Network reconstructions. Median-joining network analyses for the Zaprionus and the melanogaster species. The size of each circle denotes the number of sequences grouped together. (a) Network for the Gypsy retroelement. Each group obtained in the phylogenetic tree is differently colored. (b) Detail of the Gypsy Subfamily 2. (c) Network for the Micropia retroelement. The sequences are colored according the clustering in the phylogenetic tree. The black arrows show the HT events evidenced by network trees.