Page 4 > of 9 ZOOM EXERCISE 2: Generation time matters Below is a life table with the bx column blank. Create two different life tables, each with different age specific bx values to see how this affects G, R. and r. NOTE: These are unusual life tables where only one age class ever breeds Table 1: make bx = 3 for 1 year olds, zero for all others (i.e., only 1 year olds ever breed) Table 2: make by = 12 for 3 year olds, zero for all others (i.e., only 3 year olds ever breed) ENTER the values of r, R. and G for each life table on the worksheet. on Out Note in this special case, generation time is identical to the sole age class that breeds. Note that these tables have the same R. values Finally, look at the ratio of the r values for the two tables. This will confirm the above conclusion that for the same Ro value, ris inversely proportional to G Enter the following ratios on the worksheet: r Table 1/r Table 2 1/2 G Table 1/G Table 2 G 2 X Sx bx Ix Ix*bx Ix*b*x 0 0 1000 0 1 0 1 500 0.5 0 0 0 2 250 0 0.25 0.125 125 0 0 0 4 0 0 0 0 R. = 0 G=##### r=#***## ElxbxX = 0 After you have completed the exercise, change both the survival values (3x) and births (bx) to to your heart's content to further get a sense how this changes population growth rate and generation time. (The only constraint is that Sx cannot increase from one age class to the next -- sorry, no reincarnation here!) Now move to Exercise 3 by clicking on the Exercise 3 tab below AutoSave OR OF A HP G ... Module 3 answer sheet 3 Home Insert Draw Page Layout Formulas Data Review View Tell me Share Comments Geneva 16 w v P A a Wraa Text General Insert v X LE v AYO ch Paste BIU - A = = - - Merge & Center $ -% Delete Format Conditional Format Cell Formatting as Table Styles Sort & Filter Sensitivity Find & Select Analyze Data L5 fx Y B C E F G H 1 J K Exercise 2. For each of the two life tables you have been asked to construct give r, Ro, and G (8 points): 11 1) Table 1 r = Table 1 Ro = Table 1 G = 12 13 2) Table 2 r = Table 2 R = Table 2 G= 14 15 3) Ratio of r Table 1/r Table 2 = 16 17 4) Ratio of G Table 1 / G Table 2 = 18 Exercise 3. For each change in birth rate indicate how the population is changing Sheet1 + Ready 185% Page 4 > of 9 ZOOM EXERCISE 2: Generation time matters Below is a life table with the bx column blank. Create two different life tables, each with different age specific bx values to see how this affects G, R. and r. NOTE: These are unusual life tables where only one age class ever breeds Table 1: make bx = 3 for 1 year olds, zero for all others (i.e., only 1 year olds ever breed) Table 2: make by = 12 for 3 year olds, zero for all others (i.e., only 3 year olds ever breed) ENTER the values of r, R. and G for each life table on the worksheet. on Out Note in this special case, generation time is identical to the sole age class that breeds. Note that these tables have the same R. values Finally, look at the ratio of the r values for the two tables. This will confirm the above conclusion that for the same Ro value, ris inversely proportional to G Enter the following ratios on the worksheet: r Table 1/r Table 2 1/2 G Table 1/G Table 2 G 2 X Sx bx Ix Ix*bx Ix*b*x 0 0 1000 0 1 0 1 500 0.5 0 0 0 2 250 0 0.25 0.125 125 0 0 0 4 0 0 0 0 R. = 0 G=##### r=#***## ElxbxX = 0 After you have completed the exercise, change both the survival values (3x) and births (bx) to to your heart's content to further get a sense how this changes population growth rate and generation time. (The only constraint is that Sx cannot increase from one age class to the next -- sorry, no reincarnation here!) Now move to Exercise 3 by clicking on the Exercise 3 tab below AutoSave OR OF A HP G ... Module 3 answer sheet 3 Home Insert Draw Page Layout Formulas Data Review View Tell me Share Comments Geneva 16 w v P A a Wraa Text General Insert v X LE v AYO ch Paste BIU - A = = - - Merge & Center $ -% Delete Format Conditional Format Cell Formatting as Table Styles Sort & Filter Sensitivity Find & Select Analyze Data L5 fx Y B C E F G H 1 J K Exercise 2. For each of the two life tables you have been asked to construct give r, Ro, and G (8 points): 11 1) Table 1 r = Table 1 Ro = Table 1 G = 12 13 2) Table 2 r = Table 2 R = Table 2 G= 14 15 3) Ratio of r Table 1/r Table 2 = 16 17 4) Ratio of G Table 1 / G Table 2 = 18 Exercise 3. For each change in birth rate indicate how the population is changing Sheet1 + Ready 185%