Lectures 20,21, 22
The colors indicate small changes made each day. Don't print all the new versions,
just check through to find the colored changes.
5:15 Nov 24, 2009
VERSION B 9:50 November 20, 2009
Version D. 3PM, December 1, 2009
Reading, 54.3 pages 1173-1174
1) Single-species population growth.
b) Population Size, N
Population size at time, N
d) Absolute Numbers of:
ii) Deaths, D
iii) Immigrants, I, disperse in from elsewhere.
iv) Emigrants, E, leave, disperse away.
Per Capita numbers of:
iii) Immigrants and emigrants with same logic, divide absolute number per unit
time by number in the population, N.
Area occupied by the population, A
g) Density, N/A.
h) Generations or time periods, the time t between censuses.
Absolute change, or difference, in N between generations, N
Exponential, density independent population growth .
k) Doubling time.
Density dependent, limited, regulated population growth.
Malthus was the first to convince the intellectual world that all organisms have the
potential for exponential population growth. He took this profound insight one step
farther with the additional insight that while human population tends to grow
exponentially in good times, food resources are limited by agricultural area so they can
grow only arithmetically. He said, (his “geometrical” means our “exponential”).
“Population when unchecked increases in a geometrical ratio
Subsistence increases only in an arithmetical ratio A slight acquaintance
with numbers will shew the immensity of the first power in comparison of
the second ”