DNA breaks aside with time, so the older it’s, the smaller the items grow to be—till there’s nothing left to detect. And the shorter the fragments are, the trickier it’s to assign them to a selected teams of crops or animals.
“The huge damage pattern made it very clear it was ancient DNA,” says Willerslev, who says he and his colleagues started working with the Greenland samples in 2006. “When it’s 2 million years, there has been so much evolutionary time, that whatever [species] you are finding are not necessarily very similar to what you see today.”
The Danish workforce says the DNA they discovered was preserved by freezing temperatures and since it was sure to clay and quartz, which additionally slows down the method of degradation.
Exactly how far again in time researchers will be capable of see stays an open query. “Probably we are close to the limit, but who knows,” says Tyler Murchie, a postdoctoral fellow at McMaster University who develops strategies for learning historical DNA. He notes that the Dutch researchers have been profitable in combining a number of strategies to “create a robust reconstruction of this ecosystem.”
Willerslev as soon as predicted it could be inconceivable to recuperate DNA from something that lived greater than one million years in the past. Now that he’s damaged the document, he’s reluctant to say the place the restrict lies. “I wouldn’t be surprised if…we could go back twice as far,” he says. “But I wouldn’t guarantee it.”