Assignment # 2 Based on the paper by Creighton, J. C, ENY 3005 25 points *PLEASE NOTE THAT I WILL NOT ACCEPT THIS ASSIGNMENT LATE. WE WILL BE GOING OVER THE ANSWERS IN CLASS. JUST IN CASE YOU GET A COLD OR THE FLU, PLEASE COMPLETE THIS ASSIGNMENT IN ADVANCE. THAT’S YOUR SAFEST BET!* Due Wednesday, Feb 22 nd Please insert your response after each question and email me your assignment as an attachment by 10pm on Feb 22 nd , 2012. The filename of your attachment should include your name and “Assignment 2” in the following form: Smith_Assignment 2 (2 points off if not in this form). The subject line of the email should be the same or something similar. Please complete assignment in Microsoft Word. Please bring an extra copy to class; we will be going over it. Population density, body size, and phenotypic plasticity of brood size in a burying beetle. Behavioral Ecology Nicrophorus spp. www.alexanderwild.com Our goal is to help you better understand how scientific papers are structured, find critical points in the manuscript, and learn how to interpret results. As a class, we will discuss this paper on Thursday, February 23 rd . Before class, you are asked to carefully read this
Transcript
Assignment # 2 Based on the paper byCreighton, J. C,
ENY 300525 points
*PLEASE NOTE THAT I WILL NOT ACCEPT THIS ASSIGNMENT LATE. WE WILL BE GOING OVER THE ANSWERS IN CLASS. JUST IN CASE YOU GET A COLD OR THE FLU, PLEASE COMPLETE THIS ASSIGNMENT IN ADVANCE. THAT’S YOUR SAFEST BET!*
Due Wednesday, Feb 22nd
Please insert your response after each question and email me your assignment as an attachment by 10pm on Feb 22nd , 2012. The filename of your attachment should include your name and “Assignment 2” in the following form: Smith_Assignment 2 (2 points off if not in this form). The subject line of the email should be the same or something similar. Please complete assignment in Microsoft Word. Please bring an extra copy to class; we will be going over it.
Population density, body size, and phenotypic plasticity of brood size in a burying beetle. Behavioral Ecology
Nicrophorus spp. www.alexanderwild.com
Our goal is to help you better understand how scientific papers are structured, find critical points in the manuscript, and learn how to interpret results. As a class, we will discuss this paper on Thursday, February 23rd . Before class, you are asked to carefully read this scientific paper and complete this assignment. Answers should be in your own words, not quoted from the paper.
This paper, as do most scientific papers, starts out with an abstract. After the abstract the introduction section of the paper begins.
Note the ‘supplementary material’ section: this will provide a few definitions and the rationale that aims to aid in explaining the general rationale behind the study. For questions, email [email protected]
Creighton, J. C. (2005) Population density, body size, and phenotypic plasticity of brood size in a burying beetle. Behavioral Ecology 16: 1031-1036
INTRODUCTION
1) Provide an outline for the introduction of this paper. Include the main point of each of the paragraphs of the introduction (4 pts total).
2) Give a brief description of the background of the study. Identify the gap in knowledge that this author aims to address. Why is this gap in knowledge important(3pts)?
3) What is the main hypothesis that the author presents in this paper? What are the three predictions the author seeks to test based on this hypothesis?Is the hypothesis falsifiable, directional and testable? (3pts).
4) What are two mechanisms by which a female can adjust her brood size? (1pt)
METHODS
5) What are the three main approaches the author used to test his predictions?(Two or three sentences summarizes each) (2pts)
RESULTS & DISCUSSION
6) Explain and discuss the results for each of the experiments (8 pts). Include:a. Discussion of the information in each of the figuresb. Whether the results of the study refute or support findings from other
organisms. i.e. that female clutch size can be plastic.
OPINION
7) What do you find most interesting about this paper? (3pts)
Supplementary Material
Phenotype - These are the observable characteristics or traits of an organism that are expressed. In contrast to genotype, which are the genes of an organism that may or may not be expressed.
Maternal effects - This is when the phenotype of an organism is at least partially determined by non-genetic influences of the mother. In this case a mother may affect the size of offspring by adjusting the number of offspring in a brood, this is an example of a maternal effect on offspring size.
Phenotypic plasticity- The ability to produce different phenotypes by a single genotype. For example, you may get a tan in the sun. Your skin color has changed, but you have the same genotype.
Adaptive phenotypic plasticity - a phenotypically-plastic change that is adaptive (results in increased fitness).
Rationale
Is female brood size an adaptively plastic trait? In other words, do females adjust the number of offspring they produce to increase the fitness of these offspring? In this case, if females produced fewer offspring then these offspring will be larger. Thus by adjusting brood size mothers can influence the size of their offspring (maternal effects). The author provides evidence from previous studies that at high population densities, only larger beetles get to breed. At low population densities both large and small beetles get to breed. If mothers were adjusting brood size adaptively, what would you expect at low and high population densities?
