1. Human Life Tables and Survivorship Curves

2. What are life tables?
A life table contains age-specific survival and mortality rates in a population. It also contains fecundity and age distribution information.
Life tables come in 2 varieties:
Cohort life table: Follows a group of individuals born at the same time.
Static life table: Constructed by recording the age at death of a large number of individuals. This is what we’ll be making.

3. What are survivorship curves?
Graphs made from life tables that show the survivorship (log # of survivors) in each age group.
There are 3 basic types…

4. Type I (convex) Many mammals show this type of survivorship.
Most individuals will live a long time and die in the largest age groups.

5. Type II (straight/linear)
Many song birds and seeds in a soil seed bank show this type of survivorship.
There is a constant rate of survival, for example, 10% survive each age group.

6. Type III (concave)
Many invertebrates and marine fish show this type of survivorship.
Most individuals die as juveniles.

7. Purposes, predictions, and hypotheses
Get practice using life tables.
Test some predictions about human survivorship.

8. Why might men live longer than women?

9. Risks associated with childbirth

10. Why might women live longer than men?

11. Risky behavior

12. Smoking

13. Homicide and suicide

14. Alcohol

15. Toxic effects of testosterone

16. War

17. Why has human life expectancy increased over the last several decades?

18. Improvements in medicine, nutrition, and sanitation

19. What are some hypotheses we can form based on the previous information and predictions?

20. HYPOTHESES:
HO: The life expectancy of women is the same as for men or less than that of men.
HA: Women have a greater life expectancy than men.
HO: Men do not have a greater life expectancy during child bearing years.
HA: Men have a greater life expectancy than women during child bearing years.
HO: Human life expectancy has not increased over the period of time during which people were buried in our study area cemeteries.
HA: Human life expectancy has increased over this time period

21. Methods Work in pairs (but preferably no more than seven groups)
Choose a row of headstones, respectfully walk down the row, and record the data listed on the data sheet (sex, YEAR of death, YEAR of birth).
Choose headstones by simply recording the next one you come to. Include infants.
Record data for 50 males and 50 females.
Be careful of incorrect data. There have been records of people living 150+ years or less than 0 years.
Do not overlap with another group.

22. Put your data in an Excel file in the exact format as your data sheet and it to your TA as an attachment.
Both team members lose participation points if this is not done by 7:00 pm Tuesday night.