This should help from Near et al.


TEMPO OF HYBRID INVIABILITY IN CENTRARCHID FISHES by DANIEL I. BOLNICK AND THOMAS J. NEAR :


" The only crosses with total inviability in
both directions are M. salmoides 3 (Ambloplites rupestrus,
Pomoxis annularis, or Pomoxis nigromaculatus) at 28.94 million
years, while 10 other crosses of that age have some
viability in one or both reciprocal directions (see online Appendix).
Centrarchids also retain nonzero viability and heterosis
for much longer than most other taxa."












Last edited by ewest; 03/07/12 09:52 AM.