By Chris Catling, January 6, 2012.From issue 51, page 11
The idea that the early humans who migrated to South-east Asia and on to
Australia 50,000 or more years ago lacked the skills to build boats has
been dealt a blow by evidence for deep-sea fishing 42,000 years ago.
Researchers from the Australian National University (ANU) in Canberra have
found 38,000 fish bones from 2,843 individual fish dating back to the 40th
millennium in the Jerimalai cave at the eastern end of the island of East
Crucially, about half of the fish in the oldest cave strata are fast-swimming
pelagic (or deep-sea) fish species, such as shark and tuna, that are very
difficult to catch in inshore waters using nets or spears.
The team, which is led by ANU professor Susan O'Connor, also found a fishhook
fragment at Jerimalai made from a mollusc shell, and dated to between 23,000
and 16,000 years ago. Writing about the find in the journal Science, O'Connor
says that the hook would have been attached to a line and baited, and may
have been used in deep-water fishing, though it would probably not have been
suitable for catching fast-moving pelagic species such as tuna. It is evidence,
however, that ancient people had the necessary craft skills to make other
types of hooks.
Even though sea levels were significantly lower 50,000 years ago, the
colonisation of Australia and nearby islands would still have required sea
crossings of at least 30km; but whether early migrants could build boats or
whether they simply drifted on logs or crudely made rafts, is still a matter
of fierce debate. Professor O'Connor admits to having been a sceptic herself
at one time, simply because direct evidence for early boat-building skills has
been lacking: the earliest surviving boats are a mere 10,000 years old, and no
bones from deep-water fish have previously been found that are more than
20,000 years old. She now believes the finds from Jerimalai indicate that
prehistoric migrants had high-level maritime skills and, by implication, the
technology needed to make the sea crossings to reach Indonesia, Papua New
Guinea, and Australia.