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The Ecphora QUARTERLY NEWSLETTER OF THE CALVERT MARINE MUSEUM FOSSIL CLUB Volume 13, Number 1 Winter 1997 Whole Number 43 Reprinted from The Australian MagazineJuly 24-25 1993. COULD IT HAPPEN? Films in which scientists re-create dinosaurs by extracting DNA molecules fromfossilised remains and 'growing'them are not as fantastic as we might suppose. By Nigel Hawkes "I'll be damned!" says a breakfasting on passing jeeps. character in Michael Crichton's Gripping stuff, the book also novel Jurassic Park. "That might displays an up-to-the-minute just work." As it launches a knowledge of DNA, based on -------. publicity blitz of brontosaurian Crichton's friendship with .one of proportions to plug Steven the pioneers of a new field of Spielberg's film, Universal Pictures science, which we might call is echoing the sentiment. IfJurassic palaeogenetics. Park the movie can be·turned into a George Poinar, professor of hit by the sheer volume of entomology at the University of associated merchandise, they are California, has extracted DNAfrom home free - in the US alone more a bee preserved in amber for 40 than 100 companies have been lined million years. The bee was trapped up to sell 1000 products .associated on a conifer tree by sap flowingover with the film. The 'selling' of the it - killing it and sealing it from the film will be no less intensive in air, so preventing decay. In Jurassic Australia and elsewhere in the Park, the DNAcomes not from a bee world. but from a blood-suckinginsect that The power of the book, had recently feasted on the ample however, rests not on puff but flanks of a dinosaur. Preserved plausibility. Like most of the best inside the insect is the dinosaur's science fiction, it hovers on the very blood, from which the DNA is edge of science fact, creating a extracted to re-create the creature. nightmare out of the kind of gentle Ten years ago, the idea of speculation that scientists enjoy. finding ~ny traces of DNA in The plot hinges around a rich and specimens as old as this would have secretive tycoon who sets our tore• been considered iWpossible. True, create the dinosaurs, using all the there were extinct creatures such as latest tools of genetic analysis and the hairy mammoth preserved deep• manipulation. It all goes wildly frozen in the icy Siberian tundra wrong in the end, as the beasts take from which biological molecules over the reserve and start might be extracted, but fossilised :\. remains were assumed to be, ripped into shreds and written in a ". literally, stone dead. language you barely comprehend, In 1984 a group at the and having to reassemble it in the University of California successfully dark, without using your hands. extracted DNAfrom the skin of the About four million fragments would quagga, a relation of the zebra have to be a~sembled in the right which disappeared last century. order, without actually knowing Next came DNA from a Egyptian preciselywhat that order was: a very mummy 2400 years old and, at tall order indeed. Oxford, from a human bone 5500 years old. In Jurassic Park, Crichton But the calendar really began simplifiesthe problem by leaving his to stretch with the development of a dinosaur-builders to concentrate DNAamplification technique called only on those sections of DNAthat polymerise chain reaction (PCR). differ from those of surviving The method allowed even the tiniest species. This reduces the problem traces of DNA- a single molecule, in significantly because large stretches principle - to be multiplied a of the genome are identical. millionfold. The arrival of PCR Humans and chimpanzees, for meant that even it picograms of example, share 98.4 per cent of their DNA had survived, they could be DNA. So if it were possible to extracted and copied. Pretty soon, program a computer to analyse the scientists had isolated DNA from DNA and locate the few per cent magnolia leaves 18 million years that differ from species to species, old, from Poinar's bee and from a the task would be more manageable. termite, also preserved in amber, of So far, the tools for doing this in about the same vintage. fact, as opposed to fiction, are Some of the claims have been nowhere in sight. contested, and great care is needed A further difficultyarises from if the PCRmachine is not to amplify the fact that most DNAdetected some useless fragment of DNAsuch from ancient remains does not come as a trace of human sweat. Oxford from the nucleus of the cell, but molecular biologist Bryan Sykes from tiny objects called found that at least a third of the mitochondria, .This from of DNAis samples they tested were the result at least 1000 times more plentiful of accidental contamination. than nuclear DNA,but it would be That said, it is now accepted useless for reconstructing extinct that DNAcan survive in some very species. Only the nuclear DNA unexpected places, and this provides carries the creature's blueprint. the jumping-off point for Jurassic Mitochondrial DNA is useful for Park. There are a lot of problems, tracing lineages - it is being used to however, not least the fantastic identify bones that may be those of scale of the genetic blueprint, or the last tsar of Russia - and formed genome, of any living thing. The the basis of the theory that we are scraps of DNA recovered so far all descended from a single consist of only a few hundred of the "ancestral Eve", but for re-creating 'base pairs' that are the chemical lost species it is of no use. For letters of the genetic alphabet. Yet that, the much less plentiful the whole book consists of more genomic DNA would be needed, than three billion base pairs. .increasing the difficulty of the Reconstructing the genome of operation. Higuchi, who has an extinct creature would be an isolated mammoth DNAputs it this enormous task - one compared, by way: "Theamount of mammoth DNA molecular geneticist Russell is enough so that in theory a Higuchi, to finding an encyclopaedia dedicated graduate student could - -reassemble the entire mitochondrial for DNAanalysis. The bad news was genome. So we could have that the quagga was not more than elephants walking around canying a colour variation of the zebra and mammoth mitochondrial DNA not a distinct species. The good sequences. But it would make news was that this meant it could absolutely no difference- theytd still be reconstructed, although slowly. be elephants. It "Oncea species is. extinct it is Even if we could capture some gone forever, like the dodo," Rau of the right sort of DNA and says. "A subspecies is a different reconstruct a complete dinosaur story." The quagga genes were not genome, the problem would not be irretrievably lost, he said, but were solved. In spite of all that has been scattered among the plains zebra. learnt about genes, there is still In 1987, with nine selected ignorance over what it takes to animals, the scientists started a persuade a cell to behave breeding program to try to retrieve embryonically - that is, to develop the quagga genes. Eric Harley, into a complete organism. This professor of chemical pathology at difficulty is overlooked in Jurassic the University of Cape Town, said Park, but might well turn out to be the first foals "look quite good", but at least as great as all the others. that it may take 20 years to So is the analysis of DNAany good "retrieve"a quagga. There is irony at all in reconstructing lost species? in the fact that the only species that Maybe, although the only success so DNA analysis has helped to far comes in a species that turns reconstruct is not a species at all, out not to be a species at all, the but Poinar is undeterred. Later this quagga. year he is planning an expedition to The last quagga died in 1883 a rich source of amber in Alberta, in Amsterdam Zoo. Thousands, Canada, which is believed to be full perhaps millions, had been ofmidges - "and one of them is very exterminated in South Africa qy likelyto have bitten a dinosaur". hunters, leaving only -23 stuffed That in itself would be a specimens, seven skeletons and fantastic find, because analysis of some illustrations. Zoologists have the DNAmight help to provide clues never been sure whether the quagga about the dinosaurs. Since answers was a species of its own or merely to questions about these creatures another member of the zebra family. have proved elusive for decades, Reinhold Rau, of the South Mrican providing them would be a great Museum, collecteddry muscle tissue breakthrough: not quite as and blood from skins of four stuffed sensational as Jurassic Park, but specimens and sent them to the US remarkable enough. If you would like to submit an article to be included in the Ecphora please send it by May 1, 1997 to: Calvert Marine Museum Fossil Club P.O. Box 321 Sykesville,MD21784 The Calvert Marine Museum Fossil Club (CMMFC)is a non-profit organization. The Ecphora is the quarterly newsletter published by the CMMFC. The purpose of this newsletter is to provide better communication and to share information that may be of interest to the members of CMMFC.Articles which appear in the Ecphora are unedited and are published as submitted. Unless otherwise stated, articles published in the Ecphora are the views and opinions of the individual authors and do not necessarily reflect the views or the responsibility of the Calvert Marine Museum or the CMMFC. MUSEUM NEWS The shark skeleton is hanging and the Miocene beach beckons---we are now in the exciting home stretch of getting the museum's new f-ossilexhibit "TREASURE FROM THE CLIFFS -- Exploring Marine Fossils" ready for the March 22nd opening.

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