{"id":597,"date":"2015-08-16T16:38:32","date_gmt":"2015-08-16T16:38:32","guid":{"rendered":"http:\/\/sites.msudenver.edu\/haysc\/?page_id=597"},"modified":"2015-08-16T16:38:32","modified_gmt":"2015-08-16T16:38:32","slug":"answers-1-bio-3220-introduction-to-comparative-anatomy-and-the-vertebrates","status":"publish","type":"page","link":"https:\/\/sites.msudenver.edu\/haysc\/biology-courses\/comparative-vertebrate-anatomy-bio-3220\/answers-1-bio-3220-introduction-to-comparative-anatomy-and-the-vertebrates\/","title":{"rendered":"Answers-1, BIO 3220, Introduction to Comparative Anatomy and the Vertebrates"},"content":{"rendered":"

A. INTRODUCTION TO COMPARATIVE VERTEBRATE ANATOMY<\/strong><\/p>\n

1. Define comparative vertebrate anatomy, morphology, phylogeny, embryology.
\nAnatomy \u2013 description and observation of structures
\nMorphology \u2013 relating and interpreting structures
\nPhylogeny \u2013 evolutionary history of a group or structure
\nEmbryology \u2013 study of development of structures in embryos<\/p>\n

2. Contrast homology and analogy. Give an example of homoplasty.
\nHomology \u2013 shared common ancestry; related
\nAnalogy \u2013 shared common function
\nHomoplasty \u2013 shared anatomy, but not homologous; for example, the wing of a bird and the wing of a grasshopper<\/p>\n

3. Discuss adaptation and preadaptation. Briefly discuss Darwin\u2019s theory of natural selection.
\nAdaptation \u2013 function first, then form; for example, there was food on land, so a fish with \u201cfunny fins\u201d crawled to it
\nPreadaptation \u2013 form first, then function; for example, fish with \u201cfunny fins\u201d had fins first and came to land
\nTheory of natural selection – natural selection is often described as \u201csurvival of the fittest;\u201d it maintains that the organisms best suited to survive in their environment are more likely to reproduce and pass their genetic material to the next generation, while those with less advantageous traits are less likely to survive long enough to reproduce<\/p>\n

4. Compare and contrast divergent, convergent, parallel and organic evolution.
\nDivergent \u2013 the evolutionary pattern in which two related species gradually become increasingly different; often occurs when closely related species diversify to new habitats
\nConvergent \u2013 the pattern that takes place when species of different ancestry begin to share analogous traits because of a shared environment or other selection pressure; for example, whales and fish have some similar characteristics since both had to evolve methods of moving through the same medium, water
\nParallel \u2013 the pattern that occurs when two species evolve independently of each other, maintaining the same level of similarity; usually occurs between species that do not occupy the same or similar niches in a given habitat
\nOrganic \u2013 a concept that embodies the belief that existing animals and plants developed by a process of gradual, continuous change from previously existing forms<\/p>\n

5. What is a vestigial structure? A rudimentary structure?
\nVestigial \u2013 structures better developed in ancestors
\nRudimentary \u2013 structures better developed in descendents<\/p>\n

6. Define ontogeny.
\nOntogeny \u2013 an individual\u2019s life history from fertilization to death<\/p>\n

7. Describe heterochrony \u2013 specifically paedogenesis, neoteny, and paedomorphosis.
\nHeterochrony \u2013 changes in relative rates of development
\nPaedogenesis \u2013 gonads develop fast
\nPaedomorphosis \u2013 immature features of ancestor become characteristics of future species; for example, the gills of mudpuppies
\nNeoteny \u2013 type of paedomorphosis in which larval features are retained in the individual
\nB. VERTEBRATE CHARACTERISTICS<\/strong><\/p>\n

1. Review the vertebrate taxonomy from your zoology course.<\/p>\n

2. Name four main chordate features.
\nDorsal hollow nerve cord, notocord, pharyngeal gill slits\/arches, postanal tail<\/p>\n

3. Theorize the origin of the vertebrates.
\nThrough comparative embryology, scientists now believe that the chordates arose from a primitive sessile-benthic arm-feeding echinoderm. Tunicates are small marine invertebrate chordates quite common today; they may hold the key to vertebrate origins. Tunicates have a sessile adult stage in which they are filter-feeders with gill slits but no notochord or dorsal nerve tube. Tunicate larvae, though, are free-swimming filter-feeders; they are characterized by a notochord and dorsal nerve tube lost later when they metamorphose into sessile adults. It is possible that a tunicate-like organism evolved by way of neoteny into a free-swimming adult chordate. In this case, the juvenile features of tunicate-like organisms (notochord, dorsal nerve tube, and swimming ability) may have been evolutionarily retained in the succeeding chordates. The lancelet is a chordate with a free-swimming adult stage, and also a filter-feeding bottom-dweller. We may predict, then, that the first vertebrates were free-swimming, bottom-dwelling filter feeders, probably during the Ordovician Period, 500 million years ago.<\/p>\n

4. Discuss vertebrate characteristics.
\nVertebral column \u2013 bone or cartilaginous vertebrae
\nBilateral symmetry \u2013 characteristic features on both sides
\nVentral chambered heart \u2013 \u201cclosed\u201d heart
\nClosed circulatory system \u2013 blood in heart or tubes; for example, veins and arteries
\nComplete digestive tract \u2013 from mouth to anus
\nCephalization \u2013 sensory\/nerve structures on \u201chead\u201d end<\/p>\n

5. Review Vertebrate Classification Handout.<\/p>\n

6. Define tetrapod, fish, agnathostome, and gnathostome.
\nTetrapod \u2013 four-limbed animal
\nFish – any of numerous cold-blooded aquatic vertebrates, characteristically having fins, gills, and a streamlined body and including specifically any of the Osteichthyes, having a bony skeleton and any of the class Chondrichthyes, having a cartilaginous skeleton and including the sharks, rays, and skates; any of various primitive aquatic vertebrates of Cyclostomata, lacking jaws and including the lampreys and hagfishes.
\nAgnathosotme \u2013 jawless vertebrates
\nGnathostome \u2013 jawed vertebrates<\/p>\n

7. Define and give an example of endothermic\/homeothermic and ectothermic\/poikilothermic animals.
\nEndothermic \u2013 generate own heat
\nHomeothermic \u2013 maintain steady temperature
\nExample \u2013 mammals, birds
\nEctothermic \u2013 heat from environment
\nPoikilothermic \u2013 temperature varies
\nExample \u2013 snakes, fish<\/p>\n

8. Examine the relative time periods of vertebrate classes; i.e. when did they originate\/dominate. Review Geologic Period Handout.<\/p>\n

9. What is an amniote and anamniote?
\nAmniote \u2013 an animal whose eggs contain an amnion, a membrane that surrounds the embryo and helps retain fluids and cushions embryo
\nAnamniote \u2013 an animal whose eggs lacking embryonic membranes or amnion<\/p>\n","protected":false},"excerpt":{"rendered":"

A. INTRODUCTION TO COMPARATIVE VERTEBRATE ANATOMY 1. Define comparative vertebrate anatomy, morphology, phylogeny, embryology. Anatomy \u2013 description and observation of structures Morphology \u2013 relating and interpreting structures Phylogeny \u2013 evolutionary history of a group or structure Embryology \u2013 study of … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":270,"featured_media":0,"parent":580,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"class_list":["post-597","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/users\/270"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/comments?post=597"}],"version-history":[{"count":0,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/597\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/580"}],"wp:attachment":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/media?parent=597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}