> Have any of you heard of the little fish Galaxis zebratus? It is
> common here in the Cape Province in South Africa. Its nearest
> family is in Argentinia and Australia. If a fish can stay in the same
> genus over a few million years and thousand km then a land bridge
> that vanished 6000 yrs ago is just as feasable for explaining the
> relationships between AU and NG fish.
Actually, they most likely are not the same genus, recent genetic stuff by Jon
Waters suggests they are mostly closely related to Brachygalaxias/Galaxiella.
Molecular clock estimates ranged between ~14 and 30 million years, hence they
are most likely a freshwater vicariant dating back from the separation of the
southern continents unlike some of the species which have probably dispersed
via marine environments.
Tootles
Peter