2015复习正是强化复习阶段，在考研英语中占了40分，所以考研英语阅读是英语科目中重要的一项。名师老师曾建议过考研生需要坚持每天泛读10-15分钟的英文原刊。强烈推荐了杂志《经济学人》.杂志中的文章也是考研英语的主要材料来源.希望考研考生认真阅读，快速提高考研英语阅读水平。 The evolution of the hand 手的进化 Making a fist of it 拳头的演化 How a dual-use bodily structure came intoexistence 人手的双重功能如何生成 THE appendage at the end of a humanbeing s arm is a strange organ. 与人类手臂相连的手掌是一个奇特的部位，也是人类唯一因不同用途而拥有不同名称的部位。 It is the only one that has different names, depending on what it is being used for. Employ itto hold something, and it is called a hand. Employ it to hit someone, and it is called a fist. 拿物体，我们称之为手;攻击人，我们称之为拳头。 That second use, though, is almost unknown in other primates. 而几乎所有的灵长类动物极少使用拳头攻击。 Most primate hands are long of palm and finger, short of thumb, and suited for climbing. 大多数灵长类动物的手是手掌宽大、手指较长和大拇指较短，这一结构有利于攀爬。 Human hands have short palms, short fingers and long thumbs, which are not. 人类的手是手掌短小、手指适中和大拇指较长，这一结构不利于攀爬， These proportions do, though, make it possible to grip things in two ways that other apes hands cannot manage well. 然而，手的这种比例结构使得人类比其它灵长类动物更擅长于抓取物体，抓取有两种方式， One is by using what is known as a precision grip, in which an object is held between thepads of the finger tips and the pad of the thumb. 一是精确握法，使用大拇指指尖与其它手指指尖抓紧一物体; The other is by means of a power grip, in which all the fingers and the thumb are wrappedaround what is being grasped. 另一种方式是力量握法，包括大拇指在内的所有手指把一物体紧紧包住。 These two grips are crucial to Homo sapiens s characteristic tool-crafting skills, and it hasthus long been thought that the widespread use of tools by humanity s ancestors was thedriving force behind the modern hand s proportions. 以上两种握法是智人在使用工具上的关键特征，因此，长期以来人们认为人类的祖先广泛使用工具是驱使人类手部结构进化的推动力。 No doubt that was important. But a study just published in the Journal of ExperimentalBiology by Michael Morgan and David Carrier of the University of Utah has shown that theexact geometry of the hand is probably the result of its destructive rather than itsconstructive power. 毋庸置疑，广泛使用工具对人手的进化起到了重要的作用，但是，由犹他大学的生物学家迈克尔摩根与戴维卡里尔合作完成，并在最近刊登在《实验生物学杂志》的一篇论文里写道，人类手部的精确几何结构可能是破坏性力量导致的结果，非建设性力量导致的结果。 Most natural weapons are obvious: teeth, claws, antlers, horns. 诸如牙齿、爪子、鹿角、牛/羊角等大多数的天然武器是很直观的。 But the hand becomes a weapon only when it turns into a fist. 而手只有在变成拳头的时候才成为武器。 Dr Morgan and Dr Carrier therefore studied its anatomy to try to find out what makes the fistsuch an effective weaponone which, like the precision and power grips, the hand of evena chimpanzee is incapable of forming properly. 所以，摩根与卡里尔两位教授想通过解剖学来揭开拳头成为有效武器的之谜，其中包括连黑猩猩都做不到的精确握法与力量握法。 Part of the reason is obvious. 有一点是很明显的： A fist presents the knuckles first. 拳头是关节往外凸， That means the force of a blow is transmitted through a much smaller area than would be thecase for its alternative, an open-handed slap. 这意味着击打的接触面比掌击的接触面要小。 But the two researchers suspected that there might be more to it than that, so they dug alittle deeper. 但两位教授认为原因不仅仅如此，于是，他们进一步深入研究。 First, they gathered some basic measurements. 首先，摩根与卡里尔两位教授收集了一些基本的测量数据。 They asked ten athletesa mixture of boxers and martial artiststo strike a punch bag ashard as they could using either a normal fist or an open palm. 他们邀请了十位运动员，包括拳击手和格斗选手，要求他们用尽全力用拳头打沙袋或者掌击沙袋。 The athletes did so in many ways, including forward strikes, side strikes and overheadattacks, and Dr Morgan and Dr Carrier monitored how much force was delivered in each caseusing an accelerometer attached to the bag. 十位运动员以冲拳、测拳和高拳等方式击打沙袋。通过在沙袋上捆绑的加速计，两位教授监控到使用拳头打击或掌击在不同的击打方式下的力度。 They also used a series of pistons to measure the stiffness of different hand shapes. 除此之外，两位教授还使用了一系列的活塞来测量选手击打时手的不同姿势的硬度。 These included a fully clenched fist, a semi-fist with the fingers curled up but the thumbpointed outwards, and a poorly formed fist in which the fingers were folded over the palm andthe thumb pointed outwards. 这些姿势包括全握拳头、半握拳头以及虚拳。 As the athletes formed these various fists and fist-like shapes, the pistons measured therigidity of their hands along the knuckle bones. 从选手摆出手型准备出击到完成击打，活塞测量了他们手指关节的硬度。 Though the accelerometer in the punch bag suggested that a sideswipe made with a closedfist delivers 15% more force than an open-handed strike, a frontal attack with eitherproduces about the same force. 尽管在沙袋里的加速计的数据显示，拳击的近距离侧击比掌击能传递多15%的能量到沙袋上，但正面攻击沙袋时，无论是拳击还是掌击，传递到沙袋上的能量都差不多。 The fist s advantage thus seems to be mainly in its geometry rather than it mode ofdelivery. 由此看来，拳头的优势是得益于几何学而不是能量传递的方式。 Part of that advantage does, indeed, come from the small surface area of the knuckles. 拳头的指关节面积小，这是一个优势。 But the killer app, almost literally, is the stiffness imparted by the way the bones arearranged in a properly formed fist. 理论上，拳头的硬度源于手指骨组合方式的完美性。 This allows the force of a punch to be delivered with an effect that can, for the receiver, bebone breaking. 这样，力量能够以有效的方式传递至目标而不至于使手指骨断裂。 Two things are crucial. 有两个因素很关键。