34 
Psyche 
March 
that the forests at the three localities, or the ant faunas in 
them, had been seriously disturbed by man. All three locali- 
ties contained rich endemic Papuan faunas, with virtually 
no infi tration of introduced species. 
Subjective impressions of the relative abundance of sev- 
eral of the dominant ant species are presented in Table 1. In 
each of the three localities, all of the major microgeographic 
areal divisions were studied. Each locality was visited at 
least twice during the author’s two month stay in the Lae 
area, and a minimum of four days devoted to intensive col- 
lecting. Under these conditions, only the commonest species 
could be compared, but differences in local abundance of 
these were so striking that it seems safe to predict that 
similar patchy distributions are exhibited by other, less dom- 
inant members of the fauna. 
Discussion: The Evolutionary Implications 
of Patchiness 
In any appraisal of comparative ecology, the New Guinea 
ant fauna is to be characterized first of all by the exceptional 
richness of its species and the great size of its biomass. The 
present study has shown that in addition to sheer size, an 
additional factor adds greatly to the total faunal complexity. 
This is the discordant patchy distribution of individual 
species. The fractioning of species into small subpopulations 
that are partially isolated from one another probably results 
in relatively high rates of evolution, whether through ran- 
dom drift or differential selective pressures or both (see for 
instance Kimura, 1955, and Ford, 1955). Moreover, as a 
result of discordant patchiness, no two localities harbor 
exactly the same fauna. Considering that several hundreds 
of species are thus involved, it is clear that the spatio- 
temporal structure of the entire New Guinea fauna must 
present the appearance of a great kaleidoscope. The effects 
of such a structure on the evolution of individual species of 
Explanation of Plate 5 
Plate 5. Floor of primary open-aspect rain forest near the lower 
Busu River. The undergrowth at this spot is made up preponderantly of 
an unidentified speces of Selaginella. 
