Please place your name in the upper-right corner.

  1. Yesterday in lab you learned about some R basics. Please:
    1.1. Name two data types in R.
    1.2. Name the two types of data structures that are 2-dimensional and note which has homogeneous data types and which heterogeneous.
    1.3. Please write, by hand, how you would create a function for finding the hypotenuse of a right triangle if you know the lengths of two sides?






  2. What is the difference between endogenous and exogenous dynamics? Please give an ecological example of each.





  3. We represent population change as \(\Delta N = N_{t} - N_{t-1}\). The units for \(N\) are \([\text{individuals}]/[\text{area}]\) or, alternatively written, \([\text{individuals}][\text{area}]^{-1}\). Remember when you add or subtract units, they remain unchanged; i.e., the right-hand side equation in the first sentence has units of \([\text{individuals}][\text{area}]^{-1} - [\text{individuals}][\text{area}]^{-1} = [\text{individuals}][\text{area}]^{-1}\). When you multiply units they square; e.g., the area of a rectangle has units of length squared because it is a side (units in length) times another side (units in length). With division, like speed (i.e., velocity), it’s distance units of distance divided by time. Notice, too, that the units balance between the left- and right-hand sides balance.
    With all of that, the book reads that populations change \(\Delta N = BN_{t-1} - DN_{t-1}\). \(B\) is the per-capita birth rate and \(D\) is the per-capita death rate. Please justify why \(B\) and \(D\) are called “per-capita” by finding the units of \(B\) and \(D\) while remembering that the left- and right-hand sides of the equation must balance.











  4. If in year 2022, female white-footed mouse (Peromyscus leucopus) density is 0.1 / ha here in Maine forests. Lifespans are around 1 year for this species. If females produce 2 female pups per year, how many female mice would we expect after 7 years? (No need to recall an equation, just arithmetically trudge through.)

    (So cute)













  5. If in year 2022, female white-footed mouse (Peromyscus leocopus) density is \(N_{2022}\) / ha here in Maine forests. Lifespans are around 1 year for this species. If females produce \(\lambda\) female pups per year, how many female mice would we expect after \(t\) years? (This is the same question as above, but with variable names instead of numbers.)