Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest — and putting paid to hopes of cloning a Tyrannosaurus rex.Now, cloning a dinosaur or other ancient species from theoretically nonexistent DNA would not be a directly conclusive debunking of evolution, but would be a sufficiently devastating blow to the evolutionary timelines as to render it every bit as temporally dubious as it appeared when its earliest advocates were worrying about how the time-consuming process could have taken place in only 6,000 years.
After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.
By comparing the specimens' ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on.
The team predicts that even in a bone at an ideal preservation temperature of −5 ºC, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.
I would be interested to hear from those who seriously subscribe to the theory of evolution and learn if, given this announcement of a 521-year DNA half-life, the successful cloning of a dinosaur known to be from a historical epoch well before the 2-million year readability limit would be enough to cause them to abandon their belief in the theory. And if not, would the discovery of rabbit fossils in the Precambrian be enough to do it?