PEOPLE have the flexibility to cope with enormous changes in their environment.
They should have little trouble adapting to the greenhouse world, claimed
Rhys Jones, a prehistorian at the Australian National University in Canberra.
‘In the past, people experienced massive climatic changes on a scale that
makes the greenhouse effect look like chicken feed,’ he said.
The prehistoric record of Australia contains lessons for scientists
worrying about global warming. The most important lesson is that despite
huge upheavals, people remained much the same. ‘The South Pacific experienced
massive transformations on a scale we can’t envisage, yet the human record
is relatively unchanged,’ said Jones.
‘Climatic upheavals affected people locally but not on a broader scale,’
he said. Prehistoric sites around Australia, as far apart as Kakadu in the
Northern Territory and Tasmania in the south, show that the climate changed
markedly. But people continued to live in much the same way as they had
for tens of thousands of years.
Human settlement in Australia dates back far beyond the last ice age,
perhaps as far as 60 000 years ago, according to the most recent studies.
The most extreme climate that Aboriginal people encountered was at the height
of the last ice age, when temperatures were between 8 and 10 Degree C lower
than they are now, and the sea level was 150 metres below the present level.
Ferocious, cold, dry winds blew across much of the land, carrying dust
from the central deserts of the continent. Yet people adapted to these harsh
conditions. And although most changes seem to have happened over periods
of hundreds or thousands of years, some changes might have been relatively
sudden, said Jones.
The archaeological sequence at the site at Kakadu shows how the area
changed from an inland site near a stony river some 17 000 years ago, to
a settlement on the coast when the sea rose about 7000 years ago. At this
stage the area became suitable for the development of mangroves. Remains
at the site show that the people living there reacted rapidly as conditions
Where previously they hunted inland species of animals, they now collected
shellfish and other species that live in mangroves. The supply of food was
richer and more people settled at the site. Then, 4000 years ago, the mangroves
silted up, the area became less productive, and people moved away in search
of new places to live.
Nearby, however, a freshwater swamp developed, and excavations of human
settlements there reveal the remains of freshwater plants and birds almost
contemporary with the development of the swamp. The correspondence between
the change in the environment and the remains at the site suggests that
people responded very quickly.
Yet although people changed their local habits, they kept their systems
of thought and culture, said Jones. The lesson from this, he said, is that
Aboriginal people had enough flexibility to overcome vast ecological change.
‘They remained an untransformed society in a changing landscape.’