I wrote a simple prehistoric carrying capacity model in Java over the
summer. The primary interest of the study was to explore how the
variation in assumptions might influence the population dynamics that
were modelled. The parameters input by the user included initial age
distribution of the population, the model of food productivity per
person as a function of the weather and other processes (but not in
the detail seen in Zubrow (1975)), a model of mortality by year
class, children produced per woman, and assumptions about internal
exchange of resources. The simulation used a time step of one month,
ran for a user-defined period, and reported the age distribution of
the population yearly in a form suitable as input to a spreadsheet
for analysis or graphing. The age distribution was input as an
initial male and female population count for each age between 0 and
80. The mortality model incorporated background mortality based on
Coale and Demeny’s Western Region life tables (1983), following McCaa
(1998) and additional mortality due to malnutrition (Collins, Myatt
et al. 1998 and other sources). It is easily modifiable if the user
programs in Java, and I am willing to work with users to add
appropriate changes. It uses forward Euler integration, and so is
vulnerable to instability, but I can reprogram it using Crank-
Nicholson or backward Euler if that turns out to be a concern.
It's available from my teaching web site at <http://
osiris.sunderland.ac.uk/~cs0her/pub/Wessex.pdf> and <http://
osiris.sunderland.ac.uk/~cs0her/pub/Wessex.zip>.
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"The data (or the marks when teaching) are sacrosanct--they tell us
what actually happened." Harry Erwin, PhD
http://osiris.sunderland.ac.uk/~cs0her
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