From wikipedia
"There are 6,000 Torres Strait Islanders who live in the area of the Torres Strait, and 42,000 others who live outside of this area, mostly in the north of Queensland, particularly in Townsville and Cairns. [1]
Culture
The indigenous people of the Torres Strait have a distinct culture which has slight variants on the different islands where they live. They are a sea-faring people, and engaged in trade with people of Papua New Guinea. The culture is complex, with some Australian elements, some Papuan elements, and Austronesian elements, just like the languages. The Islanders seem to have been the dominant culture for many centuries, and neighbouring Aboriginal and Papuan cultures show some Island influence in religious ceremonies and the like.
Archaeological, linguistic and folk history evidence suggests that the core of Island culture is Austronesian. Unlike the indigenous peoples of mainland Australia, the islanders were traditionally agriculturalists although they supplemented their food supplies through hunting and gathering.[citation needed]
Their more recent, post-colonization history has seen new cultural influences, most notably the place of Christianity (particularly of the Baptist and Anglican strains) which caused major shifts in cultural paradigms, as well as subtler additions through the influence of Polynesian (particularly Rotuman) pearl-divers brought by black-birders in the 19th Century."
http://en.wikipedia.org/wiki/Torres_Strait_IslandersFrom Wikipedia,
The history of the Aeta continues to confound anthropologists and archaeologists. One theory suggests that the Aeta are the descendants of the original inhabitants of the Philippines, who, contrary to their sea-faring Austronesian neighbors, arrived through land bridges that linked the country with the Asian mainland about 30,000 years ago. Unlike many of their Austronesian counterparts, the Aetas have shown resistance to change. The attempts of the Spaniards to settle them in reducciones or reservations all throughout Spanish rule failed.
While resisting change from the other society for hundreds of years, the Aetas have adjusted to social, economic, cultural, and political pressures with remarkable resilience; they have created systems and structures within their culture to cushion the sudden impact of change.
http://en.wikipedia.org/wiki/AetaHaving been around the world a few times these are the only 2 cultures I have found at all fitting your requirements Ranger. The Torres Strait islanders are doing very well, they are by far the most successfully adapted aboriginal culture in Australia. The Aeta of the Philippines are very interesting, they struggle but they are still a real culture in the area of my home there. These 2 examples are polar opposites in that the TI people are within one of the richest countries in the world and won land rights before any mainlanders did. The Aeta are dirt poor and have no land at all, but they still farm the river beds in the dry season and hunt deer in the mountains. They also collect wild honey.
The second challenge. Can't see it. I can't see any western paradigm shift in time to adapt to what's on the event horizon, But then I don't think of the USA as a culture. Modern English is a made up language, not really a culture, so is the legal system. Can the mongrels outlast the purebreds? Can the hybrid reinvent itself into something never seen before? There is a relative newness about the kinds of humans these days which is not easily defined and has never been really tested in it's ability to survive hardship.