LECTURE 08 POPULATION GROWTH AND REGULATION 2
For this lecture, bring
PRINTOUT of this and last Tuesday’s lecture outline
** PG. 221 FROM LAB MANUAL **
Completed Problem Set 1 (problems 1-7); Problem Set 2 (problem 2)
Learn what bolded words below mean by looking at relevant figures; study Table 11.1
MAJOR CONCEPTS
1. The age structure of a population reflects its history of survival, reproduction, and
potential for future growth.
2. How fast a population grows depends on its age structure.
3. A life table summarizes age-specific schedules of survival and fecundity.
4. A life table can be used to estimate net reproductive rate (Ro), geometric rate of
increase (), generation time (T), and per capita rate of increase (r).
5. A survivorship curve summarizes the pattern of survival over time in a population.
I. Age structure: proportion of individuals in each age class. 227-9
Influences population growth rate.
Stable and growing populations have very different shapes. 11.6
Shape of age structure shifts when populations change birth/death rates 11.7
II. Life Table analysis for differential equations 229-231
Includes complexity of age-specific survival and fecundity Table 11.1, Table 11.4
Summarizes demographic information by age class
Fecundity Probability of survival
III. Life table: provides calculations of: 234-235 Table 11.7
T = mean generation time
Ro = net reproductive rate (per lifetime); when Ro = 1, population is stable
r = ln Ro/T
 = er
Doubling time
t2 = ln2 / ln 
t2 = ln2 / r
ex = life expectancy
IV. Cohort vs. static life tables (advantages and disadvantages) 231-234
11.8, 11.9, Table 11.6
Cohort: all individuals born at same time
Shapes of survivorship curves (Type I, II, and III) 11.10
V. Use life table to project future population size and age structure Tables 11.2, 11.3
Get stable age distribution (SAD) with time, even with population growing
Each age class grows (or declines) at same rate ()
 fluctuates, then becomes constant with time
Assumes birth and death rates are constant