A couple of years ago I read an article about an experiment where the genes of a jellyfish were spliced into a rabbit - the result: a rabbit that glowed in the dark. My question is, science aside, is this a rabbit?

Good question.

I'm not sure that there's any answer "science aside", since the notion of being a member of a given biological species (in this case, some sort of rabbit) is a scientific concept. It is up to science to tell us what species are, whether there are any such things, why they arise and go extinct, and so forth.

One popular conception of a biological species is that a species is a group of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups. In other words, members of the same species form a united gene pool, so that a beneficial adaptation appearing in that pool could spread throughout it, whereas barriers prevent its spreading outside of the species.

On this view, which is obviously motivated by evolutionary considerations, the mere fact that the creature you have mentioned differs from all (other) rabbits in possessing certain genes that allow it to glow in the dark does not rule out the possibility that it is a rabbit. After all, rabbits differ from each other in a great many respects. This variation is the raw material for natural selection. Perhaps the experiment merely introduced a new sort of variation into rabbits.

On the other hand, it could be that this gene would prevent the creature from being able to interbreed with rabbits. Perhaps a rabbit would be too frightened by the glow to mate with it. Or perhaps the gene for glowing also makes the creature sterile. If so, then the creature you have mentioned would not qualify as a rabbit by the above conception of what a biological species is.

Another point: You haven't said whether the creature was returned to the wild after it was experimented upon. If not, then it belongs to no "natural population" (though it once did) and so is not a rabbit (or a member of any other biological species), by the above conception of what a biological species is. That's a tough break for zoos, don't you think?

Of course, the above definition is not the only conception of what a biological species is. However, if the creature was born from rabbits, and if its offspring would be rabbits, then it would be difficult to deny that it is a rabbit.

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