Well this might put a crimp in Steven Spielberg's plans to make "Jurassic Park IV." A team of scientists in Australia and New Zealand has concluded that cloning dinosaurs just isn't possible because DNA would not be viable after millions of years.
In a paper published October 10 in the journal Proceedings of the Royal Society B, the scientists reveal that DNA has a half-life of 521 years. That means that even fossilized or carefully preserved DNA would break down half way in a little over five centuries, then another half every 521 years.
When you consider the dinosaurs went extinct about 65 million years ago, this means there's no way that enough DNA could ever be collected to bring a dinosaur back to life.
The scientists — from Murdoch University, the University of Canterbury and other universities and organizations — studied the mitochondrial DNA of 158 fossilized bones from three species of moa, the massive, flightless New Zealand birds that went extinct centuries ago. The fossils had all been radiocarbon-dated and were shown to be between 6,000 and 8,000 years old.
Based on the degradation of the DNA samples within these moa fossils, the scientists concluded that DNA would completely break down in 6.8 million years at an absolute maximum, and that's only when it was stored at optimum conditions. (As in real estate, the location of fossils does matter. DNA breaks down at different rates based on temperature, water, and levels of microbes.) Even DNA slightly younger wouldn't be very useful for cloning: they found that DNA would break down to a point where it was completely unreadable in about 1.5 million years.
Now, the purpose of this new paper isn't really to say if dinosaurs can be cloned or not. The team's real objective was to, as they wrote in the paper's abstract, "provide a baseline for predicting long-term DNA survival in bone." But it does support those scientists who say that dinosaur cloning can't be done. Simon Ho, a computational evolutionary biologist and senior lecturer at the University of Sydney, who was not affiliated with this study, told Nature that the paper "confirms the widely held suspicion that claims of DNA from dinosaurs and ancient insects trapped in amber are incorrect."
So it doesn't look like dinosaurs could really be cloned using old DNA, but what about other extinct species? In a recent "Big Think" video, theoretical physicist and TV-science-program mainstay Michio Kaku says we could resurrect much more recently extinct species, such as wooly mammoths or even Neanderthals. He also suggests that dinosaur DNA might still exist — not in fossils, but in the genes of modern chickens and other creatures. Does that means dinosaurs could be resurrected through some form of future gene therapy? Only time and Steven Spielberg known for sure.
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