Answer:
There are still 350 isolated indigenous groups in the Amazon.
Step-by-step explanation:
In the past few centuries, the indigenous populations around the world, including the Americas, have suffered great losses. This has been due to the colonization, forced marriages, forced assimilation, or even genocides. Some indignous people have been luckier than others, and they have managed to survive as such until modern times.
The majority of these tribes in the Americas are located in the Amazon. The reason is simple, it is a huge area that is offering everything they need for survival, but stops the modern civilization from reaching and influence them. It is estimated that around 350 indigenous groups live in this area, though there is every chance that there are more, considering that it is small populations in question which are extremely hard to be found or contacted.