I am Croatian, and I have been dealing with this issue for a long time. First, I must say that Croats are 180.5 cm on average, but the average for Croats is broken by northern Croats, where haplogroup R1a predominates. If you were to look only at the region of Dalmatia and Slavonia, the Croats would be the tallest nation in the world, because the concentration of the tallest people in the world is in the area of Dalmatia, and then in Herzegovina in the parts of western Herzegovina where the Croatian population predominates. The city of Makarska in Croatia has an average height of 187 cm. Seen this way, Croats are taller than Montenegrins and Bosniaks.
The reason for this height lies in eating habits with a combination of mountains and a favorable climate. Peoples who are herders, who are engaged in sheep and goat breeding, are usually tall, as an example of this we have the Masai and Nilotic people. These are two noble peoples who have always been engaged in animal husbandry. Animal husbandry has existed for thousands of years in the Western Balkans. Western Dinars have always fed on dairy products, cheese and milk. They also ate fish, so our diet was rich in protein. Another reason is the extreme climate in the Western Dinarides, a combination of very cold and harsh winters, and intense heat with full sun in the summer. Western Dinars are also known for their large feet, the largest in the world, and the reason for this lies in their genetic adaptation to rugged mountains that are very difficult to move. These are all the reasons why the Western Dinars are so tall and rugged. The reason also lies in the hard physical life, the cultivation of the land which is full of karst and stones, the movement and keeping of the cattle on the difficult craggy mountain slopes. The life of the Western Dinars has always been very difficult and physically demanding, which is why the diet had to be rich in proteins. Some say that the reason for such height is also in our famous Dalmatian prosciutto. Prosciutto is rich in proteins.
The ideal combination of diet, Mediterranean climate and mountains are the reason for such a high altitude.
There are also theories that Croats are descendants of Illyrians or indigenous Balkan peoples who were originally descendants of the Nephilim who fled to the Western Balkans from the Greeks. Many Croatian historians and archaeologists talked about the fact that graves of people who were 2.5 to 3 meters high were found in Dalmatia and Herzegovina.
I am not sure that haplogroup I2a1b has a direct relationship with altitude, I think that it is influenced by the Western Dinarids. If any haplogroup came to the Western Dinarides and lived the way of life that is lived here, it would grow in several generations. I'm sure of that. The Slavs who came to the Western Dinarides are taller than all the other Slavs of Eastern Europe. The Western Dinarids influenced the Slavs to grow taller than their neighbors to the east and north.
