The proximity of Gujaratis to Europeans "supported the existing view of European influences in the genetic composition of north Indian populations".[3] According to a 2015 study by British and Pakistani geneticists (Ayub et al., 2015), Europeans split from South Asians (represented by Gujaratis) around 8,000 years ago in the Neolithic period, as supported by LD decay. This study divided humans into five distinct clusters based on allele-frequency differences: (1) Africans, (2) a widespread group including Europeans, Middle Easterners, and South Asians, (3) East Asians, (4) Oceanians, and (5) Native Americans.[4] A 2014 study by Singaporean geneticists (Ali et al., 2014) studied the differences between two sub-populations of India, the Indo-European-speaking Gujaratis (labelled as North Indians) and the Dravidian-speaking Tamils (labelled as South Indians), and found that one of the most apparent differences between them is in skin complexion, with North Indians being much fairer, which points to gene flow from Europe to North India.[5] The study also mentions: