GWD-31-Q20-Q23 求助！ 对这篇文章的逻辑有疑惑，非常大的疑惑！！！

wxeshirley

GWD-31-Q20-Q23
人直立行走

         Anthropologistsonce thought that the ancestors of modern humans began to walk upright becauseit freed their hands to use stone tools, which they had begun to make as thespecies evolved a brain of increased size and mental capacity. But discoveriesof the three-million-year-old fossilized remains of our hominid ancestorAustralopithecus have yielded substantial anatomical evidence that uprightwalking appeared prior to the dramatic enlargement of the brain and thedevelopment of stone tools.

       Walking on two legs in an uprightposture (bipedal locomotion) is a less efficient proposition than walking onall fours (quadrupedal locomotion) because several muscle groups that thequadruped uses for propulsion must instead to provide the biped with stability andcontrol. The shape and configuration of various bones must likewise be modifiedto allow the muscles to perform these functions in upright walking.Reconstruction of the pelvis (hipbones) and femur (thighbone) of “Lucy”, athree-million-year-old skeleton that is the most complete fossilized skeletonfrom the australopithecine era, has shown that they are much more like thecorresponding bones of the modern human than like those of the most closelyrelated living primate, the quadrupedal chimpanzee. Lucy’s wide, shallow pelvisis actually better suited to bipedal walking than is the rounder, bowl-likepelvis of the modern human, which evolved to form the larger birth canal neededto accommodate the head of a large-brained human infant. By contrast, the headof Lucy’s baby could have been no larger than that of a baby chimpanzee.

     If the small-brained australopithecines werenot toolmakers, what evolutionary advantage did they gain by walking upright? One theory is that bipedalityevolved in conjunction with the nuclear family: monogamous parents cooperatingto care for their offspring. Walking upright permitted the father to usehis hands to gather food and carry it to his mate from a distance, allowing themother to devote more time and energy to nurturing and protecting theirchildren. According to this view, the transition to bipedal walking may haveoccurred as long as ten million years ago, at the time of the earliesthominids, making it a crucial initiating event in human evolution.

题目没有疑问，但是文章的逻辑总觉有矛盾，问题主要出在对highlight 的地方的理解上。

我说一下自己的理解：

从第一段的once thought 的连接词becasuse 和 后面的过去完成时都可以看出原先的观点是直立行走发生在使用工具之后，而大脑的发育是发生在使用工具之前的。这里没有问题。

最后一段第一句提了个问题，肯定不能没来由地提问啊，应该是承接前文而来的。就是这个问题搞得我一头雾水。

作者问“如果小脑的古人不能使用工具，那么直立行走的意义在哪里？” 我理解这句话应该不是个简单的问句“如果某种情况没有出现，那么有什么其他的情况呢？”它比较像一句让步“既然某种情况已经是不可能的了，那么有没有其他的解释呢”， 有点像我们写作文的时候前面反驳了一些事实，然后为了引出我们自己的观点写的一个承上启下的句子。

按照这种理解，这句话应该暗含下面这个意思，即原来有某些观点认为直立行走的意义是使人能够使用工具啊， 但是这样的话不就意味着原来认为直立行走发生在使用工具之前了吗，这不就和once thought 那里矛盾了吗？？

不知道有没有人看得懂我这大长篇，我觉得可能对文章的某些小词理解有点偏差，或者加入了太多自己的理解（比如最后一个问句可能就只是一个简单的问句。。。。），但是想来想去还是觉得有问题。。。哪个朋友来解释一下。很多时候我看文章都会有这种揣测句子在整篇文章的逻辑意思然后推断作者的观点的倾向（自热而然地读过去然后就在脑子里整合），有时候和作者的思路一样做起题来百发百中，有时候看漏了关键词然后思路偏了做题就错。。。但是这篇是对作者的逻辑理解无能了。