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it was so superior to existing tools that soon others were following the inventor’s lead andmaking hand axes of their own。 eventually whole societies existed that seemed to do littleelse。 “they made them in the thousands；” says ian tattersall。 “there are some places inafrica where you literally can’t move without stepping on them。 it’s strange because they arequite intensive objects to make。 it was as if they made them for the sheer pleasure of it。”
from a shelf in his sunny workroom tattersall took down an enormous cast； perhaps a footand a half long and eight inches wide at its widest point； and handed it to me。 it was shapedlike a spearhead； but one the size of a stepping…stone。 as a fiberglass cast it weighed only afew ounces； but the original； which was found in tanzania； weighed twenty…five pounds。 “itwas pletely useless as a tool；” tattersall said。 “it would have taken two people to lift itadequately； and even then it would have been exhausting to try to pound anything with it。”
“what was it used for then？”
tattersall gave a genial shrug； pleased at the mystery of it。 “no idea。 it must have had somesymbolic importance； but we can only guess what。”
the axes became known as acheulean tools； after st。 acheul； a suburb of amiens innorthern france； where the first examples were found in the nineteenth century； and contrastwith the older； simpler tools known as oldowan； originally found at olduvai gorge intanzania。 in older textbooks； oldowan tools are usually shown as blunt； rounded； hand…sizedstones。 in fact； paleoanthropologists now tend to believe that the tool part of oldowan rockswere the pieces flaked off these larger stones； which could then be used for cutting。
now here’s the mystery。 when early modern humans—the ones who would eventuallybee us—started to move out of africa something over a hundred thousand years ago；acheulean tools were the technology of choice。 these early homo sapiens loved theiracheulean tools； too。 they carried them vast distances。 sometimes they even took unshapedrocks with them to make into tools later on。 they were； in a word； devoted to the technology。
but although acheulean tools have been found throughout africa； europe； and western andcentral asia； they have almost never been found in the far east。 this is deeply puzzling。
in the 1940s a harvard paleontologist named hallum movius drew something called themovius line； dividing the side with acheulean tools from the one without。 the line runs in asoutheasterly direction across europe and the middle east to the vicinity of modern…daycalcutta and bangladesh。 beyond the movius line； across the whole of southeast asia andinto china； only the older； simpler oldowan tools have been found。 we know that homosapiens went far beyond this point； so why would they carry an advanced and treasured stonetechnology to the edge of the far east and then just abandon it？
“that troubled me for a long time；” recalls alan thorne of the australian nationaluniversity in canberra。 “the whole of modern anthropology was built round the idea thathumans came out of africa in two waves—a first wave of homo erectus； which became javaman and peking man and the like； and a later； more advanced wave of homo sapiens； whichdisplaced the first lot。 yet to accept that you must believe thathomo sapiens got so far withtheir more modern technology and then； for whatever reason； gave it up。 it was all verypuzzling； to say the least。”
as it turned out； there would be a great deal else to be puzzled about； and one of the mostpuzzling findings of all would e from thorne’s own part of the world； in the outback ofaustralia。 in 1968； a geologist named jim bowler was poking around on a long…dried lakebedcalled mungo in a parched and lonely corner of western new south wales when somethingvery unexpected caught his eye。 sticking out of a crescent…shaped sand ridge of a type knownas a lunette were some human bones。 at the time； it was believed that humans had been inaustralia for no more than 8；000 years； but mungo had been dry for 12；000 years。 so whatwas anyone doing in such an inhospitable place？
the answer； provided by carbon dating； was that the bones’ owner had lived there whenlake mungo was a much more agreeable habitat； a dozen miles long； full of water and fish；fringed by pleasant groves of casuarina trees。 to everyone’s astonishment； the bones turnedout to be 23；000 years old。 other bones found nearby were dated to as much as 60；000 years。
this was unexpected to the point of seeming practically impossible。 at no time sincehominids first arose on earth has australia not been an island。 any human beings who arrivedthere must have e by sea； in large enough numbers to start a breeding population； aftercrossing sixty miles or more of open water without having any way of knowing that aconvenient landfall awaited them。 having landed； the mungo people had then found their waymore than two thousand miles inland from australia’s north coast—the presumed point ofentry—which suggests； according to a report in the proceedings of the national academy ofsciences； “that people may have first arrived substantially earlier than 60；000 years ago。”
how they got there and why they came are questions that can’t be answered。 according tomost anthropology texts； there’s no evidence that people could even speak 60；000 years ago；much less engage in the sorts of cooperative efforts necessary to build ocean…worthy craft andcolonize island continents。
“there’s just a whole lot we don’t know about the movements of people before recordedhistory；” alan thorne told me when i met him in canberra。 “do you know that whennineteenth…century anthropologists first got to papua new guinea； they found people in thehighlands of the interior； in some of the most inaccessible terrain on earth； growing sweetpotatoes。 sweet potatoes are native to south america。 so how did they get to papua newguinea？ we don’t know。 don’t have the faintest idea。 but what is certain is that people havebeen moving around with considerable assuredness for longer than traditionally thought； andalmost certainly sharing genes as well as information。”
the problem； as e