Anatolian diagonal

The Anatolian diagonal is a theoretical dividing line which runs diagonally across central and eastern Turkey from the northeastern corner of the Mediterranean Sea to the southeastern corner of the Black Sea, and roughly cuts across part of the course of the upper Euphrates River within Turkey's borders.

However, Davis considered that there were no physical, geological or climatic differences or change in soil type that could account for the phenomenon.

[2] In 1989, the Turkish botanists T. Ekim and A. Güner examined the distribution of species by detailed study of the Flora of Turkey, eight volumes of which had been published by then.

They concluded that the ecological differences between the two sides of the diagonal were of greater significance than the palaeo-geological history of the area.

[1] The Irano-Anatolian region is a significant biodiversity hotspot in the Near East and Anatolia is the transition point between the European and Turko-Iranian floras.