american natives require genetic testing as proof of ancestry for aboriginal title 

given the financial incentives there is indeed a great potential for mischief
but self policing could be the answer

How dos some determine which people are  legitimate biological relatives?
They started to focus on what’s known as “blood quantum” as a way of counting ancestors who were enrolled as Native American. In most US tribes, you have a specific blood quantum needed for enrolment – often one-quarter. That means you have to be able to show with paper documentation that you have one out of four grandparents who is full blood. 

There are also traditional people who don’t want to have a molecular narrative of history shoved down their throats. They would prefer to privilege the tribal creation stories that root us in the landscapes we come from.