Well, the last thing roots in the relatively small number of settlers, their homogen ancestry in norway and the century-long isolation after colonization. The genetic pool is very small, that's why Iceland has this unique genetic database of every citizen, it's very important for DNA scientists, also because most icelandics can follow their rpots right up to the first years of settlement. Isn't there also this app in Iceland where you can check if you are related to your potential one night stand?