Worksheet 5 â Competition
This worksheet is designed to help you:
Understand the differences between intraspecific and interspecific competition.
Determine factors that may drive competition in nature.
Answer/address all of the following questions. In all cases, we require that your work be typed and that you make computer printouts of spreadsheets, graphics, or statistical output.
Provide 2 examples of intraspecific competition and 2 examples of interspecific competition. Cite your sources (16pts). Explain which scenario has more intense competition.
2. Produce a table showing the average number of beans collected by each individual during each foraging experiment (20pts).
An example raw data table is provided below â you are required to make a summary table from this information (hint: do not include raw data, only summary values, in a summary table).
3. Produce a bar graph (or bar graphs) reporting the experiment averages with appropriate error bars for each foraging experiment (16pts).
4. Provide null and alternative hypotheses for each foraging experimentâa total of 5 sets of hypothesis. (6 pts)
(hint: the 5 hypotheses will be (1) intraspecific competition between small beaked birds (experiment A), 2) Intraspecific Competition between large beaked birds (experiment B), (3) interspecific competition for small beans (experiment C), (4) Interspecific competition for large beans (Experiment D), 5) high vs. low density intraspecific competition (average A vs. average E).
5. Perform appropriate statistical tests for each hypothesis (12pts).
(hint: you are attempting to find out if there is a significant differences between two populations â for (i) and (ii) the statistical test will be paired and for (iii) the statistical test will be unpaired)
6. Discuss the results of each statistical test, and explain why you observed these patterns (15pts).
7. Explain how competitionâboth intraspecific and interspecificâdrove the evolution of Darwinâs finches (below) to develop specialized beak shapes? What do the different species compete for, and why are differences in morphology (e.g. bill shape and size) important? (15 pts)
