Before the vine-swinging gets underway in the latest film version of Edgar Rice Burrough’s story about a white child brought up by apes, we might remember that for years before the 1912 debut of Tarzan of the Apes in the All-Story Magazine, Americans and Europeans had been hearing stories of white men going native in Africa, not just in adventure fiction, but in explorers’ reports, newspaper accounts, and scientific journals. It wasn’t just orphaned aristocrats that were going missing, but entire white communities. While exploring East Africa in 1876, five years after his famous meeting with David Livingstone, Henry Morton Stanley encountered some Africans whose light complexion and European features aroused his curiosity “to the highest pitch.” They came from the slopes of Gambaragara, a snow-capped mountain west of Lake Victoria. That such a towering range existed in the heart of equatorial Africa was astonishing enough. “But what gives it peculiar interest,” Stanley wrote, “is that on its cold and lonely top dwell a people of an entirely distinct race, being white, like Europeans.” Stanley’s claim caused a sensation. In the months ahead, it was reported all over the world.
Other explorers brought home similar stories. In 1904, University of Chicago anthropologist Frederick Starr brought back nine hundred feet of motion picture film to document the Ainu of Hokkaido as the “aboriginal Caucasian inhabitants of Japan.” The same year that Tarzan came to press in 1912, Canadian anthropologist Vilhjalmur Stefansson returned from the Arctic reporting the discovery of “Blond Eskimos” who behaved like the Inuit but looked “like sunburned, but naturally fair Scandinavians.” A few years later, the American entrepreneur Richard Marsh returned to Washington from an expedition to Panama where he reported the discovery of “White Indians.”
Vilhjalmur Stefansson
Scientists sifted through the reports of these anomalous encounters— flaxen-haired Indians, blue-eyed Inuit, round-eyed Japanese— in hopes of connecting the dots of racial geography to form a picture of the white racial past. Out of these efforts came a theory, the Hamitic Hypothesis –named after Ham, the cursed son of Noah from Genesis 9– positing that the world’s light-complexioned indigenes were the result of an ancient Caucasian invasion from Central Asia. As it turns out, none of these white tribes turned out to be white, at least in the racial sense of the term intended by explorers. The “White Indians” of Panama were albinos, the Ainu of Japan and the “Blond Eskimos” of Victoria Island descended from ethnic groups distinct from the general population. Henry Morton Stanley’s “white race of Gambaragara” remains a mystery, but may have been a population of light-skinned East Africans who lived in the rainforests of the Ruwenzori Mountains.
Yet the legacy of these discoveries had profound consequences for the world, especially for the people of Africa. In the existence of white tribes, Europeans found justification for their conquest and colonization of the world. If the European race had its own long history on the continent, it followed that the Europeans who followed Stanley into Africa were not settling, but re-settling, lands that had been conquered by fair-skinned invaders centuries before. As such, the white-complexioned Gambaragarans provided supporting evidence to an argument that redefined Africa’s past, and more importantly set its course for the century ahead.
None of this should be laid at the door of Edgar Rice Burroughs. He was a pencil sharpener wholesaler when he wrote Tarzan of the Apes. His novel reflected, rather than directed, the events of his age. Yet beneath its fantastic plot lay a thought experiment. How would an Englishman without his tweeds, gun, and Oxford degree size up alongside the African? How would a viscount or earl perform once the veneer of polite society had been stripped away? The answer: pretty awesome. This is the racial fantasy that, despite its many revisions and movie incarnations, clings Jane-like to Tarzan as he swings through the twenty-first century.
For more on this subject, read (shameless plug) my book: 
The Lost White Tribe: Explorers, Scientists, and the Theory that Changed a Continent
Time to Eat the Dogs 
Great synopsis.