which brings my mind to how varied a 300 000 gene pool can possibly be.
You know, that's the first thing I thought of when you mentioned the population of Iceland.
yup, and hint #2 is that they still speak ancient norse :b its all a big "pride" thing, but nobody stops to think "hey... norwegians and swedes also spoke old nordic, but people coming and going, influx from elsewhere slowly changed the language, as everywhere on the planet, except jungle tribes"
(hell even jungle tribes make sure to shift around, to avoid stagnation)
ah well, i guess theyre happy tho