In the movie "Jurassic Park," the recovery of an ancient mosquito which had become trapped in tree resin (amber) shortly after feeding on a dinosaur led to the creation of a dinosaur park where dinosaurs again roamed. Is this idea only based in fantasy, or is it possible that scientists could indeed clone dinosaurs?
Cloning is the act of creating an identical copy of an organism. In "Jurassic Park," the type of cloning featured is reproductive cloning which is similar to "in vitro" fertilization. However, it is much more complicated as genetic material must be implanted in the egg rather than using a sperm to fertilize the egg.
In order to clone dinosaurs, scientists would need to obtain dinosaur DNA (deoxyribonucleic acid), and scientists currently feel that the best source for this would indeed be a female mosquito who had gorged herself on dinosaur blood before landing in tree resin. Since finding fossils in amber is a rarity, it follows that this scenario would be a rarity, but not an impossibility. Another possible source of dinosaur DNA is dinosaur skeletons. (In March 2005, a group os scientists, while examining a Tyrannosaurus Rex, found preserved soft tissue).
Some scientists say that it is unlikely that a dinosaur will ever be cloned. Although bone marrow and blood are the best parts of an animal from which to extract DNA, they feel it is unlikely that they would survive fossilization and that freezing and thawing would most likely break up the DNA. This could be a problem as an entire sequence of DNA is needed, not just a tiny strand. There is also the possibility that the DNA would have become contaminated with the mosquito's own DNA. Furthermore, since scientists would not know what animals the mosquito had sampled, they question how they would be able to identify the DNA.
There are other scientists, however, who believe that it may indeed be feasible to clone dinosaurs. Blood that contains hexapods and chelicerates that has become embedded in amber may be a good source of DNA. Amber is an excellent preservative because it dries almost immediately when released and actually has the potential to preserve the entire insect including digestive tract and intestines. Amber also may help prevent the decomposition of insects that become embedded due to its antiseptic properties. It would be important, of course, that the amber was from the Jurassic and Cretaceous eras.
Of course any gaps in the dinosaur DNA must be filled in (remember in "Jurassic Park" they used frog DNA). There is a possibility that the gaps could be filled in by using the dinosaur's own genetic code if the mosquito had eaten more than one of the dinosaur's cells (which of course is probable). In this instance, all the DNA strands could be sequenced, and since all are probably not damaged in the same place, it may be possible to create a computer program which would, by analyzing the strands, be able to notify scientists as to what should be in the gaps.
At this date, it is unlikely that scientists have all of the tools needed to clone dinosaurs. However, it is a possibility that in the future, with new technology and new scientific discoveries, cloning a dinosaur will become a reality. There are many facts that lead scientists to feel this could happen, among them the fact that DNA is an extremely tough molecule, amber is an excellent preservative and DNA millions of years old from insects and other animals has indeed been restructured.
"Jurassic Park" may be closer than we think!