1958 
Wilson — Ant Species in New Guinea 
37 
(Fuggles-Couchman, unpublished). But this does not 
happen in the neighboring forests of the Mbulu District, 
where the fruit-eating barbets are not represented at 
all.” 
Additional examples from other animal groups and other 
parts of the tropics (as well as the temperate zones) could 
be cited to show that patchiness is a widespread phenomenon, 
on both a very local (microgeographic) and broader (geo- 
graphic) scale. To all such cases Richards’ conditions must 
be applied, i.e., it must be asked whether patchiness has not 
arisen exclusively as a result of man-made disturbances. But 
patchiness as a result of natural disturbances, such as tree 
falls and stream erosion, is a good possibility also, and 
should be considered in the future. In the author’s present 
opinion, much of the patchiness observed in New Guinea 
ant populations has actually arisen through natural dis- 
turbances, since enclaves of second-growth vegetation are 
a normal feature of remote, undisturbed forest. This argu- 
ment has been taken up in somewhat more detail elsewhere 
(Wilson, 1959). 
Summary 
The population structure of individual Papuan ant species 
is shown to be generally irregular. Patchiness exists at both 
a local, clearly ecological level, and a broader, “geographic” 
level not easily correlated with environmental influences. The 
combined irregularities in the distributions of multiple 
species result in distinct shifts of faunal composition and 
relative abundance over distances of only a few kilometers 
even in relatively continuous, homogeneous rain forest. The 
theoretical implications of discordant patchiness with respect 
to rapid evolution are discussed. 
Literature Cited 
Aubreville, A. 
1938. La foret coloniale : les forets de l’Afrique occidentale frangaise. 
Ann. Acad. Sci. Colon., Paris, 9: 1-245. 
Ford, E. B. 
1955. Rapid evolution and the conditions which make it possible. 
Symp. Quant. Biol. (Cold Spring Harbor), 20: 230-238. 
