But then how many of the fry (hybrid and non-hybrid) produced in these
periods survive to reproduce? I suspect that in a small tank, with people
caring for the fry there is a greater chance that the hybrids will survive
VS small pools in the dry season (poor water condiitons, insufficent food
supply etc. not to mention possible impaired fitness due to hybrid
incompatibility (missing enzymes, proteins, etc bizzare apperances). Then
we would only see a few in nature and infer that it didn't happen that
often. In an artificial situation the survivorship potential is greatly
enhanced. .....
> > and nigrans divered a longer time ago as compared to the divergence of
the
> > tris and splendida groups....
>
> Actually, everything so far suggests tris are the most distantly related
of
> all the Australian rainbows relative to each other and by a fair ways too.
Hmmm. Maybe diverged long ago, in isolation, and via changes in the local
geography has brough species back together recently? Then it would have
been possible to have situations in which physical/morphological
incompatibilities were not important and thus never developed (cryptic
species complexes?). Sort of like orchids (yes plant genetics are
different, especially in the case of orchids) as intergeneric hybrids are
possible as reproductive isolation is the product of geographical or
pollinator specific mechanisms
>
> Cheers
> Peter