Humans started to spread throughout the
Sahul
megacontinent, which united what is now Australia, Tasmania, New Guinea, and
the Aru Islands, between 75,000 and 50,000 years ago.
More information regarding the pathways taken by these early people and how
long it took them to thoroughly explore Sahul's extremes is now available
thanks to new study. It may have taken these brave individuals up to 10,000
years to cross the wide territory, which is twice as long as
previously believed.
Researchers improved their predictions by creating a new, more complex
model that took into account factors that affect travel, such as the land's
capacity to produce food, the distribution of water sources, and the
geography of the surrounding area.
According to
ecologist Corey Bradshaw
of Flinders University in Australia, "the ways that individuals interact
with terrain, environment, and maybe other people affect our model findings,
yielding more realistic results."
We can now accurately forecast the patterns and procedures that led to the
early settlement of these regions by humans tens of thousands of years
ago.
The researchers integrated the information from two
previously published
studies, one that used a grid-based method to estimate patterns of
population expansion and migration, and the other that plotted the likely
"superhighways" of exploration based on topographic factors.
The revised model not only increased the projection for the amount of time
needed to colonize the megacontinent owing to topographic constraints, but
it also revealed a previously unrecognized new channel of migration through
Sahul's core.
The researchers
explain
in their recently released work that "individuals pass on the knowledge of
the terrain over time to the rest of the population" and that "a person
going on the landscape and picking that basic path repeatedly would likely
lead to migratory corridors."
Most likely, migration started through Timor, then continued through
western New Guinea. Then, rapid development would have taken place north to
New Guinea and south to the Great Australian Bight.
The new model incorporates the impact of the geography on population
expansion, as evidenced by the researchers' suggestion that access to
Tasmania would have been limited by changes in sea level in the Bass
Strait.
According to Bradshaw's
revised modeling, New Guinea was progressively occupied over a period of
5,000 to 6,000 years, with an initial concentration on the Central Highlands
and Arafura Sea region before spreading to the Bismarck Archipelago in the
east.
It is estimated that between 9,000 and 10,000 years after the first arrival
in Sahul, the far southeast and Tasmania were first populated.
In order to describe how Homo sapiens migrated from Africa through Asia and
into the Americas, the researchers believe their findings may be applicable
to other parts of the globe. However, the models would need to be modified
to account for diverse geographical conditions.
The results of archaeological digs might then be used to support and
confirm these hypotheses, as was done in this particular study.
These specifics can be important in terms of where people grow and how
rapidly they spread, whether it be choosing a path that passes through two
mountains rather than over them or staying close to water supplies.
According to
Utah State University archaeologist Stefani Crabtree, "This also goes to highlight the usefulness of merging computational
models with archaeology and anthropology for enhancing our knowledge of
mankind."
The research has been published in
Quaternary Science Reviews.
