The debate surrounding cichlid origins

[neutrino]

Cichlids 110-135 million years old (as asserted by theory) or 50-60 million years old (according to fossil evidence)?

...Gondwana origin for cichlids, a common and long held, but debatable and problematic, theory-- illustrating an issue with molecular dating, which typically needs to be "calibrated," and is sometimes done simply to support theory, absent, or contrary to, other evidence.
(wasn't certain where to post this, move it if necessary)

https://royalsocietypublishing.org/...5j87yKmXN04yDj4bNtKYraQUoRSd0gzncocL5IrMLosZs

 

[Crazylegs78]

I've really gotten into the evolutionary biology of cichlids recently simply because my OCD won't let me fill up my fish room with random fish that are not organized in some way. I was going with the Old World/New world division as its the simplest, but figure 1 from this paper will allow me to further organize based on evolutionary age. That makes my OCD feel better.

I think it's interesting how the Gondwanan vicariance models hold traction for so long when we are surrounded by examples of species that spend parts of their lives in different salinities. Why then is it so difficult to think that a common cichlid ancestor could have come from a saltwater environment? Conversely, the lobed fin fish relative of all land animals is a widely accepted theory....

Thanks for this!