New Genetic Study Suggests Modern Flores Island Pygmies and Ancient Hobbits Are Unrelated | Science

Liang Bua Cave on Flores Island, where remains of Homo floresiensis were discovered in 2003. Nearby is a village where pygmies live.
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Geneticist Serena Tucci sat in the small Indonesian village of Rampasasa on the island of Flores, the only woman in a room full of male researchers and pygmy villagers. Smoke from clove cigarettes swirled through the air and the villagers, whose average height was about 4.5 feet, offered their guests palm wine made from the sap of nearby trees. Slowly, with the help of translators working in three different languages, Tucci and his colleagues explained why they wanted to collect blood and saliva from the villagers.

Clear communication was important, Tucci now says of that 2013 research trip. Scientists have made a lot of mistakes in the past when working with the DNA of indigenous peoples. But once the villagers understood, they were excited. They wanted to know what their genetics could reveal about their personal history. They wanted to know if they were descendants of the ancient hominins that once inhabited their island, Homo floresiensissometimes called hobbits for their resemblance to Tolkien’s fictional creatures.

“The discovery of Floresiensis was one of the most important discoveries of the century and the fact that [the modern pygmies] live in a village very close to the cave [where Floresiensis remains were found] makes them even more interesting,” says Tucci.

The results of their research are published today in the journal Science: modern pygmies have nothing to do with Homo floresiensis-although they contain genetic material from Neanderthals and Denisovans, two extinct hominin lines. While many modern humans have traces of extinct hominins in their DNA, the particular admixture seen in pygmies is unique and tells a fascinating story of how people from different regions – the islands of Southeast Asia and the East Asian coast – have mixed on this island. .

“We were unable to obtain DNA from Homo floresiensis. At least three ancient DNA labs have tried,” Debbie Argue, a paleoanthropologist at the research-unaffiliated Australian National University, said by email. “This study used a DNA statistical method to see if the DNA of Rampasasa individuals had any indication of unidentified hominin lines. It doesn’t, so that puts the nail in the coffin for all those who still thought that the Homo floresiensis the remains were somehow related to modern humans.

For many paleoanthropologists, this final highlight has been a long time coming. The discovery of the tiny remains in Liang Bua Cave, announced in 2004, set the world of paleoanthropology on fire. The skeletons were originally dated to 18,000 years ago, meaning the tiny Flores people could have existed in Indonesia at the same time as the modern Homo sapiens. The adult remains were tiny, less than four feet tall, and had many other strange features. Their skulls had a brow ridge, like that of other ancient hominids, but instead of being a continuous bump on their forehead, it separated into two sections. Their feet were huge, much more like the feet of apes than those of humans. The mix of modern and archaic traits was a puzzle that scientists struggled to solve.

“This is the most extreme hominid ever discovered,” paleoanthropologists Marta Mirazon Lahr and Robert Foley wrote in 2004. “An archaic hominin to this date changes our understanding of the geography, biology, and culture of the late human evolution.”

Several factors made hobbits particularly fascinating. First, their proximity to another ancient hominin species –homo erectus. The first fossil remains of ‘standing man’ were discovered on the neighboring Indonesian island of Java in 1891. The tiny Homo floresiensis to be a descendant of homo erectus? Could his environment have been the reason he got so small?

Flores, although in the same archipelago as Java, is separated by an important geological boundary known as the Wallace’s Line. “Getting from Java to Flores requires multiple crossings of deep channels and treacherous currents, including one of at least 25 kilometers,” writes John Langdon in The Science of Human Evolution: Doing It Right. This means that Flores was home to a very limited number of mammals – hominids, rats and relatives of elephants known as Stegodon— so food resources could have been scarce. Maybe the hobbits were small because it was the only way to survive.

But other scientists vehemently disagreed that hobbits deserved their own taxonomic category. They argued that the remains belonged to Homo sapiens stricken with an unknown condition: possibly microcephaly (having an abnormally small brain) or a hormonal condition that has caused stunted growth. The pathological hypothesis, although it never achieved full scientific consensus, remained a thorn in the side of researchers who wanted to treat Homo floresiensis as a new species.

All that seemed to change in 2016, when a new series of encounters placed the Homo floresiensis remains at 60,000 to 100,000 years ago, rather than just 18,000. A separate group of researchers found more remains on another part of the island, similar to the Homo floresiensis skeleton in Liang Bua Cave, only these remains are dated to 700,000 years ago. With thousands of stone tools dating back nearly a million years ago, the growing body of evidence seemed to be shifting solidly in favor of an ancient and strange species of hominin that made Flores Island its home for tens of thousands of years.

If these second sets of dates are correct, it is not surprising that modern pygmies have no connection with Homo floresiensis, says study author Ed Green, a biomolecular engineer at the University of California, Santa Cruz. What surprised him was what they found about the genetics of short people: their genes that code for height (or lack thereof) are in all of us.

“There’s a whole bunch of variation in all human populations, so if you have to be brief, there’s the genetic material [available]. You just select on it and you can be small,” says Green. Basically, pygmy villagers aren’t special in terms of genetics; anyone could be significantly shorter if the right genes were selected.

As to what the Rampasasa Pygmies themselves think of the results of the study, that remains to be seen. In a village without a phone or internet, data sharing is a bit of a logistical hurdle. “We are now working to set up a new expedition to Flores to report the results,” says Tucci. She worked with an illustrator to visually convey the results of the study, so that the villagers would remember their collaboration with the scientists. They will also learn about their own migratory history, how genetic data shows their ancestors mixed with populations from East Asia and Melanesia. Even though their story doesn’t include the mysterious hobbits, it’s still part of the amazing journey Homo sapiens made across land and sea to the four corners of the world.

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