The Indonesian island for Flores became famous in 2003 when paleoanthropologists exploring the Liang Bua Cave in western Flores found the tiny skeletons of mysterious humans whose height never exceeded one meter (3.3 feet). Given the unfortunate yet popularity-enhancing nickname of Hobbits, the skeletons were eventually determined to be those of a previously unknown hominin species which is now known as Homo floresiensis. While this discovery opened its own can of mysteries, it was thought to have solved at least one … why the current residents of the nearby village of Rampasasa are also much smaller than average humans. While the Rampasasans liked the idea that they could be descendants of Hobbits, a new study suggests that they’re not … and that the mysterious island of Flores was instead home to two distinct diminutive human species that evolved separately.
“It’s rare in science that you set about to answer a question and you get something of a definitive answer and it’s the end.”
In the journal Science and in an interview with The New York Times, University of California, Santa Cruz, Richard E. Green describes the path taken to identify that the small Rampasasans often referred to using the antiquated name “pygmies” are actually a second short species unrelated to the Homo floresiensis. It was only recently determined that Homo floresiensis was around until just 60,000 years ago and most likely lived with, and possibly had sex with, the new wave of humans. This should be easy to prove – just check the DNA of the Rampasasans for H. floresiensis DNA.
Except … there are no samples of H. floresiensis DNA. The researchers instead looked for segments of a chromosome that have a large number of changes that don’t show up in the rest of the population, which indicates interspecies co-mingling. Sure enough, they found indications of Neanderthals and Denisovans ancestries, which could have come from mating with homo sapiens with those ancestors. What they didn’t find is anything remotely indicating the Rampasasans were descendants of the Hobbits. That means they evolved their shortness on their own.
How did two distinct groups end up diminutive? One predominant theory is that Homo floresiensis people were already small when they migrated to Flores, and living on an isolated piece of land lead to what is now called “island dwarfism” – a condition where isolation, a small living space, nutrition, lack of larger enemies and other factors allow for smaller members to rise to the top. This is also the case for animals, as Flores was once home to a dwarf elephant. The current Rampasasans, while larger than the Hobbits, are still well below world averages in size and it’s becoming clear that “island dwarfism” struck twice – they are still isolated on a tiny island and still have poor nutrition and living conditions. Over generations, this also becomes a genetic variant that is passed down – a double whammy that prevents Flores from ever having a competitive basketball team. Unfortunately, they’re also diminishing in numbers like the Hobbits eventually did when the island was invaded by the larger homo sapiens.
So the Rampasasans can’t blame the Hobbits for their size … both have to blame the island they ended up on. This sounds like a variation on “Lost” without a dream ending.