Jurassic Park: Fact or Fiction?

Although it’s fun to fantasize about dinosaurs in a modern zoo--being able to touch them and hear them and watch them--cloning dinosaurs from prehistoric DNA trapped in petrified insects is, unfortunately, impossible, for several reasons.

To begin with, it’s extremely difficult to find DNA from prehistoric times, even if it was trapped in a bug inside amber. Even if the insect died immediately after sucking dinosaur blood, the stomach acid would keep digesting the food with the DNA in it. DNA is very fragile when exposed to the air (the oxygen damages it; it’s even hard to keep DNA together in a laboratory, let alone a 160 million year old insect!). Of course, finding ancient DNA isn’t impossible; paleontologist Jack Horner has found some.

Prehistoric DNA is a novelty, though--nothing can be done with it, scientifically. The largest quantity found so far is a sequence of merely 250 base pairs which is nothing compared to the 1 - 10 billion it takes to make a single organism. Besides, scientists have no clue as to what dinosaur DNA should look like; yes, they know it’s made of the same material as all other DNA, but the exact sequence isn’t known, and the sequence is everything, when it comes to cloning. That means that scientists couldn’t add known DNA sequences (say from another reptile or bird) to make a full strand, either.

The DNA isn’t the only problem, though: one also has to consider things such as food and environment. If a dinosaur ever were to be cloned, zookeepers would have no way to feed the herbivores (plant eaters; it has been suggested that the meat-eating dinosaurs would have no problem because the chemical composition of meat probably hasn’t changed much). Plants constantly develop poisons and other protective measures to prevent being eaten. Dinosaurs wouldn’t be able to adapt (whereas modern animals have been able to over the past millions of years, dinosaurs have not because they’ve been extinct) to these threats and would die after the first meal. The biggest threat to a newly cloned dinosaur, however, would be disease. Since the last dinosaur died 65 million years ago, bacteria and viruses have changed drastically; an infected dinosaur would have no means of defense against any modern microbes.

These are just the main reasons why scientists can’t clone dinosaurs, but the list goes on and on. For now, dinosaurs will simply have to be content with remaining in our imaginations.

Posted by permission Mark Parisi