1986] Kane & Brunner — Neaphaenops tellkampfi 249 
the approximately 200 species of cave trechines in the eastern United 
States. Four morphological subspecies of N. tellkampfi have 
been described over its range in west central Kentucky. In the present 
study, electrophoretic data were collected on a total of 18 popula- 
tions to include all four subspecies. These data support the hypothe- 
sis that N. tellkampfi has been derived from a single isolation of a 
surface dwelling ancestor. The present distribution has apparently 
resulted from a northward movement of the troglobitic stock 
through subterranean routes. Morphological (i.e., subspecific) dif- 
ferentiation appears to be directly related to the presence of partial 
and/or complete geological barriers to dispersal in certain portions 
of the range. 
Comparison of genetic data on N. tellkampfi with those on other 
sympatric cave dwelling species suggests that level of gene flow and 
degree of genetic differentiation may be related to the degree of cave 
dependence of such species. Troglobites show lower levels of gene 
flow and greater genetic differentiation over their geographic ranges 
than do more facultative cave dwellers (e.g., troglophiles and tro- 
gloxenes) in which intermediate to high levels of gene flow have 
been reported. Ecological differences between species with similar 
degrees of cave dependence do not appear to produce differences in 
genetic patterns on a biogeographic scale. There is some evidence to 
suggest, however, that ecological differences between such species 
may affect genetic variability and genetic distance at the level of 
local populations. 
References 
Barr, T. C. 1968. Cave ecology and the evolution of troglobites. In: T. Dob- 
zhansky, M. K. Hecht and W. C. Steere (eds.) Evolutionary Biology, Plenum 
Press, New York pp. 35-102. 
Barr, T. C. 1979a. Revision of Appalachian Trechus (Coleoptera: Carabidae). 
Brimleyana 2: 29-75. 
Barr, T. C. 1979b. The taxonomy, distribution, and affinities of Neaphaenops 
with notes on associated species of Pseudanophthalmus (Coleoptera: Carabi- 
dae). American Museum Novitates: No. 2682 pp. 20. 
Barr, T. C. 1981. The cavernicolous carabid beetles of North America. Proceed- 
ings of the Eighth International Congress of Speleolology 1: 343-344. 
Barr, T. C. and R. A. Kuehne. 1971. Ecological studies in the Mammoth Cave 
ecosystem of Kentucky. II. The ecosystem. Annales de Speleolologie 26: 47-96. 
Caccone, A. 1985. Gene flow in cave arthropods: a qualitative and quantitative 
approach. Evolution 39: 1223-1235. 
