Biology 3315 Vertebrate Zoology Take-Home Essays – Exam 2 Fall 2008 General Information You can choose only one of the four papers listed below for your summary. At the end of this document are the questions associated with each of the papers. Your essay is due at the beginning of the exam on Monday. 1. Hillenius, W. J. and J. A. Ruben. 2004 The evolution of endothermy in terrestrial vertebrates. Who? When? Where? Physiological and Biochemical Zoology 77:1019-1042. 2. Farmer, C. 1997. Did lungs and the intercardiac shunt evolve to oxygenate the heart in vertebrates? Paleobiology 23:358-372. 3. Lips, K. R. 1998. Decline of a tropical montane amphibian fauna. Conservation Biology 12:106117. 4. Long, J. A. and M. S. Gordon. 2004. The greatest step in vertebrate history: A paleobiological review of the fish-tetrapod transition. Physiological and Biochemical Zoology 77: 700-719. Format Your essay must be typed. It is limited to the two pages and the pages must be stapled together. It must be double-spaced with a 12 point font and top, bottom and side margins that are at least 1”. Be sure to put your student identification number at the top of the page. DO NOT PUT YOUR NAME ON YOUR ESSAY! Points will be deducted if you do not follow this format explicitly. Evaluation Criteria Your essay should be directed toward imagined readers who are not familiar with the issue. The purpose of the essay is to develop a thesis statement about an issue and offer clear and logical support for your thesis statement. A good essay will enable the reader to clearly understand the issues being discussed, as well as your position on the issue. The grading criteria for the essay are (1) accuracy of content, (2) comprehensiveness and balance, and (3) clear sentence structure with good transitions. Accuracy of Content This refers to facts presented in the essay. Unless explicitly stated, you do not need to cite specific literature in essays. However, you must be sure that the information is factual, based on credible sources of information. Comprehensiveness and Balance Comprehensiveness refers to the thoroughness of coverage of the issues, presence and clarity of the thesis statement, and how convincingly you support your thesis statement. Essays must address the major issues related to the essay topic. That does not mean that an essay considers every possible facet of an issue. There is not enough space for minor or tangential issues. The writer must decide what is important and write succinctly about those issues. Balance has 2 components: 1) How much space (i.e. how many words) is allotted to each of the major issues that are covered in the body of the paper, and 2) How much space is allotted to the introduction, body and conclusion. Writers must judge the importance of each issue or concept and apportion space proportional to their importance. Writers must also make certain that the introduction, body, and conclusion are appropriate in length. The body should comprise the majority of the essay because that is where the issues are laid out and the supportive arguments developed. The arguments must convincingly support the thesis statement. The introduction must be brief, but provide an adequate introduction to the issues. Lastly, the conclusion is typically the shortest section. A good conclusion should provide a terse and unambiguous close to the essay, which is easier said than done. Clear Sentence Structure with Good Transitions Because essays are short in length, each sentence must be carefully arranged and edited for maximum clarity. This will not happen on your first attempt. It takes much editing to produce a succinct and clear essay. Concepts in essays should flow smoothly from one idea to the next. Therefore, good transition sentences are essential. Keep in mind that smooth transitions result more from clear organization than writing prowess. If an essay is well thought out, the ideas will naturally follow each other. Nature of the “Questions” For each of the readings, I have listed the major points that need to be addressed. These points should not be considered as an “outline” for your essay, but rather as a check list of key issues that need to be addressed. 1. Hillenius, W. J. and J. A. Ruben. The evolution of endothermy in terrestrial vertebrates. Who? When? Where? Physiological and Biochemical Zoology 77:1019-1042. After reading the article, compose a summary that addresses the following questions. When appropriate, incorporate material from your lecture notes or the Pough et al. text to support your answer. Hillenius and Rubin argue that the earliest evidence for endothermy in the mammalian lineage appeared in the Late Permian period while a similar type of evidence appeared in birds during the Cretaceous. Your essay should clearly explain what this evidence is and why the authors consider it such strong evidence of the origins of true endothermy in these two lines of terrestrial vertebrates. 2. Farmer, C. 1997. Did lungs and the intercardiac shunt evolve to oxygenate the heart in vertebrates? Paleobiology 23:358-372. After reading the article, compose a summary that addresses the following issues. When appropriate, incorporate material from your lecture notes or the Pough et al. text to support your answer. The traditional view of the evolution of the lung links its respiratory function to aquatic habitats that were either anoxic or very low in dissolved oxygen. Farmer discounts this argument and proposes an alternative pathway to lungs. Briefly summarize the evidence she presents countering the “anoxic environment” hypothesis, then explain her alternative hypothesis. 3. Lips, K. R. 1998. Decline of a tropical montane amphibian fauna. Conservation Biology 12:106-117. After reading the article, compose a summary that addresses the following questions. When appropriate, incorporate material from your lecture notes or the Pough et al. text to support your answer. Karen Lips was one of the first researchers to clearly document wide-spread amphibian decline in a single area. In her article, she uses her data to narrow the range of possible factors causing the declines to either biotic pathogens/environmental contaminants or a combination of these factors plus climate change. How does she arrive at these conclusions and do you find here arguments convincing? 4. Long, J. A. and M. S. Gordon. 2004. The greatest step in vertebrate history: A paleobiological review of the fish-tetrapod transition. Physiological and Biochemical Zoology 77: 700-719. After reading the article, compose a summary that addresses the following issues. When appropriate, incorporate material from your lecture notes or the Pough et al. text to support your answer. Long and Gordon define five groups they consider important in understanding the evolutionary transition from fish to tetrapod. What were the major anatomical changes associated with each of these five groups? What is heterochrony and what role does it play in Long and Gordon’s explanation?