The current population of the island of New Guinea is about eleven million. Many believe human habitation on the island dates to as early as 50,000 BC,[19] and first settlement possibly dating back to 60,000 years ago has been proposed. The island is presently populated by almost a thousand different tribal groups and a near-equivalent number of separate languages, which makes New Guinea the most linguistically diverse area in the world. Ethnologue's 14th edition lists 826 languages of Papua New Guinea and 257 languages of Irian Jaya, total 1073 languages, with 12 languages overlapping. They fall into one of two groups, the Papuan languages and the Austronesian languages.