Volterra 1926

Discussion

Biology 570

  1. Where is the theoretical model in this paper? How does Volterra describe it? How would you write an equation for the rates of change of population size of the two species when they are alone, based on what he says?

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  2. What is the main prediction about the growth of the two species together? In what way does this prediction relate to the egg-shape of the lines in Figure 1? Look at Huffaker's Figure 18 of the dynamics of predator and prey mites. Does Huffaker's result match the expectations from Volterra's theory? In what way is it similar or different?

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  3. What does Volterra's law (3) on p 559 (284) predict if pesticides applied to a field specifically killed predatory insects, and did not harm their prey?

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  4. What is the prediction if prey populations suddenly had higher natural growth rates?
  5. Volterra claims on p 559 (284) that his theory predicts what happened to sharks (selachians) and their prey in the Adriatic Sea (between Italy and the former Yugoslavia) between 1910 and 1925. In what way were the predictions consistent with observation? Is it different from your answers to questions 3 and 4?
  6. What does Volterra predict about the dyanamics of a 3-species system living on an island (p 560 [285]), and how does that prediction differ from his 2-species case?