Homo floresiensis, popularly known as hobbits, marked one of this century's most astonishing discoveries. The island on which the hobbits lived is home to a more recent group of small humans. However, genetic studies of modern Flores inhabitants have shown they didn't inherit their short stature from their predecessors. Flores, also home to a series of pygmy elephant species, is apparently particularly prone to the phenomenon of island dwarfism.
The human evolutionary tree looks increasingly like a jumbled maze, rather than a linear path leading to us. Most other human species died out long ago, which is one of the reasons H. floresiensis was such a surprise. Hobbits were living on Flores until at most 60,000 years ago and possibly co-inhabiting the island with Homo sapiens, who had reached nearby Australia before then.
Today, the village of Rampasasa is made up of people whose average adult height is 145 centimeters (4.8 feet), taller than the 107-centimeter-high (3.5-foot-high) hobbits, but still one of the world's smallest populations. Rampasasa's proximity to the Liang Bua cave, where H. floresiensis remains were first discovered, raised a question: Might hobbits and Homo sapiens have interbred, with the genes for shortness surviving among the Rampasasans? After all, we already know that interbreeding with Neanderthals, Denisovans, and another mysterious population has altered our genes.
However, a paper in Science puts to rest the romantic idea that hobbits live on in the genes of some modern people. Establishing this wasn’t easy since we have not been able to extract any DNA from hobbit fossils.
Instead, a team led by Dr Richard Green of the University of California, Santa Cruz, compared the DNA of 32 people from Rampasasa with samples taken across the world. They found a fairly typical genome for modern humans. There were no substantial sections of DNA unseen in the rest of the world, as would be expected if the Rampasasans’ ancestors had once got friendly with hobbits.
Instead, the team found more Neanderthal and Denisovan legacy than on other South-East Asia islands, but less than in Oceania, consistent with the Rampasasan's heritage being about three-quarters from Asia and a quarter from New Guinea.
"If there was any chance to know the hobbit genetically from the genomes of extant humans, this would have been it,” Green said in a statement. "But we don't see it. There is no indication of gene flow from the hobbit into people living today."
"It sounds like a boring result, but it's actually quite meaningful," Green added. While the genes that made the Rampasasans short exist across humanity, they were brought to the fore by the local conditions, which favored shortness.