Laboratory Statistics and Genomes, CNRS - Génopole Evry, F EMBL-Heidelberg, Germany. nicodeme@genopole.cnrs.fr|Laboratory Statistics and Genomes, CNRS - Génopole Evry, F EMBL-Heidelberg, Germany. nicodeme@genopole.cnrs.fr|Laboratory Statistics and Genomes, CNRS - Génopole Evry, F EMBL-Heidelberg, Germany. nicodeme@genopole.cnrs.fr