Marker 2
The pine trees look different from one side of the path to the other. At the upper limit of Europe's mountain forests grows a “prostrate” pine called creeping pine. To ascertain whether its shape – which is different from the mountain pine's – was due to violent winds or genetics, Flahault planted the two trees next to each other. He was thus proved that this particularity was due to genetics, and that these are indeed two different species. In complete contrast with the original conditions, the creeping pine is now dominated by the other trees and poised to disappear.