Thoracic trident pigmentation in Drosophila melanogaster: latitudinal and altitudinal clines in Indian populations AK Munjal, D. Karan, P. Gibert, B. Moreteau, R. Parkash and JR David Genet. Sel. Evol., 29 5 (1997) 601-610 DOI: 10.1051/gse:19970505