Department of Molecular Biology, The University of Medicine and Dentistry of New Jersey, B303 Science Center, 2 Medical Center Drive, Stratford, NJ 08084, USA. ron.ellis@umdnj.edu
A new study showing that neither FEM-2 nor FEM-3 is required for spermatogenesis in Caenorhabditis briggsae, unlike in Caenorhabditis elegans, implies that the sex-determination pathway in these species is evolving rapidly, and supports the proposal that they evolved hermaphroditism independently.