Cavefish: A Study in Evo-Devo (interview)

Why are cavefish a good example of evo-devo? The blind Mexican cavefish is one of the few species that has an ancestor on the surface and a descendent in caves. Jeffery: Scientists study all kinds of organisms in evolutionary developmental biology, but when I started working in the evo-devo field, I decided that in order to understand how development evolved, we would have to look at two closely related species that have diverged recently [developed in separate directions] or to look at the same species in the process of divergence. I looked around for models, and I found several of them. One of them happened to be in caves, and the species is called Astyanax mexicanus, the blind Mexican cavefish. This cave organism is one of the few in which the acknowledged ancestor is still present on the surface, and the descendent organism is still present in the caves. They are the same species but they are in the process of divergence. These species can breed with one another, which allows for the genetic study of interesting traits. This combination of special circumstances fits my criteria for ideal development models. We could determine what the ancestral situation looked like by studying today’s surface fish and examine what the derived species looked like by studying present cavefish. After the divergence, how do the cavefish differ from their surface counterparts? Jeffery: Well, actually, we can study this very nicely in caves, particularly in Mexico. Cavefish populations w...
Source: ActionBioscience - Category: Biology Authors: Source Type: news