Are there any genetic differences between the Spanish and Catalan populations.
The Catalan people and language.
The Catalan people live in the region called Catalonia (Catalunya), in eastern Spain. The Catalan language is a member of the Romance language family and closely related to its origins of Occitan language which is spoken mainly in southern France, and Aranese, which is the official language in Vall d’Aran (a region in the Pyrenees).
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).
In spite of Hispania being part of the Roman Empire, the Romans did not establish a lot of population colonies in Iberia. There were only few Roman cities in Hispania the biggest were: Barcino (Barcelona), Tarraco (Tarragona), Emerita Augusta (Mérida), Italica (Santiponce, Seville), and Carthago Nova (Cartagena).
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.
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.
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
The Catalan paternal genetic lineages are Indo-European, and their closest genetic brothers are living in Castile Le Mancha. On the other hand, Spain is one the oldest countries in continuous existence in Europe. This long political unity has until the recent decades favored Spanish people to marry between Spanish (Catalans included).
The idea of Catalan race
The idea of Catalan race was first raised in the 19th century and it seems that this Catalan imperialism still exists. One good example of radical Catalan ideas was written by Daniel Cardona i Civit (1890-1943), a comrade of Francesc Macià. “It is necessary that the Catalan woman becomes our first patriotic duty, by not loving any natural enemy of her Motherland. For a Catalan woman only a Catalan husband!”(more here).
So, the conclusion is that Catalans including other Spaniards and even Portuguese are the same ethnic people. The argument that the Catalans and Spanish are a different race is just bullshit. We shouldn’t mix nationalistic ideas with genetics, because Spain has a long and dark history of racial conflicts.