1988] 
Hagen, Smith, & Rissing — Two desert ants 
197 
Table 2. Relatedness and F-statistics for V. pergandei and A. versicolor 
foundress associations. The S.E. is standard error of relatedness, r, based on 
jacknifing over N groups of foundresses or nestmates. The mean r for V. pergandei 
foundresses is calculated from the weighted mean F st and F it across loci. 
LOCUS 
r 
S.E. 
Fst 
Fu 
N 
V. 
pergandei 
Est-1 
0.043 
0.106 
0.0208 
-0.0308 
24 
Est-2 
-0.009 
0.093 
-0.0049 
0.0527 
31 
Mdh-l 
-0.117 
0.043 
-0.0554 
-0.0561 
31 
Pgm 
0.174 
0.158 
0.1107 
0.2685 
31 
Mean 
0.033 
0.0176 
0.0638 
A. 
versicolor 
Pgm 
-0.125 
0.028 
-0.0632 
0.0077 
26 
Discussion 
Foundress associations of V. pergandei and A. versicolor are not 
composed of close kin. Veromessor pergandei and A. versicolor 
foundresses do not deviate from random assortment of genotypes, 
precluding the operation of kin selection (Wilson 1977, 1983; Wade 
1985). Similar random association of genotypes occurs in polygy- 
nous Solenopsis invicta colonies (Ross and Fletcher 1985), which 
are likely founded cooperatively. No other cooperatively founding 
ant species have demonstrated behavioral evidence of preferential 
association among relatives (Rissing and Pollock 1988), suggesting 
that results from the three species now studied electrophoretically 
are likely to be general. The genetic basis for cooperative behavior 
among co-founding queens, therefore, cannot be described as a 
direct consequence of kin selection. 
Genetic diversity of many Hymenoptera is lower than found in 
other insect orders owing either to haplo-diploid sex determination 
(increasing selective pressure on deleterious alleles exposed in 
haploid males or decreasing effective population size) or behavioral/ 
environmental peculiarities characteristic of many species, espe- 
cially social ones (social structure lowering effective population size 
and providing a nest structure that buffers environmental variabil- 
ity) (reviewed in Graur 1985, Sheppard and Heydon 1986). The 
decreased variability of A. versicolor relative to V. pergandei may 
reflect differences in the mating systems of the two: while all A. 
versicolor colonies in an area release alates on a single day (Wheeler 
1917, Rissing et al. 1986), V. pergandei colonies release alates over a 
three month period with little coordination of reproduction among 
