Also, it is important to note that while genetic distance is often heavily correlated to geographical distance, genetic barriers can be created by substantial geographical barriers which limit gene flow and cause breeding isolation. In Europe the Alps represent such a genetic barrier and it is not surprising that this study confirms that.
"Barrier analysis revealed genetic barriers between Finland, Italy and other countries, as has been described before [12]. Interestingly, barriers could be demonstrated within Finland (between Helsinki and Kuusamo) and Italy (between northern and southern part). Another barrier emerged between the Eastern Baltic region and Sweden, but not between the Eastern Baltic region and Poland (Figure S4). The barrier between Bulgaria and Western Russia, Poland and Lithuania may have arisen due to the fact that several populations are missing in between those countries"
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0005472#pone.0005472.s009
http://www.forumbiodiversity.com/showthread.php/31431-Northern-Italians-are-biologically-SOUTHERN-European
"Barrier analysis revealed genetic barriers between Finland, Italy and other countries, as has been described before [12]. Interestingly, barriers could be demonstrated within Finland (between Helsinki and Kuusamo) and Italy (between northern and southern part). Another barrier emerged between the Eastern Baltic region and Sweden, but not between the Eastern Baltic region and Poland (Figure S4). The barrier between Bulgaria and Western Russia, Poland and Lithuania may have arisen due to the fact that several populations are missing in between those countries"
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0005472#pone.0005472.s009
http://www.forumbiodiversity.com/showthread.php/31431-Northern-Italians-are-biologically-SOUTHERN-European
