The advance of prehistory

We are amazed at the new information coming out about old times.

One of our consultants was reading a history book recently and came upon a sentence beginning, “We shall never know. . .”  It struck him that such a saying is becoming increasingly ill-advised in any book on history or prehistory.  Now, it was an old book, from the middle of the last century, and the obscure bit of knowledge that it pronounced unknowable must have seemed safely lost by any reasonable measure.  But the absence of a direct record is less and less of a barrier to research, as new methods bring unexpected things to light.

Take one recent result.  The Polynesians, impressive navigators, had spread out from the Asian mainland and peopled all the Pacific islands up to Rapa Nui (Easter Island) centuries before any European sailors made an appearance there.  Well, did they make the final step and visit South America?  Or, as Thor Heyerdahl thought, did natives of South America visit the Pacific islands?  There are some similarities in culture and language that convince some people (and not others) that the two cultures came into contact.  Heyerdahl’s successful raft voyage from Peru to the Tuamotu Islands showed that it could be done, but not that it had been done.  In the absence of any material or documentary evidence, it appeared the question could not be answered.

Then a group ran a DNA analysis on Polynesians from various island groups and compared them with available data on South Americans.  In both there was a strong mixture of European genetic material, legacy of colonial days.  But they also found that a DNA sequence matching that of an indigenous people in present-day Columbia appeared in the Marquesas Islands about the time they were settled, roughly our year 1150.  This particular signal pointed to a single contact event, perhaps a lost fishing boat from the South American coast.  But it could also have been a voyage in the other direction.  We do not yet know enough to be sure.  Someday we may.

There have also been advances in dating.  For a long time the standard was carbon-14, a radioactive form of carbon whose decay time was well-known.  When properly calibrated, it could give you reliable dates out to possibly 50,000 years ago.  But it worked only if you had carbon.  A fireplace was an ideal location, or human or animal remains.  But not every site has these, or in the proper places to be useful.  The newer techniques of luminescence dating work with such inorganic materials as quartz and feldspar, and have been used to give a much better picture of a prehistoric site in Britain older than Stonehenge.

And there have been advances in ways of putting things together.  Data from archaeological sites across northern Europe has been combined with DNA data to give a social picture of the second and first millennium BC in the region, for which we have no written records at all.   There were long-range interactions, trade and marriage alliances, to match anything in the contemporary Minoan/Mycenaean Mediterranean.  And it looks like there was an battle in the Tollense Valley to match Homer in size and intensity.  It’s a shame we shall never recover the epic of the Battle at the Bridge.

Or maybe, someday. . .