I think The Revenant and Apocalypto work exceptionally well as companion-pieces, because (although this theme is obviously more heavily stated by Mel Gibson) as well as being survival horror epics, they are also very much in the post-apocalyptic genre. Both film-makers have understood very well that North America after 1492 is best conceptualised in that vein - as a continent which has experienced something akin to a nuclear war or alien invasion. Civilization has been shattered, somewhere between two-thirds and nine-tenths of the population have died, and the survivors are fighting over the fragments of what is left and trying to cling on to whatever vestiges of their humanity remain. In RPG terms, this is Gamma World, not D&D.
I'm more alive to this comparison because I've recently been re-reading Charles C. Mann's 1491, although my copy has the blander name "Ancient Americans" (perhaps this is the British title). More than any other author I've read - although I'm by no means an expert - Mann manages to bring across a sense of the scale of what took place in the Americas in the early colonial period. There is a big dispute about the numbers, for instance, but it seems fairly likely from the evidence available that before Pizarro had even arrived in the Inca empire, and before most South Americans had ever seen a white person, up to half of the population of the empire may already have died of smallpox, brought to the Caribbean by the Spanish and spread from Central America. It was thus an event of similar size and consequence to the Black Death in Europe - an episode which had brought an entire continent to its knees in an orgy of communal blood-letting. No wonder the Incas were uniquely vulnerable to Spanish invaders - Pizarro arrived almost exactly the moment a decisive battle was taking place between competing factions for the throne of the Inca empire: a society where one out of every two people had recently died.
This pattern, of course, was repeated all over the continent. European diseases killed the vast majority of the population - whether 60% or 90%, either way it was a disaster the like of which has never been seen before or since. As Mann puts it, very poignantly:
Living in the era of antibiotics, we find it difficult to imagine the simultaneous deaths of siblings, parents, relatives and friends. As if by a flash of grim light, Indian villages became societies of widows, widowers, and orphans: parents lost their children, and children were suddenly alone. Rare is the human spirit that remains buoyant in a holocaust. "My people have been so unhappy for so long they wish to disincrease, rather than to multiply," a Paiute woman wrote in 1883. A Lakota winter count memorialized the year 1784 with a stark image: a pox-scarred man, alone in a tipi, shooting himself.
According to the second half of Mann's book, the kind of wilderness we see in The Revenant is a product of this catastrophe. The Americas, North and South, were relatively densely populated in 1491, and what we now think of as "wild" areas were actually largely quite carefully managed through the use of slash and burn agricultural techniques. Undergrowth in forests was kept deliberately clear and gaps between trees maintained. This is even true of Amazonia. Early explorers discovered a thickly-populated land with large settlements - even cities. Gaspar de Carvajal discovered a region deep in the Amazon basin which was so densely populated he passed twenty villages in the course of one day, and in one place saw a settlement that "stretched for five leagues without there intervening any space from house to house". The Amazon jungle we know now is a place which has been denuded of its human population, as are the great forests and plains of North America (like, it turns out, much of Siberia and the Highlands of Scotland: artificial wildernesses created by disease and ethnic cleansing rather than naturally-occurring ones).
The Revenant, deliberately or otherwise, brings this sense across very well. The Montana of 1823 was wild and inhospitable but this is because a hundred years or so ago almost everybody died, and the tiny pieces of society left over have been reduced to hostile, antagonistic bands of depressed and weary people. The scenes amongst the Arikara bring that across very movingly: Wikipedia has a source suggesting that their population had been reduced to 20% of its former size by smallpox around 1800 or so - watching their behaviour in the film, you can believe it.