LIFE 103 1st Edition Lecture 26 Outline of Last Lecture II. EcdysozoaIII. NematodaIV. ArthropodaV. Characteristics of arthropodsVI. Arthropod diversityVII. ChelicerataVIII. Crustacea IX. Insecta X. Size of insectsOutline of Current Lecture I. Size of insectsII. VertebratesIII. Deuterostomia IV. EchinodermsV. Chordata VI. GnathostomesVII. OsteichthyesVIII. Lobe-fins IX. TetrapodsX. AmphibiansXI. AmniotesCurrent LectureWhy aren’t insects larger? These 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.I. Tracheoles that oxygen goes into cellsII. Size would make oxygen diffusion difficultIII. More oxygen in the air in the past why there were larger insects IV. Tracheae and tracheoles (essentially ductwork) allow air to circulate throughout the body—oxygen diffuses into the tissues near individual cells V. It’s an evolutionary “constraint” Vertebrates: Chordate evolution to amniotesDeuterostomiaI. Defined by molecular evidenceII. Deuterostome development I. Made up of Echinodermata (sea urchins), hemichordate (acorn worm), and chordate (tunicate) Echinoderms- starfish, sea urchins, sea cucumbers (~7,000 species)I. Predators and filter-feedersII. MotileIII. MarineChordata-chordates (~65,000 species)I. All feeding stylesII. Motile and sessileIII. Nearly all habitats and all elevations throughout the world ChordatesI. NotochordII. Dorsal hollow nerve chordIII. Pharyngeal slitsIV. Post-anal tailV. Most species diversity = in the vertebratesVI. Notochord- flexible rod in chordate embryos, becomes spine in vertebratesVII. Pharyngeal slits- develop into gills and eventually elements of the head, jaw, and ears VertebratesI. Duplication of Hox genes, possibly useful in increasingly complex body plansII. Bony vertebrae (usually surrounding the spinal cord) GnathostomesI. =Jawed mouthII. Jaws!III. More gene duplicationIV. Enhanced smell and visionV. Lateral line system- line of pores that detect pressure/motion and electromagnetic waves in the water Clicker question: identify the animal groups (on this tree), from least to most inclusive, that includes the species Homo sapiens-Milk(Amniotesmammalia)amniotic egg (AmniotesReptilia) limbs with digits (TetrapodsAmphibia)lobed fins (Lobe-finsDipnoi)lungs or lung derivatives (Ostelchthyans)jaws, mineralized skeleton (Ganthostomes)vertebrae (Vertebrates)notochord (Chordates) Mammalia-milk; amniotes-amniotic egg; tetrapods-limbs with digits; lobe-fins-fins with lobes; Osteichthyes-lungs or lung derivatives; gnathostomes-jaws; vertebrates-vertebrae; chordates-notochordOsteichthyes (majority of vertebrates) = “bony fish” I. Ossified endoskeleton II. Have lungs or lung derivatives III. Have a bony skeleton ActinopterygiiI. Ray-finned fishes, most diverse vertebrate group, over 30,000 speciesII. In all aquatic habitatsIII. From 8 mm to 11 m in lengthIV. Any possible aquatic niche Lobe-fines (Sarcopterygii)I. Lobed fins with bony and muscular support II. Have created the bones of our arms and legs TetrapodsI. 4 limbs with digitsII. Adults lack gillsIII. Vertebrae in neck permit head movement IV. Pelvic girdle fused to spine I. Helps with walking AmphibiaI. Frogs and toads- 5,000 speciesI. One of the most diverse vertebratesII. Global, many habitatsIII. Often specialized for leapingIV. Tadpoles = aquatic arvaeII. Salamanders and newts – 700 speciesI. Northern hemisphere, temperate predatorsII. Aquatic larvaeIII. Caecilians- 200 speciesI. Burrowing, soil-dwellingII. Tropical III. Viviparous- fertilize eggs in body until they develop in body and hatch out IV. Majority of groups live in tropics AmniotesI. Amniotic egg- specialized extraembryonic membrane (+shell)II. Ventilate with rib cage III. Not tied to marine habitats- can live anywhere IV. Birds are reptiles because they descended from dinosaursV. Reptilia + Mammalia ReptiliaI. 20,500 speciesII. Scales composed of keratinIII. Shelled eggs on land/ovoviviparity IV. Internal fertilizationV. Ectothermic + endothermic (cold blooded(dependent on behavior/environment)/ warm blooded)Evolution of limbless formsI. If a tetrapod lacks limbs, is it still a