One afternoon, a young Eske Willerslev looked out the window. He was doing his master’s thesis, and he and fellow student Anders Hansen had been unable to get a hold of any rare, valuable old bones and now had to find other material for the DNA analyses they wanted to do as part of their project.
And fortunately for us. Because if he hadn’t been looking out the window, Eske probably would not have noticed a woman who was walking her dog and failed to pick up the dog poo.
“There is DNA in everything. Dead leaves, dog poo, the soil. So I asked myself: What happens to the DNA? Is there a chance that it remains in the soil?” says Eske Willerslev, now a professor at the Globe Institute at the University of Copenhagen.
At the time, the idea was revolutionary, but Eske Willerslev kept at it and eventually discovered that both present-day and ancient plant and animal DNA can in fact be extracted directly from the soil. This led to one of his major scientific breakthroughs as well as the establishment of an entire new research field – environmental DNA or eDNA.
“Today, eDNA is an acknowledged research field, and therefore, data is cheaper and easier to collect and more sensitive and far more standardised. This means that the data is comparable, and this helps us monitor the Earth’s biodiversity,” he says.
DNA from an entire ecosystem
Using no more than a couple of grams of soil or a small water sample, the method enables researchers to extract present-day as well as ancient DNA from an entire ecosystem – that is, anything from bacteria and fungi to animals and plants – without having access to visible remains of e.g. the animals and plants.
![[Translate to English:] Eske Willerslev](/fileadmin/_processed_/2/2/csm_Eske_Willerslev_2_gram_jordpng_71ffdbc5a9.png)
