万物简史 第620期:冰河时代(17)
What is most alarming is that we have no ideanonewhat natural phenomena could so swiftly rattle Earth's thermometer. As Elizabeth Kolbert, writing in the New Yorker, has observed: No known external force, or even any that has been hypothesized, seems
万物简史 第621期:冰河时代(18)
Climate is the product of so many variablesrising and falling carbon dioxide levels, the shifts of continents, solar activity, the stately wobbles of the Milankovitch cyclesthat it is as difficult to comprehend the events of the past as it is to pred
万物简史 第622期:冰河时代(19)
On the other hand, the next phase of our history could see us melting a lot of ice rather than making it. If all the ice sheets melted, sea levels would rise by two hundred feetthe height of a twenty-story buildingand every coastal city in the world
万物简史 第623期:神秘的两足动物(1)
THE MYSTERIOUS BIPED 第二十八章神秘的两足动物 Just before Christmas 1887, a young Dutch doctor with an un-Dutch name, Marie Eugene Francois Thomas Dubois, arrived in Sumatra, in the Dutch East Indies, with the intention of finding the ear
万物简史 第624期:神秘的两足动物(2)
At the time Dubois conceived his plan to search for a missing link, the human fossil record consisted of very little: five incomplete Neandertal skeletons, one partial jawbone of uncertain provenance, and a half-dozen ice-age humans recently found by
万物简史 第625期:神秘的两足动物(3)
Many people refused to accept that the Neandertal bones were ancient at all. August Mayer, a professor at the University of Bonn and a man of influence, insisted that the bones were merely those of a Mongolian Cossack soldier who had been wounded whi
万物简史 第626期:神秘的两足动物(4)
The next year Dubois's workers found a virtually complete thighbone that looked surprisingly modern. In fact, many anthropologists think itis modern, and has nothing to do with Java Man. If it is an erectus bone, it is unlike any other found since. N
万物简史 第627期:神秘的两足动物(5)
Meanwhile, and half a world away, in late 1924 Raymond Dart, the Australian-born head of anatomy at the University of the Witwatersrand in Johannesburg, was sent a small but remarkably complete skull of a child, with an intact face, a lower jaw, and
万物简史 第628期:神秘的两足动物(6)
Broom was an accomplished paleontologist, and since he was also resident in South Africa he was able to examine the Taung skull at first hand. He could see at once that it was as important as Dart supposed and spoke out vigorously on Dart's behalf, b
万物简史 第629期:神秘的两足动物(7)
At Black's urging, more determined excavations were undertaken and many other bones found. Unfortunately all were lost the day after the Japanese attack on Pearl Harbor in 1941 when a contingent of U.S. Marines, trying to spirit the bones (and themse
万物简史 第630期:神秘的两足动物(8)
In an attempt to introduce some order, in 1960 F. Clark Howell of the University of Chicago, following the suggestions of Ernst Mayr and others the previous decade, proposed cutting the number of genera to just twoAustralopithecus and Homo and ration
万物简史 第631期:神秘的两足动物(9)
Some continue to observe the two hominid genera suggested by Howell in 1960, but others place some of the australopithecines in a separate genus called Paranthropus , and still others add an earlier group called Ardipithecus. Some put praegens into A
万物简史 第632期:神秘的两足动物(10)
The shortage wouldn't be so bad if the bones were distributed evenly through time and space, but of course they are not. They appear randomly, often in the most tantalizing fashion. Homo erectus walked the Earth for well over a million years and inha
万物简史 第633期:神秘的两足动物(11)
It is the patchiness of the record that makes each new find look so sudden and distinct from all the others. If we had tens of thousands of skeletons distributed at regular intervals through the historical record, there would be appreciably more degr
万物简史 第634期:神秘的两足动物(12)
Finally, but perhaps above all, human nature is a factor in all this. Scientists have a natural tendency to interpret finds in the way that most flatters their stature. It is a rare paleontologist indeed who announces that he has found a cache of bon
