Jellyfish Genome Hints That Complexity Isn’t Genetically Complex

Jellyfish Genome Hints That Complexity Isn’t Genetically Complex

An overarching theme in the story of evolution, at least over the past half billion years or so, is rising complexity. There are other themes, of course, but life has undoubtedly become more complicated since its origin. Early cells globbed together to form multicellular coalitions. Those developed more complex bodies and lifestyles as the millennia passed, finding ever more varied ways to make a living. You might expect that as bodies became more complex, genomes did as well.

But a recent study appearing in Nature Ecology & Evolution shows that not to be the case — at least for jellyfish, humble organisms that evolved at a crucial juncture in animal history. They did not need more genes — or even notably different ones — to power their giant leap in complexity. This new study adds to a growing body of work that casts doubt on finding straightforward genomic signatures of the evolution of complexity.