Negritos are considered among the earliest inhabitants of the islands. These minority aboriginal settlers are an Australoid group and are a left-over from the first human migration out of Africa to Australia, and were likely displaced by later waves of migration. At least some Negritos in the Philippines have Denisovan admixture in their genomes. Ethnic Filipinos generally belong to several Southeast Asian ethnic groups classified linguistically as part of the Austronesian or Malayo-Polynesian speaking people. There is some uncertainty over the origin of this Austronesian speaking population, with it being likely that ancestors related to Taiwanese aborigines brought their language and mixed with existing populations in the area. European DNA is present in many Filipinos today. A craniometric study reveals that samples taken from graveyards across the Philippines show a mean ratio of European descent of circa 6%. Under Spanish rule there was also immigration from elsewhere in the empire, especially from Latin America.