from the BBC -

http://news.bbc.co.uk/2/hi/science/nature/5398850.stm

(text here in case the link dies --

Early humans followed the coast
By Paul Rincon
Science reporter, BBC News

Learning how to live off the sea may have played a key role in the
expansion of early humans around the globe.

After leaving Africa, human groups probably followed coastal routes to
the Americas and South-East Asia.

Professor Jon Erlandson says the maritime capabilities of ancient
humans have been greatly underestimated.

He has found evidence that early peoples in California pursued a
sophisticated seafaring lifestyle 10,000 years ago.

Anthropologists have long regarded the exploitation of marine
resources as a recent development in human history, and as peripheral
to the development of civilisation.

This view has been reinforced by a relative lack of evidence of
ancient occupation in coastal areas.

But that view is gradually changing; genetic studies, for example,
suggest a major early human expansion out of Africa occurred along the
southern coastline of Asia, leading to the colonisation of Australia
50,000 years ago.

Shifting sea levels since the last Ice Age, combined with coastal
erosion, would have erased many traces of a maritime past, Professor
Erlandson explained.

"The story of human evolution and human migrations has been dominated
by terrestrial perspectives," the University of Oregon researcher told
BBC News.

"I grew up on the coast and I always thought this didn't make much
sense. Coastlines are exceptionally rich in resources."

Ancient artefacts

Professor Erlandson has carried out extensive excavations on San
Miguel Island, off the coast of California, which is known to have
been inhabited at least 13,000 years ago.

About 100,000 seals and sea lions of six different species live on the
island. These slow-moving sea mammals would have been easy prey for
the island's early human inhabitants.

"The big elephant seals weigh over 3,000lbs," he explained. "It has
always seemed to me that these were a resource that early humans would
not want to miss."

One of the digs, at Daisy Cave, on San Miguel Island, has yielded
about 20 bone "gorges", a form of fish hook.

The gorges were covered with bait to be swallowed whole by fish, which
were then reeled in. These are between 8,600 and 9,600 years old and
are associated with more than 30,000 fish bones. They are the oldest
examples of such artefacts in the New World.

Actually proving such a migration took place is a very difficult
thing to do because of sea level changes and coastal erosion
Jon Erlandson, University of Oregon
The researchers have also recovered fragments of knotted "cordage" -
woven seagrass - that might have been used to make fishing nets. These
delicate items were preserved by pickling under layers of ancient
cormorant dung.

"The preservation is superb, so we interpreted the cordage as
'cut-offs' from the manufacture and maintenance of nets, fishing
lines, and other maritime-related woven technologies," Professor
Erlandson said.

At other sites, the researchers have found barbed points that were
most likely used for hunting sea mammals - possibly sea otters. They
also unearthed examples of 9,000-year-old basketry as well as
8,600-year-old shell bead jewellery.

'Kelp highway'

The findings from Daisy Cave could be consistent with the idea that
some of America's first colonists followed a coastal migration route
from Asia.

Conquering the cold waters of the northern Pacific would have required
advanced seafaring skills as well as an ability to successfully
exploit marine resources.

At the height of the last Ice Age, a land mass called Beringia would
have connected North-East Asia to North America.

Traditionally, the first Americans were thought to be big game
hunters, who marched from Siberia across the land bridge to Alaska.
Then, they were thought to have travelled south through the Canadian
Arctic via an "ice-free corridor" that emerged in the central US.

But the earliest signs of human occupation from the ice-free corridor
date to 11,000 years ago, while California's Channel Islands are now
known to have been inhabited at least 13,000 years ago.

Professor Erlandson has come up with an alternative theory that
maritime peoples from Asia followed forests of kelp to the New World.

Kelp Forest would have hugged the coastline from Japan up through
Siberia to Alaska and down along the Pacific coast of North America.
This marine plant grows in rocky, nearshore habitats and cold water up
to 20C.

It creates rich ecosystems, providing habitats for seals, sea otters,
hundreds of fish species and shellfish. These could have been
important sources of food and other resources such as skins for early
peoples.

However, the professor of archaeology says "actually proving such a
migration took place is a very difficult thing to do because of sea
level changes and coastal erosion".

He added: "I think the peopling of the New World was much more complex
than has traditionally been viewed. I think it probably involved
maritime and terrestrial migrations."

Jon Erlandson was speaking at the Calpe Conference 2006 in Gibraltar.