Data from: Altitudinal clinal variation in wing form in African Drosophila melanogaster: one cline or many?

Geographical patterns of morphological variation have been useful in
addressing hypotheses about environmental adaptation. In particular,
latitudinal clines in phenotypes have been studied in a number of
Drosophila species. Some environmental conditions along latitudinal
clines—for example, temperature—also vary along altitudinal clines, but
these have been studied infrequently and it remains unclear whether these
environmental factors are similar enough for convergence or parallel
evolution. Most clinal studies in Drosophila have dealt exclusively with
univariate phenotypes, allowing for the detection of clinal relationships,
but not for estimating the directions of covariation between them. We
measured variation in wing shape and size in D. melanogaster derived from
populations at varying altitudes and latitudes across sub-Saharan Africa.
Geometric morphometrics allows us to compare shape changes associated with
latitude and altitude, and manipulating rearing temperature allows us to
quantify the extent to which thermal plasticity recapitulates clinal
effects. Comparing effect vectors demonstrates that altitude, latitude,
and temperature are only partly associated, and that the altitudinal shape
effect may differ between Eastern and Western Africa. Our results suggest
that selection responsible for these phenotypic clines may be more complex
than just thermal adaptation.