1. Populations Review & Human Demography

2. Populations Review…

3. Populations Review

4. Populations Review

5. Limiting Factors

6. Let’s debrief/discussion the Population Activity from last week…

7. Human Demography

8. The study of age structure and growth rate of a population
Demography
The study of age structure and growth rate of a population

9. Life Table Used by population biologists to:
Determine patterns of survival
Study demographics within a population
2 kinds of tables…

10. Cohort Life Table Cohort = individuals that are the same age
Follow one cohort from birth to death

11. Cohort Life Table

12. Information Derived from Cohorts
(1) Net reproductive rate
Average number of offspring produced by an individual in it’s lifetime

13. Information Derived from Cohorts
(2) Generation time
The average age at which an individual gives birth to its offspring

14. Information Derived from Cohorts
(3) Per capita rate of increase
The rate at which the population is increasing or decreasing

15. Static Life Table
Record the age at death for individuals who died in a given time period
Provides a “snapshot” of survival

16. Static Life Table

17. Summarize pattern of survival in population
Survivorship Curves
Summarize pattern of survival in population
Type 1 Curve
High survivorship of young and middle age with low survivorship in old age
E.g. humans

18. Summarize pattern of survival in population
Survivorship Curves
Summarize pattern of survival in population
Type II Curve
Same survivorship rate throughout life
E.g. birds, squirrels

19. Summarize pattern of survival in population
Survivorship Curves
Summarize pattern of survival in population
Type III Curve
Low survivorship of young and middle age with high survivorship in old age
E.g. fish, mollusks

20. Reproductive Strategies
Based on evolutionary history and stability of environment
Goal: Optimize population size and success
Two strategies:
r-selection
K-selection
Draw a T-chart below this content!

24. Video Link – Putting it all together
7-minute video

25. Lab Introduction
Life styles have changes dramatically over the last 150+ years in the US
These changes are reflected in age at death
Examining cemetery data allows us to study the changes in human populations

26. Lab Overview
Cemetery data collection to examine human population trends
Collect data from assigned digital cemetery
Compile data with others for a given time period
Create life tables and survivorship curves

27. Link for Overview

28. Discussion Points
Why would we use a static (snap-shot) life table approach instead of a cohort life table approach to examine trends inhuman data?
What factors do you think have contributed to changes in human demographic patterns (including life span) over the last 200 years?