Between Showers

Why we can’t clone dinosaurs from mosquito blood

Scientists have argued that much of the Jurassic Park’s (both book and film) content is impossible for various reasons, most notably the suggested means of recovering dinosaur DNA from mosquitoes trapped in fossilized tree sap. While this theory is largely a plot device by Michael Crichton (the author), both novel and movie sparked debate on the feasibility of cloning dinosaurs.

Three arguments why it would not be possible to obtain dinosaurs with this process are summarized thus:

1. Dinosaur DNA would be very difficult to correctly sequence without a complete, intact DNA strand for comparison. It would be unlikely to find a complete sequence because DNA is typically unstable outside living organisms (unless it is in the proper buffer).
2. Any gaps in the resulting DNA sequence must be filled with dinosaur DNA; using frog DNA as the story suggests would likely produce an organism that varied from the original animal.
3. In order to clone a complete DNA sequence, an oocyte from the same organism is required. Since no Mesozoic dinosaurs are alive today, this would be impossible.

Furthermore, it is likely that any prehistoric DNA obtained from a fossilized mosquito would have become contaminated with the mosquito’s own, again making it problematic to clone an ‘accurate’ and viable organism.

A theme expressed throughout the story and its sequel is that of homeothermic (warm-blooded) dinosaurs, a then-recent theory popularized by paleontologist Bob Bakker. While the cinematic adaptation of Jurassic Park used ostrich eggs as vessels to facilitate expression, the novel described “a new plastic with the characteristics of an avian eggshell.” The plastic was called ‘millipore’, invented by an eponymous company subsequently bought by InGen (Millipore Corporation is also the name of a real company that manufactures materials for use in biological sciences, although they are not known to make dinosaur eggshells).

Another note, most of the dinosaurs featured in the novel are not from the Jurassic period; they are actually from the Cretaceous period, the last period during which non-avian dinosaurs lived. However, this may be chalked up to an ignorant or naive marketing decision on InGen’s part.