You can analyze human genomes and match the parts that are more similar to each other than to other populations.
Ex: Someone from India might tend to have a C at a particular site while someone from China has an A. These patterns can be represented by color coded components.
https://i.imgur.com/dLHp9cT.png
What science has found over and over again for the last 25 years, is that modern Europeans are only about 50% European on average.
10,000 years ago: Europe inhabited by "pure" hunter gatherers. We call these Native Euros.
8,000 years ago: Farmers from Anatolia start migrating to Europe. They are genetically distinct, and are more similar to people from Iran/Arabia.
4,000 years ago: Aryan pastoralists invade Europe in a Spanish-American style colonization event. They displace and/or violently kill all males and take their women as wives. Genetically, the Aryans in this region were a two way mix of Iranian and European.
Both the Anatolian ancestry and the Iranian ancestry portion of the Aryans come from the Middle East. What's more, they are both more genetically related to each other than they are to the European ancestry component.
ziq wrote
Since race has no scientific basis I'm not sure what the relevance of this is? Whiteness is an artificial construct like all class divisions: invented to bestow privilege to the dominant social class.