Published November 20, 2008
WASHINGTON – Scientists for the first time have unraveled much of the genetic code of an extinct animal, the ice age's woolly mammoth, and with it they are thawing Jurassic Park dreams.
Their groundbreaking achievement has them contemplating a once unimaginable future when certain prehistoric species might one day be resurrected.
"It could be done. The question is, just because we might be able to do it one day, should we do it?" asked Stephan Schuster, the Penn State University biochemistry professor and co-author of the new research. "I would be surprised to see if it would take more than 10 or 20 years to do it."
The million-dollar project is a first rough draft, detailing the more than 3 billion DNA building blocks of the mammoth, according to the study published in Thursday's journal Nature. It's about 80 percent finished. But that's enough to give scientists new clues on the timing of evolution and the deadly intricacies of extinction.
The project relied on mammoth hair found frozen in the Siberian permafrost, instead of bone, giving biologists a new method to dig into ancient DNA. Think of it as CSI Siberia, said Schuster. That different technique — along with soaring improvements in genome sequencing and the still embryonic field of synthetic biology — are inspiring scientists to envision a science-fiction-like future.
Crucial to the mammoth mapping are about 20 hairballs. Past efforts to use ancient DNA were hampered because bacteria, viruses and parasites crept into the bone fossils during the millenia-old degradation process, making much of the found genetic material something other than what scientists study. For example, current efforts to study Neanderthal DNA have been complicated because only about 6 percent of the recovered genetic material actually belonged to our ancient cousins.
Schuster says that it should be possible to someday recreate any extinct creature "within the last 100,000 years" as long as it got trapped in permafrost and had hair. But that leaves out the Jurassic Period, the time of dinosaurs.
So Earth's real-life sequel to extinction is far more likely to be Ice Age 3 than Jurassic Park IV.
Three years ago, Japanese scientists said they planned to find frozen mammoth sperm and impregnate an elephant and raise the offspring in a safari park in Siberia. But using genetics to engineer a mammoth makes more sense, Schuster said.
Anthropology professor Hendrik Poinar of McMaster University in Hamilton, Ontario, said he no longer considers such ideas impossible. Poinar, who wasn't part of Schuster's study but consulted on the movie Jurassic Park, said director Steven Spielberg may have had it right when he told skeptical scientists: "This is the science of eventuality."
And it doesn't have to be a full resurrected mammoth. Scientists could examine what makes the mammoth different from its closest cousin, the African elephant, and create a hairy hybrid to sit in zoos, said George Church, director of computational genomics at Harvard Medical School: "People would like to see a hairy elephant."
Alex Greenwood, a biology professor at Old Dominion University who also studies ancient DNA called the research "an amazing achievement."
The more practical side of what this new research will do is point out better the evolutionary differences between mammoths and elephants and even humans and chimps, said Church, who wasn't part of the study.
Elephants and mammoths — comparable in size at about 8 to 14 feet tall — diverged along evolutionary paths about 6 million years ago, about the same time humans and chimps did, Schuster said. But there are twice as many differences between the genetic makeup of chimps and humans as those between elephants and mammoths.
"Primates evolved twice as fast as elephants," Schuster said. But some animals such as rodents have had even more evolutionary changes, indicating that it might have to do with size or metabolism, said study co-author Webb Miller.
Another interesting finding is that in the 50 or so species with mostly mapped genomes, there are certain areas where the genetic code is exactly the same in all the animals — except the mammoth.
In other animals these, proteins "stayed the same for a very long time except in the woolly mammoth," said Miller, professor of biology and computer science, also at Penn State. "I don't know what it means. All I did was find them."
Miller and Schuster noticed that most of the mammoths they examined had far less genetic diversity than other species that are still alive and that may also give a clue into the biology of extinction.
So the duo are also applying what they learned from the cold Siberian behemoth to their other efforts to help save the endangered Tasmanian devil of Australia. They notice the same dramatic lack of genetic diversity in that modern day creature, Schuster said.