Opening Minds to Ancient Times

How does working inside a remote Siberian ice cave filled with ancient, frozen creatures, or sifting through piles of petrified poop, sound to you?

It may not be the ideal job for many, but molecular evolutionary geneticist Hendrik Poinar can't seem to get enough. Whether it's unraveling the DNA from woolly mammoths or tracing the dietary habits of giant sloths, Poinar (pictured left) is bold, committed, and undeterred by conventional boundaries. "I don't shy away from knocking on people's doors, no matter if they're paleontologists, microbiologists, or anthropologists," says the 38-year-old associate professor in the departments of Anthropology & Pathology and Molecular Medicine at McMaster University in Hamilton, Canada. "I just love working at the crossroads of so many fields."

Relics

When Poinar learned about the cache of mammoth carcasses stored in a Cold War missile silo, he didn't hesitate to contact the paleontologist collector. He took bone-core samples and, in collaboration with a Pennsylvania State University team, adapted a method for large-scale sequencing of nuclear genomes that had never been used on fragmented, ancient DNA.

Poinar began laying the foundation for the work when he arrived on McMaster's campus as an assistant professor in 2003. Poinar established the McMaster Ancient DNA lab , where he and his team of graduate students, postdocs, and research associates seek novel ways of extracting DNA information. Using the latest polymerase chain reaction technology and techniques, his team has sequenced millions of base pairs of nuclear DNA from mammoths and other extinct species. "A year ago, everybody would have laughed," says Poinar. "Now the field is completely changed, and there's a big rush to sequence everything. Soon there will be a waiting list of extinct animals to sequence." Now, Poinar is seeking funding to sequence the mammoth genome. Once the DNA is mapped, the mammoth could find its place among its extinct and extant relatives. Would it be possible to bring the mammoth to life? It could happen, Poinar says.

Until recently, all he had to work with, he says, were dry, fossilized bones--but then he heard about the mammoth missile silo. "In these samples, the preservation is so good that you can have 40-, 50-, or even 60-thousand-year-old mammoths where fat would leak out of their bones as we drilled into them. In fact, as we were sawing and heating up the frozen mammoth bone, liquid blood would actually spray out."

Although most of his studies are on ancient DNA, some of his work focuses on more recent mysteries, including the molecular origins of medieval Europe's plagues (using bones taken from mass graveyards) and the source of the current HIV epidemic (using archival histological samples from wild chimpanzees). The goals, Poinar says, remain the same: "answering interesting biological and evolutionary questions that couldn't be done using traditional morphology."

He hasn't sat waiting for opportunities. Most of the projects on his long lineup he initiated himself, usually by making phone calls and selling himself and his ideas to other researchers. "I never e-mail; I just call, and usually I can tell on the phone whether they're interested or not in my proposals," Poinar says. "Generally, I find that people are attracted to enthusiasm if it's unfettered and for the right reasons."

That's exactly how Ross MacPhee, a curator of vertebrate zoology at the American Museum of Natural History in New York City, says he was hooked. "He is a master of the game when it comes to starting collaborations," says MacPhee. "I think Hendrik intuitively recognizes that if you're going to make the field progress in a way that it should, it's very important to get people with different abilities together." Since beginning their joint project on the giant sloth 3 years ago, they have been working to figure out what these elephant-sized mammals ate and why they went extinct more than 10,000 years ago. Poinar's ability to coax plant DNA out of their fossilized feces, MacPhee says, has "opened up new insights not only on the sloths themselves but the world around them."

Jurassic start

Some of these ventures, such as the sequencing of extinct species genomes, have drawn the attention of the science community and the media. Poinar has published inScienceandNatureand contributed to television documentaries. But this kind of attention is nothing new for him; he grew up with it. Poinar is the second generation in his family to study ancient forms of life, following in the footsteps of his father, a well-known paleoentomologist. Poinar credits his father with teaching him the importance of having great depth in a narrow niche while never losing the big picture. "He definitely shaped my career, and I think that's where I learned to become more of a horizontal scientist rather than a vertical scientist." Poinar says. "I'm usually bridge-building where disciplines meet each other rather than [working in] one specific area."

When he was starting college in the early '90s, Poinar remembers sitting in on discussions within his father's research team while they argued about the possibility of extracting ancient DNA. "They used to joke about bringing back dinosaurs from their blood inside insects encrusted in amber," he says. Not much later came Michael Crichton'sJurassic Park, and his father's team acted as scientific consultants for both the book and movie. Those early discussions between paleontologists and molecular biologists had an impact on the younger Poinar. He knew right then what he wanted to do.

Nearly 2 decades later, the promise of bringing dinosaurs back to life is still remote, but it's a provocative way of starting a discussion on the ethics of resurrecting extinct organisms--such as mammoths. It's also a great way, he says, to stimulate public interest in his field. "Some molecular biologists have shied away from it, but I think it does throw light on ancient DNA research and evolutionary genetics in a positive way."

But Poinar says that regardless of what the future holds, he will never forget his mammoth-sampling summers. He spent many hours scouring the Siberian tundra, then trekking back to the site and using high-pressure water pumps to carve the frozen animal out of the ground and taking it back to an ice cave for storage and sampling.

Poinar finds this kind of intimate, hands-on contact with these mythical giants of the past more than gratifying. "It just doesn't get any more exciting than that," he says. "These are the times I can't help but say I love what I do."

Andrew Fazekas is a correspondent at Science Careers and may be reached at afazekas@aaas.org.

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DOI: 10.1126/science.caredit.a0700066