Environmental setting of human migrations in the circum-Pacific region

To assess the genetic and archaeological evidence for
the migration of modern humans out of Africa to the
circum-Pacific region and compare the migration patterns
with Late Pleistocene and Holocene changes in sea level
and climate.


*Location
Southern and eastern Asia, Australia, and Oceania.


*Methods
Review of the literature and detailed compilations of data
on early human settlements, sea level, and climate
change.


*Results
The expansion of modern humans out of Africa, following
a coastal route into southern Asia, was initially thwarted
by a series of large and abrupt environmental changes. A
period of relatively stable climate and sea level from c.
45,000 yr bp to 40,000 yr bp supported a rapid coastal
expansion of modern humans throughout much of
Southeast Asia, enabling them to reach the coasts of
northeast Russia and Japan by 38,000–37,000 yr bp.
Further northwards, migrations were delayed by cold
northern climates, which began to deteriorate rapidly after
33,000 yr bp.


Human migrations along the coast of the Bering Sea into
the New World appear to have occurred much later, c.
14,000 yr bp, probably by people from central Asia who
were better adapted to cold northern climates. Cold, dry
climates and rapidly changing sea levels leading into and
out of the Last Glacial Maximum inhibited coastal
settlement, and many of the sites occupied prior to
33,000 yr bp were abandoned.


After 16,000 yr bp, the sea-level rise slowed enough to
permit coastal ecosystems to develop and coasts to be
re-colonized, but abrupt changes in climate and sea level
inhibited this development until after 12,000 yr bp.
Between 12,000 yr bp and 7000 yr bp there was a
dramatic increase in reef and estuary/lagoon
ecosystems, concurrent with a major expansion of
coastal settlements.


This early Holocene increase in coastal environments and
the concomitant expansion of human coastal-resource
exploitation were followed by corresponding declines in
both phenomena in the mid-Holocene, c. 6000–4000 yr
bp. This decline in coastal resources is linked to the drop
in sea level throughout the Pacific, which may have
caused the widespread population dislocations that
ultimately led to the human expansion throughout
Oceania.


*Main conclusions
Climate and sea-level changes played a central role in
the peopling of the circum-Pacific region."

Full Article:


Environmental setting of human migrations in the circum-Pacific region

Environmental setting of human migrations in the circum-Pacific region