| distribution and stability of supernumerary microchromosomes in natural populations of the amazon molly, poecilia formosa. | in animals, supernumerary chromosomes and their evolution have mostly been studied in sexual reproducing species. in the present study, for the first time, the natural distribution and stability of supernumerary microchromosomes were investigated in the unisexual fish species poecilia formosa. natural habitats throughout the range of p. formosa were screened for the presence of microchromosomes over several years. a high frequency of microchromosomes was found in the río purificación river syste ... | 2004 | 15292590 |