TOEFL Reading Comprehension Section (2)

COLONIZING THE AMERICAS VIA THE NORTHWEST COAST

It has long been accepted that the Americas were colonized by a migration of
peoples from Asia slowly traveling across a land bridge called Beringia (now the Bering Strait
between northeastern Asia and Alaska) during the last Ice Age. The first water craft theory
about this migration was that around 11,000-12,000 years ago there was an ice-free corridor
stretching from eastern Beringia to the areas of North America south of the great northern
glaciers. It was this midcontinental corridor between two massive ice sheets—the Laurentide
to the east and the Cordilleran to the west—that enabled the southward migration. But belief

In this ice-free corridor began to crumble when paleoecologist Glen MacDonald demon-
strated that some of the most important radiocarbon dates used to support the existence of

an ice-free corridor were incorrect. He persuasively argued that such an ice-free corridor did
not exist until much later, when the continental ice began its final retreat.
Support is growing for the alternative theory that people using watercraft, possibly
skin boats, moved southward from BerIngla along the Gulf of Alaska and then southward
along the Northwest Coast of North America possibly as early as 16,000 years ago.
This route would have enabled humans to enter southern areas of the Americas prior
to the melting of the continental glaciers. Until the early 1970s, most archaeologists

did not consider the coast a possible migration route into the Americas because geol-
ogists originally believed that during the last Ice Age the entire Northwest Coast was

covered by glacial ice. It had been assumed that the ice extended westward from the

Alaskan/Canadian mountains to the very edge of the continental shelf—the flat, sub-
merged part of the continent that extends into the ocean. This would have created

a barrier of ice extending from the Alaska Peninsula, through the Gulf of Alaska and
southward along the Northwest Coast of North America to what Is today the state of
Washington.

A
A
0
A
1
The most influential proponent of the coastal migration route has been Canadian
archaeologist Knut Fladmark. He theorized that with the use of watercraft, people
gradually colonized unglaciated refuges and areas along the continental shelf exposed
by the lower sea level. Fladmark's hypothesis received additional support from the
fact that the greatest diversity In Native American languages occurs along the west
coast of the Americas, suggesting that this region has been settled the longest.

More recent geologic studies documented deglaciation and the existence of ice-
free areas throughout major coastal areas of British Columbia, Canada, by 13,000 years

ago. Research now indicates that sizable areas of southeastern Alaska along the inner
continental shelf were not covered by ice toward the end of the last Ice Age. One study
suggests that except for a 250-mile coastal area between southwestern British Columbia
and Washington State, the Northwest Coast of North America was largely free of ice by
approximately 16,000 years ago. Vast areas along the coast may have been deglaciated

beginning around 16,000 years ago, possibly providing a coastal corridor for the move-
ment of plants, animals, and humans sometime between 13,000 and 14,000 years ago.

The coastal hypothesis has gained increasing support in recent years because
the remains of large land animals, such as caribou and brown bears, have been found
in southeastern Alaska dating between 10,000 and 12,500 years ago. This is the
time period in which most scientists formerly believed the area to be inhospitable

for humans. It has been suggested that if the environment were capable of support-
ing breeding populations of bears, there would have been enough food resources

to support humans. Fladmark and others believe that the first human colonization of
America occurred by boat along the Northwest Coast during the very late Ice Age,
possibly as early as 14,000 years ago. The most recent geologic evidence indicates

that it may have been possible for people to colonize ice-free regions along the con-
tinental shelf that were still exposed by the lower sea level between 13,000 and

14,000 years ago.
The coastal hypothesis suggests an economy based on marine mammal hunting,
saltwater fishing, shellfish gathering, and the use of watercraft. Because of the barrier
of ice to the east, the Pacific Ocean to the west, and populated areas to the north, there
may have been a greater impetus for people to move in a southerly direction.

Directions: Now answer the questions.

It has long been accepted that the Americas were colonized by a migration of peo-
ples from Asia, slowly traveling across a land bridge called Beringia (now the Bering Strait

between northeastern Asia and Alaska) during the last Ice Age. The first water craft theory
about this migration was that around 11,000-12,000 years ago there was an Ice-free corridor
stretching from eastern Beringia to the areas of North America south of the great northern
glaciers. It was this midcontinental corridor between two massive ice sheets—the Laurentide
to the east and the Cordilleran to the west—that enabled the southward migration. But

belief in this ice-free corridor began to crumble when paleoecologist Glen MacDonald dem-
onstrated that some of the most important radiocarbon dates used to support the existence

of an ice-free corridor were Incorrect. He persuasively argued that such an ice-free corridor
did not exist until much later, when the continental ice began its final retreat.

Support is growing for the alternative theory that people using watercraft, possibly

skin boats, moved southward from Beringia along the Gulf of Alaska and then south-
ward along the Northwest Coast of North America possibly as early as 16,000 years ago.

This route would have enabled humans to enter southern areas of the Americas prior to
the melting of the continental glaciers. Until the early 1970s, most archaeologists did
not consider the coast a possible migration route into the Americas because geologists
originally believed that during the last Ice Age the entire Northwest Coast was covered
by glacial ice. It had been assumed that the ice extended westward from the Alaskan/
Canadian mountains to the very edge of the continental shelf—the flat, submerged part
of the continent that extends into the ocean. This would have created a barrier of ice
extending from the Alaska Peninsula, through the Gulf of Alaska and southward along
the Northwest Coast of North America to what Is today the state of Washington.

The most influential proponent of the coastal migration route has been Canadian

archaeologist Knut Fladmark. He theorized that with the use of watercraft, people gradu-
ally colonized unglaciated refuges and areas along the continental shelf exposed by the

lower sea level. Fladmark's hypothesis received additional support from the fact that
the greatest diversity in Native American languages occurs along the west coast of the
Americas suggesting that this region has been settled the longest.

More recent geologic studies documented deglaciation and the existence of ice-free
areas throughout the major coastal areas of British Columbia, Canada, by 13,000 years
ago. Research now indicates that sizable areas of southeastern Alaska along the inner
continental shelf were not covered by ice toward the end of the last Ice Age. One study
suggests that except for a 250-mile coastal area between southwestern British Columbia
and Washington State, the Northwest Coast of North America was largely free of ice by
approximately 16,000 years ago. Vast areas along the coast may have been deglaciated

beginning around 16,000 years ago, possibly providing a coastal corridor for the move-
ment of plants, animals, and humans sometime between 13,000 and 14,000 years ago.

The coastal hypothesis has gained increasing support in recent years because the
remains of large land animals, such as caribou and brown bears, have been found in
southeastern Alaska dating between 10,000 and 12,500 years ago. This is the time
period in which most scientists formerly believed the area to be inhospitable for humans.

It has been suggested that if the environment were capable of supporting breeding pop-
ulations of bears, there would have been enough food resources to support humans.

Fladmark and others believe that the first human colonization of America occurred by
boat along the Northwest Coast during the very late Ice Age, possibly as early as 14,000
years ago. The most recent geologic evidence indicates that it may have been possible
for people to colonize ice-free regions along the continental shelf that were still exposed
by the lower sea level between 13,000 and 14,000 years ago.

It has long been accepted that the Americas were colonized by a migration of
peoples from Asia slowly traveling across a land bridge called Beringia (now the Bering
Strait between northeastern Asia and Alaska) during the last Ice Age. (A) The first water
craft theory about this migration was that around 11,000-12,000 years ago there was an
ice-free corridor stretching from eastern Beringia to the areas of North America south
of the great northern glaciers. It was this midcontinental corridor between two massive
ice sheets—the Laurentide to the east and the Cordilleran to the west—that enabled
the southward migration. (13) But belief in this ice-free corridor began to crumble when

paleoecologist Glen MacDonald demonstrated that some of the most important radio-
carbon dates used to support the existence of an ice-free corridor were incorrect. (C) He

persuasively argued that such an ice-free corridor did not exist until much later, when the
continental ice began its final retreat. (D)