The mosquito drank the blood of a dinosaur. It landed on a tree and got stuck in the tree's sap. Millions of year's later, the sap has fossilized into a piece of amber with the still intact mosquito locked deep inside. Scientists extract the dinosaur blood from the stomach of the mosquito. DNA from the blood is used to clone a dinosaur. A baby T-Rex is hatched in a lab. A very unique amusement park has another attraction. Or so theorized best-selling author Michael Crichton in the novel, Jurassic Park.
Michael Crichton has said in interviews that when he originally had the idea about a novel where dinosaurs were cloned in the modern day, he visited MIT and ran it by some scientists there. Could it be done? Potentially, they replied. He was surprised. Two best-selling novels and three blockbuster movies later, the question is still being debated. Could man bring dinosaurs back to earth?
The consensus seems to be that "no", the technology has not advanced enough at this time. This website from Cal Berkeley lays out the case against the possibility. Basically it comes down to this, DNA degrades over time and it is unlikely that we would ever find a useable sample of dinosaur DNA that could be both extracted and sequenced. And even if that hurdle could be overcome, the dinosaur genome would have to be assembled into chromosomes and those chromosomes would have to be implanted into a compatible living egg. And since we don't have any living dinosaurs ... no eggs, no cloning.
These facts however are not stopping a team of scientists at Penn State, who are currently working on a project to fully sequence the Wooly Mammoth genome. In 2007, a fully intact baby wooly mammoth was found in the frozen tundra of the Artic which has helped advance their work greatly. So what do they need to be able to do in order to clone a Mammoth? Will let this quirky scientist from Penn State explain it:
So will we have Wooly Mammoths roaming the earth again someday? How about a Brachiosaurus? We have no doubt the technology will one day be there. But then we'd advise the scientists to spend a little time studying Jurassic Park ... in the words of Ian Malcolm "Your scientists were so preoccupied with whether or not they could they didn't stop to think if they should."