25 Feb 03 Lab 8.Animals3 1

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?