Defensins and the convergent evolution of platypus and reptile venom genes. by Whittington, C, Papenfuss, A, Bansal, P, Torres, A, Wong, E, Deakin, J, Graves, T, Alsop, A, Schatzkamer, K, Kremitzki, C, Ponting, C, Temple-Smith, P, Warren, W, Kuchel, P, Belov, K