40,000 years of adapting to sea-level change: the story of Alor’s first peoples.


Early people were island hopping and rapidly adapting to climate change as they made their way towards Australia tens of thousands of years ago.

Archaeological discoveries — including shells, fish bones and fishhooks — paint a picture of how people lived and adapted to the environment over 40,000 years ago.

The new evidence of how and when people occupied a coastal cave on Alor has pushed back the date of known human occupation on the small Indonesian island by more 20,000 years. 

CABAH researchers worked alongside Indonesian colleagues and local people to locate and then excavate a large cave called Makpan on Alor’s south-west coast on mid-2016.

The cave has preserved evidence of people who lived there tens of thousands of years ago, including tools made from stone, shell, and coral, as well as the remains of marine shell and sea urchins, for which people are the only likely transport agents from coast to cave.

Wallace's Line and the islands of Alor and Timor-Leste.
What we know
The small island of Alor was a passage between the larger islands of Flores and Timor.
How we know it
Researchers used radiocarbon dating and preserved charcoal and marine shells to establish the times when people were occupying the cave.

The findings, published today in Quaternary Science Reviews shows that Alor was occupied around the same time as Flores to the west, and Timor to the east – confirming Alor’s position as a ‘stepping-stone’ between these two larger islands.

Dr Shimona Kealy, from the Australian National University, said analysis of the range of artifacts found at Makpan also demonstrate how inventive and adaptive early people living there were. 

“This new record provides further insights into early modern human movements and patterns of occupation between the islands and shows how responsive people were to challenges, such as climate change,” she says.

“Occupation of this age demonstrates that once people began to move into the islands they did so very quickly, and rapidly adjusted to their new island homes.”

The team, led by Professor Sue O’Connor, used radiocarbon dating of preserved charcoal and marine shells to establish the times when people were occupying the cave.

The excavation site inside Makpan cave on Alor Island where shells, fish bones and fishhooks were found.
A bumphead parrotfish with a school of Fusiliers near Alor Island. Credit: Agefotostock/Alamy Stock.
Palaeogeographic reconstructions of western Alor and the Pantar Strait.

Over its 43,000 years of human occupation Makpan witnessed a series of massive sea level highs and lows that resulted from the climactic extremes of the last Ice Age. 

“When people first arrived at Makpan, they came in low numbers,” Dr Kealy explains. “At this time the cave was close to the coast — as it is today — and this early community lived on a diet of shellfish, barnacles and sea urchin, with sea urchins in particular, eaten in large numbers.”

Shortly after their initial arrival, sea level began to fall so that Alor became joined to Pantar island to the west, creating a mega-island almost double in size.

This had the result of closing the channel which today exists between Pantar and Alor (the Pantar strait) through which strong ocean currents connect the Flores and Savu seas. Instead the strait was replaced by a large sheltered bay.

Falling sea levels as the last Ice Age reached its maximum extent, also increased the distance from the site of Makpan to the coast. This increased distance likely encouraged people to broaden their diet away from an intensely marine focus, to include a variety of land-based fruits and vegetables and perhaps make more use of the giant rats which were the only terrestrial fauna of any size available on the island at this time.

This scenario is supported by analysis of human teeth from Makpan.

As the last Ice Age began to wane, about 14,000 years ago, Makpan was once more within 1km of the coast. And the finds from this period show an increased use of marine resources and foraging in the sheltered bay region, rocky coastline, reefs, and deeper waters off Alor’s south coast.

Around 12,000 years ago, people were enjoying a “smorgasbord of seafoods”, says Professor O’Connor.

“It is no surprise that the site sees significant evidence for fishing at this time, not just the bones of a wide variety of fish and shark species, but also in the form of shell fishhooks in different shapes and sizes,” she says.

The team also found fishing tools, such as sinkers, as well as files made of coral used to make hooks. These hooks were made from marine shell species with an inner shiny layer known as ‘nacre’, — which may have helped to attract fish.

Marine shell and coral fishing (at left) and ornamentation (at right) technologies from Makpan. (A) rotating fishhook (B) jabbing fishhook (C) small jabbing fishhook (D) possible shell lure (E) large jabbing fishhook (F) perforated coral sinker (G) finger-coral tool (H) selection of single-holed disc beads and two-holed oval beads made on Nautilus pompilius.

“The diversity of fishhook types found in Makpan implies the use of fibre lines and nets, and the ability to fish in both shallow and deep water,” says Professor Sue O’Connor. “Shell was also used to make a range of items for personal decoration such as beads to wear and to sew onto fabric.”

As sea levels continued to rise, the Pantar Strait opened up once more and we see the loss of the sheltered bay resources from the Makpan diet alongside an increase in reliance on terrestrial foods. This coincided with a decline in occupation intensity, culminating in the abandonment of Makpan about 7,000 years ago. 

“We don’t know why Makpan was abandoned at this time,” says Dr Kealy. “Perhaps these final sea level increases made other areas around Alor island more attractive settlement locations, encouraging people to re-locate.”

The cave was occupied again around 3,500 years ago, but Dr Kealy says: “Evidence for occupation was less dense during this final phase, as communities were likely living in settled open villages and would only have visited Makpan cave during occasional fishing and shellfish collecting forays.”

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