Draw a line back through time from today’s person, panda, porpoise, pelican, or perch and it ought to end with their earliest progenitor. In the mists of the ancient past, a single organism must have given rise to us all. But that raises an interesting question: Where did this animal come from? What did it look like? And what are its nearest living relatives?
To understand what the first animals looked like, Mitchell Sogin, an evolutionary microbiologist at the Marine Biological Laboratory in Woods Hole, Massachusetts, used advanced automated DNA technology and computing power to trace the molecular evolution of dozens of today’s oldest known species—jellyfish, sea anemones, sponges, mollusks, starfish—back to their common point of origin. When he grouped the species in the precise order of their appearance on Earth, from less complex to more complex, he landed on sponges.
Even Sogin was taken aback. “Sponges didn’t seem like animals—they didn’t go seeking prey, didn’t have 4 legs—or 10 legs. Show Joe Blow a sponge and it looks like cauliflower. But it’s not. It’s an animal.” Perhaps even more intriguing, Sogin uncovered something older in the animal line than sponges that isn’t an animal: fungi. “That’s surprising,” Sogin says. His findings have implications for evolutionary studies and may even shed light on the shape of extraterrestrial life. The discoveries have already made contributions to medicine. “He’s a pioneer in the systematic application of this method,” says evolutionary biologist W. Ford Doolittle of Dalhousie University in Nova Scotia. “It’s a very great achievement.”
Not bad for a Chicago kid who “never expected to become a scientist” and in fact had “no driving career ambitions” when he went to school. Now, sitting in his cluttered Woods Hole office, the soft-spoken biologist says, “It seems to be the big questions that appeal to me.” He opened his lab in 1989 with 5 people (now 10) and eight years later founded the Josephine Bay Paul Center for Comparative Molecular Biology, which he directs. Both are funded by the National Institutes of Health, the National Science Foundation, and NASA. He gazes out the window at icy Eel Pond and Buzzard’s Bay beyond it, then throws a wistful glance at a photo of Woods Hole in summer, when he sails his wife’s 41-foot Beneteau sloop, Origins.
