Strong religious beliefs have been part of Iranians' lives for thousands of years.
Almost all Iranians are Muslim, or followers of Islam. Iran has a long history of scholarship that has created a rich culture of art, literature, poetry, music, cuisine, and architecture.
It is the only country with both a Caspian Sea and an Indian Ocean coastline.
Iran made major contributions to the Islamic Golden Age that followed, producing many influential figures in art and science.
"A different way to look at is it's almost impossible for evolution not to happen." Still, the findings also are controversial, because it's far from clear what effect the genetic changes had or if they arose when Lahn's "molecular clock" suggests — at roughly the same time period as some cultural achievements, including written language and the development of cities.
Lahn and colleagues examined two genes, named microcephalin and ASPM, that are connected to brain size.
The history of Iran, commonly also known as Persia in the Western world, is intertwined with the history of a larger region, also to an extent known as Greater Iran, comprising the area from Anatolia, the Bosphorus, and Egypt in the west to the borders of Ancient India and the Syr Darya in the east, and from the Caucasus and the Eurasian Steppe in the north to the Persian Gulf and the Gulf of Oman in the south.
Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 7000 BC.