The co-evolution of human hands and tool using behaviour

当你和人们谈论人类与其他动物的不同之处时，他们很快就能认出的特征之一就是人的手。事实上，他们很可能将“对生拇指”视为人类独有的特征。虽然可以认为这不是严格正确的，但可以肯定的是，没有其他动物具有像人类那样精确控制双手的程度。我们理所当然地认为，单个手指的精细动作使我们能够弹钢琴或系鞋带，而这些活动是非人类不可能实现的。我们物种的进化史很可能与我们手的进化史密切相关，因此这是科学研究的一个重要领域。目前，我们对我们的手的形状是如何与那些密切相关的物种发生变化的了解很多，但我们实际上对这些形状的变化如何与手的功能联系在一起知之甚少。我们从黑猩猩和现代人类的共同祖先分化出来的故事包括用后肢行走、石器的创造、智力的提高以及在扩大的社会群体中生活。人类的手失去了运动的功能，使其能够专门操纵和感知世界，并扩大了其在交流中的作用，这一功能的变化成为一个引人注目的故事。特别是，我们双手的进化与我们使用越来越复杂的工具密切相关的观点似乎非常可信。因此，本研究项目的目的是探索人类手的功能能力的变化，并利用这些信息来评估手的进化史及其与工具使用和制造的关系。为了实现这一目标，我们需要收集关于人类手的各个部位是如何被使用的信息。这需要以一种可控的方式完成，这样我们就可以对不同动作的机械要求进行客观比较，我们可以将其与考古记录中的特定文物联系起来。因此，我们建议收集人类在执行这些任务时的运动和力量信息。我们将使用一系列为虚拟现实和电影特效开发的令人兴奋的新技术，在这些技术中，手和手指的运动可以通过使用特制的仪器手套和在手指上附加反射标记来自动记录。此外，仅仅记录这些信息不足以完全理解像手这样复杂的机制。我们还将利用医学成像和解剖的信息构建这些手和手臂运动的3D计算机模拟。然后，我们将使用各种复杂的机械工程技术来评估单个骨骼和肌肉在手部的功能。我们还需要评估人类手的功能是如何随着时间的推移而变化的，这意味着我们需要调查灵长类动物化石及其现存亲属的手。为了做到这一点，我们将为这些已经灭绝的物种创建等效的计算机模拟，这些模拟是根据化石骨骼重建的。计算机模型将使我们能够预测这些物种的能力，我们将能够直接评估我们最近的祖先在运动、觅食和工具使用能力方面的变化。

When you talk to people about what makes humans different from other animals, one of the features that they will rapidly identify is the human hand. Indeed they are very likely to identify the 'opposable thumb' as a uniquely human characteristic. Whilst it can be argued that this is not strictly true, it is certainly the case that there are no other animals that have anything like the degree of precise control of their hands that humans have. We take for granted the fine movements of individual fingers that allow us to play the piano or tie our shoelaces, and these are activities that are impossible for non-humans to achieve. It is likely that the evolutionary history of our species is very closely linked to the evolutionary history of our hands and this is therefore an important area for scientific study. We currently know a great deal about how the shape of our hands has changed from those of closely related species but we actually know very little about how these shape changes are linked to how the hand functions. The story of our divergence from the common ancestor of chimpanzees and modern humans includes walking on our hindlimbs, the creation of stone tools, the increase in our intelligence, and living in extended social groups. The change in function of the human hand by losing its locomotor role and allowing its specialisation for manipulating and sensing the world, and extending its role in communication becomes a compelling narrative. In particular the idea that the evolution of our hands is closely linked to our adoption of increasingly sophisticated tools seems extremely plausible.Thus the aim of this research project is to explore the changes in functional capabilities of the human hand and to use this information to evaluate the evolutionary history of the hand and its relationship to tool use and manufacture. To achieve this goal we need to collect information about how the individual parts of the hand are used in humans. This needs to be done in a controlled fashion so that we can make objective comparisons of the mechanical requirements of different actions that we can link to specific artifacts in the achaeological record. We therefore propose to collect movement and force information from humans whilst performing such a range of tasks. We will use a range of exciting new technologies developed for virtual reality and movie special effects where hand and finger movements can be recorded automatically using specially instrumented gloves and by attaching reflective markers to the fingers. In addition simply recording this information is insufficient to fully understand a mechanism as complex as a hand. We will also construct 3D computer simulations of these hand and arm movements using information from medical imaging and dissections. We will then use a variety of sophisticated mechanical engineering techniques to evaluate how the individual bones and muscles function within the hand. We also need to evaluate how human hand function has changed over time and this means that we need to investigate the hands of fossil primates as well as their living relatives. To do this we will create equivalent computer simulations for these extinct species reconstructed from the fossil bones. The computer models will allow us to predict the capabilities of these species and we will be able to directly evaluate the changes in locomotor, foraging and tool use capabilities of the hands of our closest ancestors over time.