Wright's analyses indicate that there are at least two independent evolutionary origins of catfish venom glands. In addition, the toxic peptides show strong similarities with, and might be derived from, previously characterized toxins found in catfish epidermal secretions. "Further examination of the chemical composition of the venoms will provide valuable insight into the mechanisms and potential selective factors driving venom evolution in fishes," comments Wright.
How did such similar glands evolve independently? By the action of natural selection, evolutionists will tell you. With similar environments you have similar selective factors and, therefore, similar designs.
This explanation avoids the awkward detail that natural selection never created anything. It kills off the designs that don't work, but the selected designs had to be created, one step at a time, in the first place. Those steps don't simply appear spontaneously given selective factors, no matter how many times evolutionists suggest this.
So we must believe evolution is continually generating untold myriad designs from which to choose. It is mostly worthless junk since evolution is all a fluke in the first place, but rare gems luckily appear now and then, and sometimes they are strikingly similar. How odd. Oh well, I guess we just live in the right universe.
There are evolutionists who deny the massive convergence in biology, and those who deny the implications of the massive convergence in biology. Religion drives science, and it matters.