Amerindians of Brazil more numerous than you think

A few months ago I was thinking a fair amount about the Neandertals. One issue which became more stark to me due to that particular finding, that a few percent of the human genome seems to have derived from Neandertal populations, is the reality that genetic distinctiveness can persist long after cultural coherency is no longer a reality. That made me reconsider one of the facts of contemporary scholarship, that the Amerindian populations of the two most populous nations of the New World, the United States of America and Brazil, have disappeared or been totally marginalized demographically. I've observed before it looks like that about 15-20% of the ancestry of the Argentine population is Amerindian, despite the nation's proud identity as a European settler offshoot (i.e., more like the United States or Australia, than Mexico, which has an explicit hybrid identity). But I realized that Brazil was perhaps the bigger ...