the bones of a strange flat-headed, fish- ALUMNI cum-crocodile-like creature-with-a-neck that he and colleagues had found the year before while scraping away at ancient rocks in the Canadian Arctic. Fishing for Answers Roughly 375 million years old, from the Late Devonian period, the fossilized crea- ture was a genus of the extinct sarcop- A paleontologist looks at the origins of the human body. terygian (lobe-finned) fish that shares sev- eral key features with tetrapods (early n 2005, parents and school o∞cials parents’ favor, deciding that the require- four-legged animals). In addition to the in Dover, Pennsylvania, were locked ment was unconstitutional. Throughout neck and non-conical head, Tiktaalik roseae, in a courtroom debate over a school- the trial, paleontologist Neil Shubin, as it was named, boasted expanded ribs board mandate that intelligent de- Ph.D. ’87, Bensley professor in the depart- and parts of a shoulder, along with Isign be presented as an alternative to evo- ment of organismal biology and anatomy webbed fins—inside which were also lution in ninth-grade science classes. The at the University of Chicago, struggled to primitive bones corresponding to an upper judge in the case ultimately ruled in the remain quiet in his o∞ce: on his desk lay arm, forearm, and pieces of a wrist. All are explicitly non-fish features. Shubin and Neil Shubin other scientists say Tiktaalik helps bridge the gap in our understanding of what changes occurred as sea animals crept ashore, and plays a critical role in under- standing—and proving—human origins. “During the Dover trial, I couldn’t tell anyone apart from colleagues about our find,” Shubin says now, with a smile: the news was an exclusive, scheduled to be an- nounced in Nature’s April 2006 cover story. Most of the nation’s news media, major publications, and science magazines fol- lowed up with articles about Tiktaalik (the word means “large, freshwater fish” in the Inuktitut dialect of Inuit). Hailed as “the fish that crawled out of the water” and “the missing link,” Tiktaalik is by far the most important discovery of Shubin’s career, which has centered on the evolution of limbed beings. “I’ve devoted my life to this evolutionary biology stu≠—I love it,” he exclaims. “I enjoy going to work because it’s fun working with worms, fish, and salamanders. I think it’s beautiful that remedies for the problems we su≠er from will be found by seeing pieces of us nestled in the most primitive and humble creatures that live on the earth.” His new book, Your Inner Fish, is an infec- tious exploration of the 3.5-billion-year history of the human body. It traces our organs back to fossils and prehistoric DNA—how our arm and hand bones came from fins; how our teeth first formed as spiky structures in the mouths of tiny, an- cient, jawless lamprey-like fish known as conodonts; and how major aspects of our genome are similar to those of worms. Our Photograph by Ralf-Finn Hestoft ability to talk, for example, depends on on an urban archaeo- the larynx, which is composed primarily logical site and “loved of cartilage akin to the gill bars in a fish or ancient Egypt and Tu- shark. Even hiccups—a nerve spasm and tankhamen and see- inhalation, followed almost immediately ing the past inside (35 milliseconds, Shubin writes) by the the dirt,” he explains. “hic” sound—are the product of our “Paleontology pulled shared history with fish and tadpoles, re- me into the immedi- spectively. And the process through which acy of discoveries. If teeth first formed in fish—at base, from you know where to the interaction between two layers of tis- look, and crack in- sue—is the same process involved in the side the rocks, and subsequent development of scales, hairs, find a physical piece feathers, and sweat glands. of evidence that can Shubin says he wrote the book to ex- change the way we Remains, and a reconstruction of what researchers believe Tiktaalik roseae plain his work to his father, Seymour Shu- look at our past— looked like as it roamed its corner of the bin, who still writes crime novels and this struck me as earth millions of years ago thrillers for a living at 87. “I gave him the very powerful.” At first draft and he said, ‘I don’t understand Columbia, he majored in biology and an- a few teeth best seen under a microscope. it,’” Shubin said at a winter reading at Har- thropology, which led to paleontology and The remains of this tritheledont, previ- vard Book Store in Cambridge. “He told then doctoral work at Harvard. ously linked only to South Africa, me, ‘Neil, nobody ever lost money writing In the 1980s, academic research in showed it had a human way of chewing a page turner.’ I said, ‘Dad, I’m a scientist. anatomy and development focused on the food. “I had an idea for field research and COURTESY OF NEIL SHUBIN We don’t write page turners.’ But I wrote relationships between living creatures Harvard had the resources to support it over again. And this time he liked it.” and fossils on the cellular level, using em- this independent research,” he says. “If Your Inner Fish, in fact, is something of an bryos. “Only a handful of people were that hadn’t existed, I wouldn’t be here adventure tale. It pulls in the reader even doing it, and few as well as those at Har- talking about all of this today.” though the Tiktaalik discovery took six vard,” Shubin points out. (This was be- By now, his main academic interest was years and four often frustrating, error- fore new technological tools enabled sci- the morphology of the tetrapod limb. filled trips into deep wilderness to com- entists to work on the molecular level.) Working with the embryos of salaman- plete. “For starters, there were polar His first Harvard-a∞liated expedition ders, frogs, and fish, Shubin wrote his dis- bears,” says Shubin, a city boy from came in 1983, on the field team of profes- sertation on developmental biology and Philadelphia. “And polar bears eat peo- sor of biology and curator of vertebrate the similarities between fins and limbs. He ple.” On the group’s first expedition to paleontology Farish A. Jenkins Jr., who spent the next two years doing postdoc- the Canadian Arctic, in 1999—which was working in the American West, toral work at the University of California, Shubin calls a “colossal bad choice” all looking for new sites and early mammals Berkeley, where he also met and married around—they took rifles and motion de- that could help explain how humans de- geologist Michele Seidl ’85 (now director tectors, which they set up in their tents veloped the ability to chew. Shubin of planning for biological sciences at the before going to sleep. Not long after, the writes that the mammalian method for University of Chicago). An 11-year stint at detectors went o≠ and everyone jumped chewing first emerged in fossil records the University of Pennsylvania followed. up, cocked their guns, and raced outside. dating from 225 million to 195 million Nothing was there. This scenario played years ago, in big-headed reptiles that At penn, and still searching for the ori- out at least four times before someone re- walked on all fours and had bony jaws gins of limbed creatures, Shubin focused alized that it was not lurking man-eaters with teeth that fell out and re-grew his sights on the already well-studied setting the detectors o≠, but ferocious throughout their lives. Catskill Formation of Pennsylvania. In the winds. “These detectors were made for Having finally learned how to spot Late Devonian age, when Shubin and oth- suburban New Jersey, not the Arctic,” bones in the dust, mud, and dirt, Shubin ers say some animals were making the Shubin jokes. “You’ve just got to learn in grew eager to lead his own trip. He ex- switch from sea to land, this region was fieldwork that you never get it just right.” plored 200-million-year-old Connecticut akin to today’s Amazon River delta, he rocks a half-day’s trip away from Cam- notes, with many streams draining into a That wasn’t the first field trip to leave a bridge before expanding to Nova Scotia; large sea where Pittsburgh now stands. In strong impression on him. As a child, he ultimately, he found enough bones to fill 1993, he and one of his graduate students, loved going to museums, especially the a few shoeboxes among the sandstone Ted Daeschler, began visiting rock zones Academy of Natural Sciences in Philadel- cli≠s in the Bay of Fundy. Among them recently blasted out by the state trans- phia and the Natural History Museum in was a significant find: a piece of an early portation department to prepare for more New York City. In high school, he worked mouse-like mammal with a tiny jaw and roadways. To their surprise, Shubin relates www.haa.harvard.edu Harvard Magazine 79 JOHN HARVARD’S JOURNAL in Your Inner Fish, Daeschler one day found and was experienced enough to help camp on time. “We were very worried, “a marvelous shoulder bone” that they them: Farish Jenkins. (Later that day, but then he came limping into the cook named Hynerpeton, Greek for “little creep- Shubin adds, he and Daeschler went to a tent with a wild-eyed stare, like he’d been ing animal from Hyner,” Pennsylvania.