Dinosaur DNA dilemma
In 1994 the prestigious journal Science shocked the scientific world by publishing sequence data from DNA retrieved from dinosaur bone said to be 80 million years old.
DNA is a fragile molecule, and so it breaks down quickly. Measurements of DNA stability suggest it could last thousands of years, at best, under the likely conditions.
But 80 million years was just too incredible for other skeptical scientists. Eventually, these skeptics were vindicated—as it became apparent that the original researchers had sequenced contaminating human DNA, not dinosaur DNA.
However, in 2012 a different group of researchers published new results supporting the discovery of actual dinosaur DNA. These new results appear much harder to disprove, with the researchers applying multiple checks against contamination from non-dinosaur sources.
The preservation of dinosaur DNA doesn’t make sense from an evolutionary perspective. But it fits biblical history, whereby dinosaurs lived thousands of years ago, not millions of years ago.