Evidence showing that Italians have remained the same since ancient times, and not mixed with Africans, Arabs or other non-Europeans, and that they're genetically and phenotypically Caucasoid and Southern European from North to South.
Badly done studies have overestimated African admixture in Italy, but based on a large set of DNA markers, Italians have less African admixture (orange) than Northern Europeans have Asian admixture (pink).
The Moors were Arab-Berber Caucasoids, not black as is often claimed, and Italians only have a tiny amount of recent Middle Eastern/North African admixture, because the Moors were expelled from Italy.
Italians remain genetically similar to other Europeans, and unmixed with Arabs or Africans, because the Mediterranean Sea has been a strong genetic barrier (thick red lines) since ancient times.
Ancient Romans from both before and after the empire (dark blue and yellow dots) cluster genetically with Modern Italians and Southern Europeans, showing strong continuity since the Iron Age.
North-South genetic distance in Italy is about the same as in Germany, and is a product of geographic distance and the clinal distribution of Mesolithic hunter, Neolithic farmer and Indo-European ancestry.
Northern and Southern Italians cluster in-between Southwestern (Spanish) and Southeastern (Greek) Europeans, just like on the map, and not with Northern Europeans or non-Europeans.
Based on the distribution of nonmetric cranial traits, Italians (highlighted) plot in the center of a European cluster (red) that also includes Caucasoid North Africans but is far from Sub-Saharan Africans (green).
Despite some bizarre claims of big phenotypic differences between North and South, very similar sub-racial types predominate throughout Italy, and none of them are Nordic or particularly light or dark.