Are there any genetic differences between the Spanish and Catalan populations.
The Catalan people and language.
Europe’s last Neanderthals lived in “Spain”.
The Iberian Peninsula has a lot of mountains that have facilitated regional division and the isolation of human settlement throughout history. It is the main reason why Spain is so rich in regional variations in food, culture, language and genetics.
Iberia was one of the last regions of Europe invaded by modern humans (Homo Sabiens), and therefore also one of the last strongholds of Neanderthals. After the extinction of Neanderthals and the end of the ice age, a wide range of ethnic groups settled in Iberia; among them Phoenicians, Celts, Greeks, Jews, Romans, Goths, Suebi, Franks, Arabs and Berbers. All of them have left their genetic footprint both geographically and culturally.
Celtic, Roman and Barbaric genes
The Celtic migrations to Iberia had a large impact on modern Spanish genes. Two thirds of Spanish male genes can be traced back to this period under the form of R1b (Haplogroup).
Alans, Suebi and Vandals
In 406, the Alans (Iranian origin), the Suebi and the Vandals (Baltic Sea origin) crossed the Rhine together, invading Gaul. Three years later, they crossed the Pyrenees into Roman Hispania. The Suebi migrated to the western half of Iberia, where they established the Kingdom of Gallaecia (409–585). The Vandals and the Alans went south to Andalusia. They crossed over to North Africa in 429 and founded a kingdom that included Sicily, Sardinia and Corsica.
Visigothic Kingdom
At the beginning of the 4th century, the Goths were the first to penetrate into the Roman Empire. After settling in the Balkans, they split into two factions, the Ostrogoths and the Visigoths. The Visigoths, under Alaric I, sacked Rome in 410 and established a Visigothic Kingdom in south-western Gaul in 418.
After expanding their empire into Aquitania, the Visigoths expanded south from Barcelona, and by the middle of the 5th century they had conquered most of central and southern Iberia. In the 580s they annexed the Suebi Kingdom, as well as the land of the Cantabrians and the Basques in the north. The Visigothic Kingdom lasted until the Muslim conquest of Iberia in 711.
The Visigothic and Suebi invasion did not leave a lot of Germanic DNA in the Iberian peninsula, but Galicia and Catalonia are the regions with the highest ratios of Germanic Y-DNA (approx. 5 to 10% of the male lineages).(link)
Muslims and Franks
Under the rule of Charlemagne, the Spanish March was created as a buffer against the Umayyad Caliphate on the Spanish side of the Pyrenees (from Navarre to Catalonia). The March quickly evolved into the independent Kingdom of Navarre (824–1620) and the Frankish County of Barcelona (801–1162), later to become the independent Kingdom of Aragon (1035–1706). The Franks did not, however, colonize the region and the genetic legacy would only have passed through interbreeding between nobilities which had no effect on the genetics of the wider population.
Indo-European genes
The majority of Iberian paternal lineages are of Indo-European (R1b, G2a3b1, J2b2 and a small amount of R1a), which can be traced to the Celtic invaders, and to a lower extent to later Roman and Germanic settlers. In total, these amount to 50-85% of Spanish and in Catalan Y-DNA .
As I compared the Catalan Y-DNA with other regions, I found out that the Catalan genes bear closest relation to the genes of Castile La-Mancha. Even the Valencians did not come as close. The only difference is that the Catalans, like the Basques, are the only Western Europeans completely lacking genetic contribution from Southwest Asia. (link)
The genetic brothers