We hypothesised that long-term earthworm colonizers of heavily polluted met
alliferous soils in the vicinity of abandoned Pb/Zn-mines have; responded g
enetically to the selection pressures imposed upon them by the edaphic cont
aminants such that they have evolved into locally differentiated, metal-ada
pted, ecotypic populations. The hypothesis was tested by measuring and comp
aring the growth rates up to 36 weeks post-hatching of the F1 generation of
fspring of adult Lumbricus rubellus collected from four distinct sites: a c
lean calcareous reference site; a clean acidic reference site; a calcareous
mine site; an acidic mine site. Four subsets of each of the four Fl popula
tions separated, with one subset grown on food-supplemented soil of parenta
l origin, and one subset allocated to each of the other 'experimental' fiel
d-collected soils. Growth did not yield compelling evidence of metal adapta
tion in either of the two mine-derived F1s. Different organism groups explo
it different life-history strategies to cope with environmental stress. Thi
s tenet justifies our intention to extend our observations on F1s beyond 36
weeks to encompass reproduction endpoints. Two further Findings were notwo
rthy: fa) soil pH is a major determinant of juvenile earthworm growth; fb)
plotting the growth data for individual worms representing the F1 offspring
of parents inhabiting the acidic mine soil revealed two distinct phenotype
clusters, one with a significantly faster growth rate than the other.