Fig. P1.

(A–L) NMJ morphology among different species of Drosophila varies extensively and does not exhibit an obvious pattern on the basis of evolutionary relatedness. Larvae of each species were dissected and stained to highlight motor nerve terminals on the muscle surface. The small beadlike structures are synaptic boutons or nerve terminals. There is substantial variation in NMJ morphology among these species in overall geometry, length, and complexity. The phylogenetic tree is based on the complete genomic sequence of these species. Examination of the data reveals no apparent relationship between the evolutionary distance separating two species and their morphological similarity as quantified either by bouton number or by number of synaptic branches.