D : 1 
alhousie Springs hydrobiids Ё 
D. globosa 
Ca 
Cal (D24) 
A 
Ca 
Cd 
Cc 
Db 
D. harrisi 
based on complete linkage clustering of Nei's unbiased (Nei, 
d into spring groups. D. globosa Cala (D24) and D. harrisi 
as suggested by inspection of their genetic frequencies. 
Fi u: 
Sure 24. Phenogram showing relationships of Dalhousia 
1978) genetic distances between samples poole 
НІ and H3 samples have been treated separately, 
dee separation, particularly in D. harrisi. Clear exceptions to this are the high degree of 
ge nce of the Cala (D24) sample from the remainder of D. globosa and the low divergence 
Sprin n the F spring group and the geographically distant H3 spring in D. harrisi. In D. harrisi, 
x SE В is quite basal when UPGMA linkage is used for the clustering (Fig. 23). If, however, 
Pheno nogram is based on “complete” linkages, the pooled sample for B is the sister to A (Fig. 24). 
grams (e.g. Fig. 23) reveal a number of lineages in D. harrisi characterised by frequency 
diff Je 
ferences from other lineages within the species. Whilst there are no examples of fixed allozymic 
tricted to particular geographic areas. The 
ifferences í 
e SRI some polymorphic loci have allozymes res 
€ example is the B-GAL 1 allozyme which is, with the exception of low frequencies in Al and 
» found in the southern and southeastern springs. Other instances include the LGG-1 2 allozyme 
