to a study released in 2014, the genetic diversity among some Sardinian individuals from different regions of the island is between 7 and 30 times higher than the one found among other European ethnicities living thousands kilometers away from each other, like Spaniards and Romanians. A similar phenomenon is commonly found in other isolated populations, like the Ladin groups from the Italian region of Veneto and in the Alpine area, where the local orography did not facilitate intraregional communications. However, despite a high degree of interindividual genetic differentiation being detected on multiple occasions, other studies have also stated that such variability does not occur among the main macro-regions of the island: a Sardinian region like the Barbagia has been proven not to be significantly different from the regions on the coast, like the area of Cagliari and Oristano. A study by Contu et al. (2008) found a relatively high degree of genetic homogeneity between Sardinian individuals from three different regions of the island: the northernmost area (Tempio, Gallura), a central zone (Sorgono, Barbagia of Mandrolisai) and the southernmost area (Cagliari, Campidano). Other studies have suggested again a certain degree of homogeneity within the Sardinian population. The 2015 SardiNIA study showed, by using the FST differentiation statistic, a clear genetic differentiation between Sardinians (whole genome sequence of 2120 individuals from across the island and especially the Lanusei valley) and populations from the Italian peninsula (1000 genomes), and reported an even more significant amount of difference between the Sardinians from the above-mentioned Lanusei valley (in the mountainous Barbagia region) and the other European populations. This pattern of differentiation is also evident in the lengths for haplotypes surrounding rare variants loci, with a similar haplotype length for Sardinian populations and shorter length for populations with low grade of common ancestry. Y-DNA and mtDNA studies The most common Y-DNA haplogroups among the Sardinian males, comprising ~70% of the population, are, in descending order, I2 (particularly I2a1a-M26), R1b-M269 and G2a. They are found respectively in the Western Hunter-Gatherers, Western Steppe Herders, and Early European Farmers. As in the rest of Europe, the most common mitochondrial DNA haplogroup is H. Notable Sardinians Gallery See also List of Sardinians Sardinia History of Sardinia Nuragic civilization List of Nuragic tribes Sardinian language Sassarese Gallurese Sardinian surnames Corsican people Italian people Spanish people References . Notes Romance peoples Ethnic groups in Italy