Dinosaurs and other extinct creatures have fascinated us and scared us as bones in museums, computer simulations in movies and even life-size replicas on amusement park rides. And scientists are working -- and have been for a long time -- to bring them back to us like a real-life Jurassic Park.
But don't get any ideas about dino blood from a mosquito for this one. Scientists have a more reliable vessel for preserving ancient DNA. Hair.
CBS 60 Minutes has an update on the progress of being made to bring extinct animals back to life:
"Just the study of ancient DNA only broke onto the scene 20 years ago or so. The idea that we could harvest DNA from extinct creatures, from fossil bones, learn something about the past," Sean Carroll, a professor of molecular biology and genetics at the University of Wisconsin, told CBS News Reporter Lesley Stahl.
Carroll says that like so many things in the field of DNA, the progress has been staggering.
Scientists recently discovered that the hair shaft seals DNA inside it like a biological plastic, protecting it, and making hair a rich and plentiful source of genetic information.
What Carroll said is the most important aspect of the DNA is its quality.
It's sort of like 'CSI,' you know? How good is this forensic material? Can you get good DNA information from older and older and older material?
According to 60 minutes, scientists from Penn State were able to sequence almost all of the wooly mammal genome out of just a few clumps of hair.
In terms of actually taking this DNA and making a T-Rex? The science isn't quite there yet, but researchers are looking into two options: taking a live relative of the extinct animal and matching its live genome to the extinct, and -- more simple -- cloning. Cloning is how the actor scientists in the Jurassic Park movies did it.
There are still a couple challenges with cloning. You have to have the full sequence, which 60 minutes reports is almost a reality for the wooly mammoth. And you have to have an intact cell, which is a bit tricker. An intact wooly mammoth cell has yet to be found, but Caroll says is not impossible:
"It could be a skin cell. It could be any particular cell that hopefully has been preserved well enough, stayed frozen for thousands of years and to transfer the nucleus of that cell into, for example an egg of an elephant," Carroll explained.
Watch the 60 Minutes segment:
The concept of harvesting DNA to restore these extinct animals to life is nothing new. In 2010, the Daily Mail reported scientists finding well-preserved DNA in the egg shells of an extinct bird. In fact, an extinct animal has already been restored to life using preserved DNA: the quagga. The invasive mussel populating the Great Lakes these days was named after the quagga, which was a subspecies of Zebra that went extinct in 1884. In 1983, the quagga was brought back to life using the cells of one of its other Zebra relatives and preserved DNA.
But quaggas were brought back only 100 years after extinction. There are more challenges for animals that are considered 10,000 or more years extinct. Aside from quality of DNA degenerating, cloning poses an issue as related animals become less and less related over time. 60 minutes has more:
"You don't just clone some cells and then all of a sudden you have a baby. I mean, there's so many scientific steps along the way, knowing everything from hormones to the proper surrogate to, you know, length of pregnancy," [Betsy Dresser of the the Audubon Nature Institute] explained. "Because, see, we don't know how long a woolly mammoth, the gestation period. We can guess, but we don't know, really."
. . .
"You know, there are still people who get nervous at the idea of cloning. They think there's something wrong about it," Stahl remarked.
"I'll tell you what, if you have to choose cloning or extinction, I'm gonna choose cloning. But I wanna be darn sure that I know how to do it. And if we don't do it while we have the animals now to be able to learn how to do it, then we're not gonna have a choice. It's not gonna be an option," Dresser said.
So to keep her options open while she's mastering interspecies cloning, she's also putting as many animals as she can on ice, literally.
Dresser is keeping skin samples of thousands of species inside tanks cooled with liquid nitrogen -- she expects they could remain viable as cells for at least hundreds of years -- in case they are ever needed to prevent extinction of a species or to bring one back.