Biology Reference
In-Depth Information
2
Location, Location, Location
Nomads pursuing herds of migrating animals across the frozen
landscape connecting present-day Siberian Russia with Alaska
were the fi rst to glimpse the New World. The Bering Land Bridge
was accessible to varying extents during the latter part of the Ter-
tiary period; and with the onset of eighteen to twenty glacial cycles
during the 2.6 million years of the Quaternary period, sea levels
periodically dropped by about 120 m, providing a continuous con-
nection over 1500 miles wide. The most recent connection was
around 17 kyr near the end of the LGM. Although conditions must
have been horrendous, ice-free pathways did exist, and for a no-
madic people depending on hunting, there was little choice but to
follow the migrating herds as they had done for generations. The
footprints are blurred, and the itinerary unsettled, but people of
Asian origin did enter the New World through Beringia by 15 kyr.
Their descendents had established the Clovis Culture at Murray
Springs, Arizona, by 13.5 kyr, as evident by the bones of bison
and mammoth associated with Clovis Point arrowheads (fi g. 2.1).
