India's Muslim communities, it was again found that the Muslim population was overwhelmingly similar to the local non-Muslims associated, with some having minor but still detectable levels of gene flow from outside, primarily from Iran and Central Asia, rather than directly from the Arabian peninsula. A research regarding the comparison of Y chromosomes of Indian Muslims with other Indian groups was published in 2005. In this study 124 Sunnis and 154 Shias of Uttar Pradesh were randomly selected for their genetic evaluation. Other than Muslims, Hindu higher and middle caste group members were also selected for the genetic analysis. Out of 1021 samples in this study, only 17 samples showed E haplogroup and all of them were Shias. The very minor increased frequency however, does place these Shias, solely with regards to their haplogroups, closer to Iraqis, Turks and Palestinians. Early history of Islam in India Trade relations have existed between Arabia and the Indian subcontinent since ancient times. Even in the pre-Islamic era, Arab traders used to visit the Konkan-Gujarat coast and Malabar Coast, which linked them with the ports of Southeast Asia. Newly Islamised Arabs were Islam's first contact with India. Historians Elliot and Dowson say in their book The History of India, as Told by Its Own Historians, that the first ship bearing Muslim travellers was seen on the Indian coast as early as 630 CE. H.G. Rawlinson in his book Ancient and Medieval History of India claims that the first Arab Muslims settled on the Indian coast in the last part of the 7th century CE. (Zainuddin Makhdoom II "Tuhafat Ul Mujahideen" is also a reliable work.) This fact is corroborated by J. Sturrock in his Madras District Manuals and by Haridas Bhattacharya in Cultural Heritage of India Vol. IV. It was with the advent of Islam that the Arabs became a prominent cultural force in the world. Arab merchants and traders became the carriers of the new religion and they propagated it wherever they went. According to popular tradition, Islam was brought to Lakshadweep islands, situated just to the west of Malabar Coast, by Ubaidullah in 661 CE. His grave is believed to be located on the island of Andrott. A few Umayyad (661–750 CE) coins were discovered from Kothamangalam in the eastern part of Ernakulam district, Kerala. According to Kerala Muslim tradition, the Masjid Zeenath Baksh at Mangalore is one of the oldest mosques