Contact has brought misery, disease, conflict and exploitation to other Indian groups in Brazil. It is a humanitarian imperative that they are left alone, and that their right to be left alone is not only respected but enforced in law.
On the southern fringes of the Amazon, in an area of dense rainforest in Mato Grosso do Sul state, a small band of people are on the run.
You probably haven't heard of them, and they haven't heard of you, but as one of the last uncontacted tribes on Earth that is unlikely to bother them all that much.
They are known as the Kawahiva, and the increasing encroachment of loggers and other outsiders into their lands threatens to wipe out their society forever.
The smallest amount of contact with outsiders could be deadly for them. A handshake, a hug, a brush with a piece of clothing, any physical proximity could transmit infectious diseases that could decimate the entire tribe.
Without rainforest, they will run out of food, dependent as they are on hunting small game and gathering fruits, nuts and berries in the Amazonian jungle. Their lifestyle is completely sustainable, but without the active intervention of outsiders to protect their rights and their lands it will not be sustained.
The situation is unambiguous and clear; the Kawahiva face genocide and it is time for the world to act.
An avoidable genocide
There is a common misconception that tribal peoples around the world are all doomed. Considering the direction that, say, American or Australian history has taken over the past few centuries, this is unsurprising. Unfortunately it has led to a certain amount of fatalism in the here and now.
Around the world, millions live in tribal societies quite happily, and very viably, with no particular desire to be integrated with what we mistakenly describe as 'modernity'.
Our industrialised, hyper-accelerated world holds little attraction for tribes like the Kawahiva, but we should not mistake this for a primitive or conservative nature on their part. Hunter-gatherer lifestyles are neither fixed nor restrictive, and are just as viable now as they ever were.
Any attempt to claim that tribespeople are fated to either become 'modern' or die out is really an attempt to forcibly impose our way of life upon them.
Many tribal people have absolutely no contact with the outside world. This does not mean that they never have, indeed it is highly probable that many are the descendants of people who quite sensibly fled the ravages of colonial brutality.
They are not 'pristine' societies either, whatever that means. They have contact with other tribal neighbours, and through them they may have knowledge of the wider world. Their ways of life are not fixed or inflexible either simply because they are different to ours. They change as and when it is desirable or necessary, and are perfectly capable of determining their own futures.
And the Kawahiva are no exception: they have already had to radically reorganize their society and adapt to their changing environment as a result of violence and the destruction of their forest home.
Old clearings in the forest suggest that several generations ago they probably cultivated corn and manioc and lived a more settled life. But in the last 30 years, they have been forced to flee waves of attacks and invasions and probably became nomads in order to survive. The last garden in their territory was found when a new highway cut through the region over three decades ago.
Now, the Kawahiva have been forced to adopt a nomadic lifestyle. They set up temporary camps where they stay for several days, before moving on to evade intruders.
The importance of leaving them be
They are nonetheless highly vulnerable to contact with outsiders. They have no immunity to Afro-Eurasian diseases like flu and the common cold which can kill them, and can easily be targeted by unscrupulous individuals willing to use violence to clear them out of the way.
It is imperative that they are left alone if they choose to remain uncontacted, as they cannot in any sense offer consent to what could be a fatal first contact with the world beyond their borders.
Most of the one hundred or so uncontacted tribes we know of are concentrated in the Amazon and we can formulate guesses as to what their culture and language might be like. In many cases, there is a perceptible desire to remain uncontacted, demonstrated in cautious hostility to outsiders, or a tendency to flee when unfamiliar figures start marching towards them through the jungle.
We also know that in recent history, as in the colonial past, contact has proven catastrophic for the indigenous peoples of the Americas. It has brought misery, disease, conflict and exploitation to other Indian groups in Brazil. It is a humanitarian imperative that these people are left alone, and that their right to be left alone is not only respected but enforced in law.
The threats facing tribes like the Kawahiva are not complex. They have almost become cliches of all news that comes out of the Amazon, rhetorical shorthands which are too easily brushed aside. Slash and burn farmers destroy the forests to grow maize, sugar and soya, ranchers create fenced-off grasslands for the meat industry, loggers go to great lengths to rip valuable hardwoods from the forest.
Hope on the horizon
Despite the persistence of these problems we should not be deterred from doing all that we can to prevent them from continuing.
The natural riches of the Amazon, and fellow human beings like the Kawahiva who have successfully conserved them for generations and depend on them for their very existence, cannot be thrown away for the sake of short term economic considerations. 'Development' in the Kawahiva's indigenous territory would be nothing short of genocide.
The situation facing the Kawahiva is far from hopeless. If their right to remain on their land undisturbed is respected, they will be able not only to survive, but to flourish. Since 2013, a decree to make the Kawahiva's land a designated Indigenous Territory has been sitting on the desk of the Brazilian Minister of Justice. All it requires is his signature (see portrait of justice minister .
Survival International, the global movement for tribal peoples' rights, is urging him to act to save the Kawahiva from extinction. For the sake not just of the Kawahiva people themselves but for all humanity, it is essential that he acts to prevent an appalling tragedy.
Action: Send an email to Brazil's Minister of Justice demanding that he save the Last of the Kawahiva by protecting their land.
Lewis Evans is an author, and a campaigner at Survival International.
Learn more about the Kawahiva and to see what you can do to help protect them, visit Survival International's Kwahiva campaign page.