Plains Indian Studies - Smithsonian Institution Libraries

NUMBER 30 165
MNI MNI
FIGURE 25.—The extremes of the possible relationships between
minimum number of individuals (MNI) and total
fragment count (E) (a = relationship when each species is
represented by one bone type; b = relationship when each
species is represented by ten bone types).
creases, the lower limit "b" gets closer to the Xaxis.
In practice, bone element types are not
found in equal proportions, and the position of a
sample within the pie-shaped range is controlled
by what Holtzman (1979:78) has called the
"effective number of elements per individual"
(ENI). For instance, if one of the 10 element types
in the example actually turned up as 25% of the
samples, then the ENI would be 4 and the slope
of the relationship between MNI and E would
have a rise of about 1 in 4 instead of 1 in 10.
Therefore, any deviation from a straight line in
the relationship between MNI and E is due to a
change in the probability of recovering the most
common element type.
Some empirical evidence can be produced to
show that this is the case. If the MNI and E
values for all the bird samples in Parmalee's
report (1977:199, table 3) are plotted, the linear
configuration in Figure 26 results, indicating that
the effective number of individuals for the different
taxonomic groups in the samples does not
vary greatly. For other kinds of fauna the situation
is somewhat different. Computing the ENI
for bison in the three samples published by Gilbert
(1969:283, table 4) yields the following three
FIGURE 26.—Plot of the relationship between MNI and E
for a series of bird-bone samples from the Plains (Parmalee,
1977). The relationship is linear because the effective number
of elements per individual (ENI) for all the samples falls
within a very small range.
MN
oo
25 1X100)
FIGURE 27.—Relationship between MNI and E for a series
of caprine samples from three Near Eastern tells (X = points
for the site of Godin Tepe (A. Gilbert, 1979), which produce
the line A; 0 = points for the site of Beidha (Hecker, 1975),
which produce the line B; dots = points for the site of Tepe
Ganj Dareh (Hesse, 1978), which produce the line C; units
of E should be multiplied by 100).
values: Woodland, 6.9; Middle Missouri, 14.5;
Coalescent, 14.2. Adding values calculated from
Calabrese's (1972) study, 37.7 (his table 13), and
48 (his table 15), one can see evidence of what
would appear to be a highly variable relationship
between sites. In Figure 27 the relationship between
MNI and E for the caprine samples for
three Near Eastern tell sites are plotted. Each of
the distributions can be approximated by a
straight line. This suggests that the effective num-