I was reading this Wikipedia article about the genetic history of Italy, and I found it interesting.
There are however a few things that puzzle me, because they seem to contradict each other. For example it states that because of the Alps forming a natural barrier Italy is, along with Finland, a genetic island in Europe. Does this mean Italians and Finns are genetically separated from all other Europeans, and to what extent? Later in the same article it says that "In Italy as elsewhere in Europe the most common haplogroup is haplogroup H", which would seem to contradict the genetic island theory. After all, Italy has been colonized by countless populations throughout its history, which might suggest the Alps didn't really stop the gene flow from neighboring countries (not to mention that other European countries are equally separated by mountains, like Spain).
I have no background in genetics whatsoever, so excuse my ignorance, I'm just trying to understand an article that seems very confusing and throws lots of different information together.
EDIT: Thanks for the quick reply! I've found another link (which seems to be more reliable than Wikipedia's unverified claim), though it still sounds like a weird theory to me.