 The precise reasons for this unusual diversity have not yet been conclusively determined, but Amazonian languages seem to have had fewer than 10,000 native speakers even before the invasion of European colonists wrought havoc on the societies by which they were spoken.Despite the large-scale diversity, the long-term contact among many of the languages of Greater Amazonia has created similarities between many neighboring languages that are not genetically related.Most indigenous Amazonian people today are bilingual or even monolingual in Spanish or Portuguese, and many Amazonian languages are endangered as a result.