Our Global Neighbours: New dating H. floresiensis

Pleistocene people of Flores: Hobbit's part of the story.

Our Global Neighbours is a blog series containing stories from and about cultures around the world.

The story of human origin is complex and a single discovery; revised dating or “narrow” genetic studies may contribute but not resolved existing hypotheses.

It is good news that the original dating of Homo floresiensis has just been revised. The new dating (published in Nature) indicates that skeletal remains from the cave Liang Bua on the Indonesian island of Flores is between about 100,000 and 60,000 years old, rather than 12,000 years old as previous dating suggested.

12,000 years always looked odd and researchers grappled with this unusual evidence. Mostly they could not reconcile that H. floresiensis which shows physical characteristics more primitive than the oldest H. erectus remains anywhere in Asia, continued to live on Flores well into a period completely dominated, as we thought, by entirely modern human lineage.

The new, older date for H. floresiensis seemingly resolves this acute dilemma. For now the story is simpler: around this time (100,000-60,000 years ago) modern Homo sapience arrives in Southeast Asia, causing extinction of H. floresiensis. And it also triggers a demise of local megafauna "very reminiscent of the Australian situation." The correlation of peopling the Australian continent and blanket extinction of megafauna is far from clear and a similar scenario only impressionistic rather than proven for Flores.

It is broadly accepted that H. erectus spread from its African cradle close to two million years ago. Its remains discovered in Java are dated to about 1.6 and in China 1.7 million years ago. We have to accept that these early humans evolved through this long period of time. Does H. floresiensis indicate that such evolution indeed occurred in East and Southeast Asia, even if it is unclear how they fit into a broader picture of human genealogy?

I sense that the current scenario for older H. floresiensis would favour, if not reinforce, out-of-Africa theory for modern humans spreading through our region. And yet, a prominent proponent of this theory, Chris Stringer remarks about H. floresiensis “It would mean that a whole branch of the human evolutionary tree in Asia had been missing until those fateful discoveries in Liang Bua.”