Fig. 5. Unrooted phenetic similarity tree of wing landmark sexual dimorphism of three wildtype Drosophila melanogaster strains.  The 'best' tree of morphological distances was computed based on the Kitch algorithm of Felsenstein (1989) applied to pair wise Procrustes distances computed using the tpsSmall algorithm applied to the set of six average landmark sets computed for the two sexes of three wild type D. melanogaster strains.   A (default) Kitch analysis was performed on the Procrustes difference matrix (Table I) using the Fitch-Margoliash method with contemporary tips.  Negative branch lengths were not allowed and 123 trees were examined.  The Drawtree algorithm was used to create the unrooted tree using computed limb lengths.  Subsequent analysis of 300 wings of the three stains concluded that there is no significant difference in the observed sexual dimorphism between the three stains.