Technology didn’t future-proof shrinking hobbit

Posted by | October 25, 2016 | Our past, present and future | No Comments

For more than a decade, UNE archaeologist Dr Mark Moore has been extending our understanding of human evolution — one ancient stone tool at a time.

A population of Homo erectus, stranded on the island of Flores, shrank over 300,000 years, evolving into a new species.

Mark Moore examines stone artefacts in a knapping pit

Dr Mark Moore, Senior Lecturer, Stone Tools and Cognition Hub, School of Humanities, UNE

Dr Mark Moore was part of the extraordinary discovery of Homo floresiensis in 2003 led by Professor Mike Morwood from UNE. Known as ‘the Hobbit’ for its small size, this previously unknown species was found on the Indonesian island of Flores. The remarkable outcome of this discovery was the fundamental impact it had on scientific understandings of human evolution. Now Dr Moore has been part of another major find which casts light on how the Hobbit evolved.

A population of Homo erectus, stranded on the island, shrank over 300,000 years, evolving into the new species. Dr Moore, archaeologist and stone tool specialist, said a mandible fragment and six isolated teeth, belonging to at least three individuals, were discovered in 2016 in deposits dating back 700,000 years. The fossils were found next to stone tools in layers of sandstone at the site of Mata Menge, located in the Soía Basin of central Flores.

Analysis of these new fossils from Mata Menge supports the hypothesis that Homo floresiensis evolved from a population of large-bodied Homo erectus that were stranded on the island and subjected to ‘Island Rule’.

This is where selective pressures unique to islands cause large-bodied animal species to become smaller over time,’ said Dr Moore.

As part of the study, Dr Moore taught himself ancient stoneworking to better understand the tools. “Making stone tools isn’t as easy as it sounds. Controlling the process requires complex mental evaluations of geometrical configurations on the stone, and blows that are simultaneously controlled and forceful. The hominins were small, but powerful. Much of the stone they flaked was coarse-grained volcanic rock, but they had an eye for easier material, and frequently collected small, high quality flint-like pebbles during their stone forays.

“We found stone tools in direct association with the new fossils. The toolkits themselves were simple, comprising knife-like flakes for various cutting tasks, and the stout-edged cobble cores (pictured in banner) they were struck from—which were suitable as heavy chopping tools. The edges of the flakes were sometimes trimmed, perhaps to resharpen them or modify their shape.”

The Flores hominins used advanced stone tools to survive but ultimately the natural adversity overcame their species. Dr Moore found that the Flores hominins continued to make simple stone tools to survive but the tools didn’t buffer them from the extremes of selective pressures encountered on the island.

“Their skeletal anatomy and body shape morphed and their cranial capacity dramatically decreased. A technological adaptation didn’t seem to shelter them from the evolutionary process of island endemism. So maybe technology isn’t always the buffer against natural selection that we intuitively think it is — with implications for us more generally.”

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