ALTITUDINAL CLINAL VARIATION IN WING SIZE AND SHAPE IN AFRICAN DROSOPHILA MELANOGASTER: ONE CLINE OR MANY?
Article first published online: 7 SEP 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 2, pages 438–452, February 2013
How to Cite
Pitchers, W., Pool, J. E. and Dworkin, I. (2013), ALTITUDINAL CLINAL VARIATION IN WING SIZE AND SHAPE IN AFRICAN DROSOPHILA MELANOGASTER: ONE CLINE OR MANY?. Evolution, 67: 438–452. doi: 10.1111/j.1558-5646.2012.01774.x
- Issue published online: 28 JAN 2013
- Article first published online: 7 SEP 2012
- Accepted manuscript online: 9 AUG 2012 12:38PM EST
- Received April 2, 2012 Accepted July 22, 2012 Data Archived: Dryad doi:10.5061/dryad.r43k1
- geometric morphometrics;
- thermal plasticity
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.