The Half-Life of DNA

According to an article on Nature, paleontologists at the University of Copenhagen and Murdoch University have calculated that the half-life of DNA is 521 years. This was discovered in New Zealand, where the paleontologists examined 158 leg bones of three extinct giant bird species called moa. These leg bones contained DNA and were between 600 and 8000 years old. After a cell dies, enzymes break down the nucleotides that make up DNA. Much of the break down comes simply from reactions with water. However, groundwater is considered to be found everywhere and so DNA theoretically decays at a set rate. The half-life means that half of the bonds between the nucleotides in the DNA have been broken.



The paleontologists predict that at ideal preservation conditions, DNA would be fully broken down after a maximum of 6.8 million years. What this means is that the theories of dinosaur and insect DNA being trapped inside of amber are incorrect. Dinosaur bones are relatively 65 million years old, so the chances of being able to recover dinosaur DNA and possibly use that DNA to clone them (think Jurassic Park) are far out of the question.

While this find is unfortunate in an evolutionary perspective, it is still something that could be used to help date fossils and determine when extinct creatures existed, to an extent.