A set of strange fossils of human ancestors described as a “hobbit” were discovered more than ten years ago on the Indonesian island of Flores.
They showed a bizarrely small species of human, later christened Homo floresiensis. They were later nicknamed the “hobbit” due to their small stature. Researchers previously thought that the species lived as recently as 18,000 years ago. Others estimated that they walked the Earth as recently as 11,000 years ago, writes Eva Botkin-Kowacki for the Christian Science Monitor.
Scientists revise age of “hobbit” fossils
If that were true that would have made the hobbit the last remaining human that isn’t Homo sapiens. However a new study reveals that the fossils are in fact between 100,000 and 60,000 years old.
This may seem like a huge discrepancy, but it turns out that erosion is to blame. Scientists date the fossils by working out how long sediment layers have covered them. However some of the layers had been eroded, making it seem as though they were younger than they are.
Now a team of researchers has published the results of its research in the journal Nature.
Further research reveals more information on human ancestors
“The initial excavations were sampling very small areas,” says study author Matthew W. Tocheri, a researcher at the Smithsonian’s Human Origins Program, in a phone interview with The Christian Science Monitor. “You don’t get to see the full picture.”
Tocheri likens it to putting a puzzle together. “If you only pull out two pieces and try to fit them together, a lot of the time the pictures that you make from that are going to be very different than after you’ve pulled out 15 or 20 pieces of the puzzle,” he said.
Further research at the site where the fossils were discovered has allowed the team to find more pieces of the puzzle. They found that sediment in the cave had not been deposited continuously and a layer was missing.
They then used a combination of dating techniques to determine that the fossils were between 100,000 and 60,000 years old. A number of stone artifacts related to the fossils were dated between 190,000 to 50,000 years old.
“In many ways, science does correct itself. By continually investigating a site, you sometimes find minor errors that you made in the earlier interpretations and then you want to revise those interpretations,” explains Russell L. Ciochon, a paleoanthropologist at the University of Iowa in Iowa City, who was not part of the study, in an interview with the Monitor.
How to explain H. floresiensis?
Scientists believe that the hobbit got so small due to a case of island dwarfism. The population arrived normal size but grew smaller due to evolutionary selection. Island dwarfism has been seen in other animals like elephants, but “this is the only example we have of island dwarfing of a human lineage,” says Dr. Ciochon.
However another theory is that the hobbits could be descended from another premodern Homo species that was smaller-bodied and smaller-brained. There is still a possibility that younger H. floresiensis fossils are discovered elsewhere.
Regardless, H. floresiensis “highlights how much variation there probably was in the human family tree,” Daniel Lieberman, a paleoanthropologist at Harvard University who was not part of the study.
“Our genetic diversity as a family group was far more greater in the past than it is today. And that’s from a genetic perspective, that’s from a morphological perspective, it’s from a behavioral perspective,” Tocheri says. “It’s easy for us to forget because we’re the only ones left that can pontificate about what it means to be human.
