Biology Reference
In-Depth Information
FI
GURE 11.13
Plot of
the actual coverage versus
the stated coverage for the
250 individuals in the
simulated sample (step
function line). The diagonal
line is the line of identity.
0
20
40
60
80
100
Stated Coverage (%)
biology analyses that appear purely descriptive on the surface typically have some compar-
ative basis, and are consequently analytically oriented. For example, attempting to estimate
the sex ratio for neonatal skeletons using DNAmethods may begin as a descriptive endeavor,
but comparing the results to an expected sex ratio for perinatal deaths of near 1:1 and finding
a large departure warrants some explanation and further analysis. Alternatively, researchers
might begin with a hypothesis that a past population may have been practicing sex-biased
infanticide or differential neglect, as for example in
Faerman et al. (1998)
. Other studies
with a stronger comparative and thus analytical bent inclu
de Andrushko et al.'s (2010)
work on “trophy victims” (i.e., individuals who had body parts removed at or near death
during warfare) from prehistoric central California. This study, which demonstrated that
50% of trophy victims were young adults (18
e
25 years old) whereas only 17.6% of individ-
uals from the remainder of the skeletal sample died as young adults, would have had a much
stronger inferential basis if the entire age-at-death structure for trophy victims and for the
general skeletal sample had been estimated. Although it is beyond the level of this chapter,
the method of maximum likelihood can be used in a fairly straightforward manner to
develop tests of whether two or more age-at-death structures differ substantially, allowing
inferences into why or why not.
Because the demographic structure for populations is fundamentally related to so
many factors, estimation of sex ratios and/or age-at-death structure should be an integral
part of a complete skeletal biological analysis. For example,
DeWitte and Wood (2008)
