Comb jellies are helping answer fundamental questions in biology, from how the earliest nervous systems evolved to how bioluminescence works. A round 700 million years ago , a group of organisms resembling little more than glowing, gelatinous blobs split off from the rest of the animals, forming possibly the earliest branching animal lineage. Nearly 200 species of ctenophores, commonly known as comb jellies (but unrelated to jellyfish), live today in environments ranging from the cold depths of the sea to warm coastal surface waters. Their magic isn’t just in their persistence or iridescence; it’s in their DNA. Over the past decade, ctenophores have helped answer long-standing questions about fundamental biology, from how early nervous systems evolved to the origins of the mesmerizing phenomenon of bioluminescence .…