Call it a case of science imitating art imitating science.
Rival research teams have found that fossil insects embedded in amber for as long as 30 million years still contained DNA fragments, bits of genetic material carrying their original genetically coded messages. The DNA samples, found in extinct species of termites and bees, are said to be the oldest yet discovered.
The notion of extracting DNA from insects in amber is the premise of "Jurassic Park," the 1990 Michael Crichton science-fiction novel. The plot involves a rogue scientist who extracts DNA from fossil mosquitoes. In the fictional case, however, the DNA is in blood cells that the insects sucked from dinosaurs. The scientist uses the dinosaur DNA to recreate living dinosaurs.
As it happens, Crichton got some of his ideas back in the 1980s when one of the scientists who made the new discoveries was first talking up the idea of looking for ancient DNA in amber-entombed insects.
"A lot of people back then thought we were crazy," said George Poinar of the University of California at Berkeley, who in 1980 organized colleagues into something called The Extinct DNA Study Group. "Crichton heard about us and we started sending him some of our papers and our newsletter."
Last month Poinar and his colleagues published a paper in Medical Science Research, a British journal, reporting that they had found DNA fragments in bees trapped in 30-million-year-old amber and that they had read its genetic sequence.
In today's issue of Science, four researchers from the American Museum of Natural History in New York -- Rob DeSalle, John Gatesy, Ward Wheeler and David Grimaldi -- report similar findings from a termite in amber believed to be between 25 million and 30 million years old. They say the findings are leading to a reinterpretation of termite evolution.
Until now, the oldest recognizable DNA was extracted from magnolia leaves that had been preserved in sedimentary deposits for 17 million years.
Both groups used amber from the Dominican Republic, one of the world's largest sources of the substance. Amber is hardened tree resin, which can ensnare insects and other small creatures while it is still soft and sticky. Because it is a natural antibiotic, the trapped creatures do not decompose. Some components of the amber are thought to soak into the organisms, helping preserve their internal organs.
"We got this idea when we sectioned some insects in amber and looked at them under the microscope," Poinar said. "We were amazed at all the cellular structures we could see, including nuclei."
If nuclei were so well preserved, Poinar thought, perhaps their contents -- the chromosomes, each of which contains thousands of genes -- would be too.
The chance of recreating extinct life forms remains remote. For one thing, the ancient DNA is badly damaged. In life, a typical gene is a chain made up of thousands of links. There are four kinds of links and the sequence in which they occur "spells" the gene's message. In the preserved insects, the DNA had broken up into pieces only a few hundred links long.
Still, it was enough to identify which genes they came from and to compare the sequence with its equivalent from the same gene in a modern bee or termite.
The American Museum work on the termite, for example, has addressed an old question of how termites are related to cockroaches. The prevailing view had been that roaches evolved first and that a branch of the roach family later evolved into termites.
But the new DNA findings indicate that termites go back just as far as roaches and that the two are sister lineages that evolved from a common ancestor.
Still, Poinar suggested, "Jurassic Park is not so far away." There is amber in Alberta that contains biting midges that lived during the Cretaceous, the last period of the age of dinosaurs. They could well carry dinosaur blood, Poinar said.
"It's theoretically possible you could get dinosaur DNA from them," Poinar said. That would allow comparison with modern reptiles and birds to see where the dinosaurs fit into the evolutionary sequence. But "there would be enormous technical problems recreating a whole dinosaur," he said. For one thing, the feat has not been accomplished for extant species even with a complete, undamaged DNA sample.