An adaptive model for predicting !Kung reproductive performance : a stochastic dynamic programming approach
A stochastic dynamic programming model is presented that supports and extends work on the reproductive performance of the !Kung Bushmen (Lee 1972), (Blurton Jones et al. 1978), (Blurton Jones 1986) proposing that !Kung women and their reproductive systems may be maximizing reproductive success. T...
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Language: | English |
Published: |
2009
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Online Access: | http://hdl.handle.net/2429/6087 |
Summary: | A stochastic dynamic programming model is presented that supports and extends work
on the reproductive performance of the !Kung Bushmen (Lee 1972), (Blurton Jones et al.
1978), (Blurton Jones 1986) proposing that !Kung women and their reproductive systems
may be maximizing reproductive success. The stochastic dynamic programming approach
allows the construction of a "whole-life" model where the physical/environmental constraints
along with the uncertainty about future events !Kung women face when making
reproductive choices can be explicitly built in. The model makes quantitative predictions
for the optimal reproductive strategy assuming !Kung women are maximizing expected
lifetime reproduction (ELR) given the physical parameters of !Kung life.
The model relies on data gathered from the works cited above and some considerations
from simple probability theory. The model predictions for optimal birth spacing
match the !Kung reproductive data very well and support earlier findings (Blurton
Jones and Sibly 1978), (Blurton Jones 1986). The utility of the dynamic modeling
approach is illustrated when the effects of varying certain model parameters are investigated.
By including the effect of the mother's mortality which was not included in the
Blurton Jones and Sibly (1978) analysis, the model allows for further exploration of
the application of an adaptive approach to human reproductive performance. By adding
some considerations about the risks of childbirth for the mother the model not only predicts
optimal birth spacing which is site specific but also predicts the optimal time for
a woman to begin and cease having children. These predictions coincide with menarche
and menopause and shed light on their possible adaptive value. |
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