Guajajara last names

Q:  I was looking up an article about an indigenous activist who was killed last year, Paulo Guajajara. On the website I saw two other people, a politician (Sonia Guajajara) and an artist (Jahy Guajajara), who also have the same last name. But when I went to the links, I could not find any information to tell me if they are relatives or it's just a common last name for indigenous people in Brazil to have, can you explain?

A: Last names are not traditional in most indigenous tribes of South America. Many Native people have adopted Spanish or Portuguese last names, and some continue to use single names with no last name at all, but in some communities, indigenous people simply began using their tribal name as a surname. Guajajara is actually a tribe in Brazil, with almost 15,000 members, and most of them have the same last name. This is confusing to outsiders, but represents a strong sense of tribal identity to the people.

As far as I know, Paulo Guajajara was not a literal relative of Sonia Guajajara, but they are members of the same tribe.

Hope that helps!

Further reading:
Guajajara language
Indigenous people of Brazil
Native American names