NAME: DATE: PERIOD: Population Distribution & Survivorship— HTPA Cemetery
Background: Most individuals do not reach the maximum life span of their species. The ratio of age at death to the surviving portion of a population is a function of the species (and for humans – their cultural and socio-economic conditions). A survivorship curve shows the probability that an individual of a particular species, age and gender will survive to a certain age. Humans follow the Type I survivorship curve.
PRE-LAB: 1. Define survivorship.
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2. What does a survivorship curve show? ______
3. Describe the three types of survivorship curves. Type I ______Type II ______Type III ______
Purpose: Students will explore and calculate common demographic data in a cemetery to infer patterns and trends in a population.
PROCEDURE: Tables 1 and 2 1. Collect and record the data from the Harbor Teacher Preparation Academy Cemetery. a. Record all individuals born before 1880 in Table 1. Record their name, sex, and dates lived. b. Record all individuals born 1880 or after in Table 2. Record their name, sex, and dates lived.
2. Calculate the age at death for each individual. Record on each table.
Tables 3 and 4 3. DEATHS Using Tables 1 and 2, count the number of individuals who died in each 5-year age group (ex. If 4 people died at an age between 15 and 19, enter 4). a. For pre-1880 deaths, record in Table 3. b. Repeat for the post-1880 deaths. Record in Table 4.
4. SURVIVORS Determine survivors in each age group (to start, pre-1880 age interval 0-4 will be the total # of males/females from Table 1 MINUS the # of deaths for that interval). EXAMPLE DATA: For the remaining age intervals, subtract the # of deaths from that age Pre-1880 total number of individuals =25 M, 25 F interval from the previous age group’s # of survivors. Pre-1880 Survivorship: a. For pre-1880 survivors, record in Table 3. Age 0-4 Deaths = 1 male, 1 female Age 0-4 Male Survivors =24 b. Repeat for the post-1880 survivors. Record in Table 4. Age 0-4 Female Survivors = 24 Age 0-4 Male Survivorship = 24/25= 96% Age 0-4 Female Survivorship = 24/25 = 96% 5. SURVIVORSHIPCalculate survivorship as a percentage (# of survivors/total individuals) a. For pre-1880 survivorship, record in Table 3, for males and females. b. Repeat for the post-1880 group. Record in Table 4, for males and females. An example is below.
Prediction: What do you expect to see when comparing the four survivorship curves?
______Graph 6. Plot your four survivorship data sets (Tables 3 and 4) by age group on one graph. Use different colors for each data set. Don’t forget to title your graph, label both axes, and fill in the legend showing your color choices. An example is given to the right. 7. Connect the data points to create pre- and post-1880 survivorship curves for males and females.
ANALYSIS:
1. Overall, how did the pre-1880 and post-1880 survivorship curves differ? Why? ______2. Overall, how did the male and female survivorship curves differ? Why? ______3. Provide some possible biological/historical/societal causes for any differences you see in the survivorship curves. For example, was there a major disease at the time? War? Change in attitude towards family sizes? ______4. What is your interpretation of infant and child mortality (ages 0-19) for males and females in each time period? List and describe all factors that might account for any differences you see. Pre-1880 Post-1880 Males Females Factors that might account for differences
5. What is your interpretation of mortality for reproductive ages (age 20-39) for males and females in each time period? List and describe all factors that might account for any differences. (Note: many men who died during WWI and WWII were not returned to the United States). Pre-1880 Post-1880 Males Females Factors that might account for differences
6. What is your interpretation of mortality for adults ages 80 and above for males and females in each time period? List and describe all factors that might account for any differences you see. Pre-1880 Post-1880 Males Females Factors that might account for differences
7. What shifts in survivorship curves would you expect to see if environmental problems worsen and pollution-related diseases increase? Explain why. ______8. What shifts in survivorship curves would you expect to see if cutbacks to social services such as prenatal and infant care are enacted? Explain why. ______9. How would the survivorship curves of a developing country compare to those of a developed country? ______10. How could survivorship curves be used to make judgments about environmental and health conditions in a country? ______11. If you collected data for 100 more years, what do you think the survivorship curves would show? ______
Summary: Revisit the PURPOSE of the activity. Did you accomplish this? Explain.
______Data Tables: Harbor Teacher Preparation Academy
Cemetery
Table 1: Individuals born before 1880 Name on Tombstone Sex Dates Lived Age at Death
Table 2: Individuals born 1880 or after Name on Tombstone Sex Dates Lived Age at Death
Table 3: Deaths, Pre 1880 (From Table 1) Age Total How # of Male % How Many # of Female % Category Deaths Many Survivors Survivorship Female? Survivors Survivorship Male? (total # of Males (total # of Female males/females (# of males/females (# of from Table 1 survivors/total from Table 1 survivors/total MINUS the # individuals) MINUS the # individuals) of deaths for of deaths for that interval) that interval) 0-4 5-9
Table 4: Deaths, Post 1880 (From Table 2) Age Total How # of Male % How Many # of Female % Category Deaths Many Survivors Survivorship Female? Survivors Survivorship Male? (total # of Males (total # of Female males/females (# of males/females (# of from Table 1 survivors/total from Table 1 survivors/total MINUS the # individuals) MINUS the # individuals) of deaths for of deaths for that interval) that interval) 0-4 5-9 If there were 19 survivors to start with and one died, the % survivorship is 18/19 and then multiplied by 100 = 94.7%