Human Diversity in Jordan: Polymorphic Alu Insertions in General Jordanian and Bedouin Groups

Abstract

Jordan, located in the Levant region, is an area crucial for the investigation of human migration between Africa and Eurasia. However, the genetic history of Jordanians has yet to be clarified, including the origin of the Bedouins today resident in Jordan. Here, we provide new genetic data on autosomal independent markers in two Jordanian population samples (Bedouins and the general population) to begin to examine the genetic diversity inside this country and to provide new information about the genetic position of these populations in the context of the Mediterranean and Middle East area. The markers analyzed were 18 Alu polymorphic insertions characterized by their identity by descent, known ancestral state (lack of insertion), and apparent selective neutrality. The results indicate significant genetic differences between Bedouins and general Jordanians (p = 0.038). Whereas Bedouins show a close genetic proximity to North Africans, general Jordanians appear genetically more similar to other Middle East populations. In general, these data are consistent with the hypothesis that Bedouins had an important role in the peopling of Jordan and constitute the original substrate of the current population. However, migration into Jordan in recent years likely has contributed to the diversity among current Jordanian population groups.

The State of Jordan emerged in 1946 as the Hashemite Kingdom of Transjordan when Britain and France divided the Middle East after World War II. Since 1948 it has officially been known as the Hashemite Kingdom of Jordan. Jordan is a predominantly Arab nation, whose capital and largest city is Amman. It is located on the East Bank of the Jordan River and the Dead Sea and borders Palestine and Israel states to the west, Syria to the north, Saudi Arabia to the south and east, and Iraq to the northeast.

Because of its position in the Levant region, Jordan represents one of the major pathways for human movement. Since antiquity, traders traversed this area carrying products from the lands of the Indian Ocean basin to Syria, to be distributed from there to other parts of the Mediterranean world. Jordan was a crossroads for people from all over what is known today as the Middle East. Because of its strategic position connecting Asia, Africa, and Europe in the ancient world, Jordan was a major transit zone and thus an object of contention among the rival empires of ancient Persians, Macedonian Greeks, and many others (Salibi 1998).

Current inhabitants of Jordan are mostly Arab descendants of Transjordan or Palestine, and Bedouins, part of a predominantly desert-dwelling Arabian ethnic group traditionally divided into tribes. Historically, the inhabitants of this desert, which spreads northward into Syria, eastward into Iraq, and southward into Saudi Arabia, were Bedouin pastoralists (Salibi 1998). Today around 98% of the 7.9 million Jordanians are of Arab origin, along with other small minorities such as Circassians (1%) and Armenians (1%). Culturally, the official language is Arabic; in terms of religion, over 92% of the people are Sunni Muslims, around 6% are Christians (mostly Greek Orthodox, but some Greek and Roman Catholics, Syrian Orthodox, Coptic Orthodox, Armenian Orthodox, and Protestant denominations), and the remaining 2% are Shia Muslim and Druze populations (Central Intelligence Agency 2013–2014).

Historically, the term “Bedouin” has denoted both a nomadic way of life and a group identity. Bedouins were the original settlers in the Middle East. From the Arabian Peninsula, their original home, they spread out and now live in desert regions of all the countries between the Arabian Gulf and the Atlantic. The Arab conquest of North Africa in the seventh century AD caused a wide dispersion, such that today the Arab culture is extended over North Africa and beyond.

The availability of historical and ethnical information about Jordanian peoples (Salibi 1998) contrasts with the lack of information about the genetic background of these groups. As far as we know, previous genetic information about Jordanian populations includes two studies on uniparental markers analyzed in Bedouins and general Jordanians (Flores et...