In 1641, French philosopher René Descartes, writing his famous “Meditations on First Philosophy,” observed that a mind is fundamentally different from the body which contains it. He reasoned that, while physical objects like flesh and bone can be divided or merged together, consciousness is intrinsically different because it cannot be quantified. Scientists have long known that it is impossible to separate or fuse a conscious mind — at least, that is what they thought.
Yet a pair of recent studies about comb jellies raise provocative questions about Descartes’ maxim. The first is a study from the journal Current Biology found that ctenophores, a phylum of aquatic invertebrates better known as comb jellies, can successfully fuse together after being injured. (Though the animals have a striking weirdness and similarity to jellyfish, they are not technically related.) The scientists studied a population of warty comb jellies (Mnemiopsis leidyi) in a tank, gazing in amazement as two organisms bonded with one another with the flesh, seamlessly integrating as if to form a single new animal.
