This is fascinating. Thanks. I wonder if this mechanism is similar to polydactylism in cats (extra toes and even feet). This condition is much more common in cats than other mammals for some reason.
Thank you for your question. The mechanisms of polydactylism and twin-tail/dorsal-fin, they have similar/dissimilar points. Toes and feet are not axial skeleton, so relating genes of these appendicular skeleton are differnt from that of axial skeletons (caudal fin). But due to the pleiotropy, some genes might be overlapping between appendicular and axial skeletons at a certain level. To know how are they related, not only evolutionary study but also developmental biology, both reseaches are required, I suppose.
@ Reading a bit more about polydactyl cats it seems like it’s a mutation that affects fetal development which can sometimes result in a birth defect. With these goldfish it seems like it’s a mutation coded in the actual blueprint of the fish body structure. At least, that’s my amateur interpretation.
Yes yes. Something like that. The blueprint of the vertebrate (including fish, mammals and so on) body structure should not be mutated, but the mutated blueprint works only in the goldfish. Since the mutated blueprint cannot work in most of mammals, the "twin-tail cat" is really rare (or almost nothing such mammals).
This honestly blew my mind.
Thank you. I think I will make an independent channel dealing only with goldfish EvoDevo
This is fascinating. Thanks. I wonder if this mechanism is similar to polydactylism in cats (extra toes and even feet). This condition is much more common in cats than other mammals for some reason.
Thank you for your question. The mechanisms of polydactylism and twin-tail/dorsal-fin, they have similar/dissimilar points. Toes and feet are not axial skeleton, so relating genes of these appendicular skeleton are differnt from that of axial skeletons (caudal fin). But due to the pleiotropy, some genes might be overlapping between appendicular and axial skeletons at a certain level. To know how are they related, not only evolutionary study but also developmental biology, both reseaches are required, I suppose.
@ Reading a bit more about polydactyl cats it seems like it’s a mutation that affects fetal development which can sometimes result in a birth defect. With these goldfish it seems like it’s a mutation coded in the actual blueprint of the fish body structure. At least, that’s my amateur interpretation.
Yes yes. Something like that. The blueprint of the vertebrate (including fish, mammals and so on) body structure should not be mutated, but the mutated blueprint works only in the goldfish. Since the mutated blueprint cannot work in most of mammals, the "twin-tail cat" is really rare (or almost nothing such mammals).