物竞天择是如何发挥作用的？

What’s Natural Selection and how it works? E.g. does natural selection refer to a group of random process? How does natural selection work on human beings? Does this process against emotions and cultures evolved in human and broader animal communities? Does natural selection only work on physical or it also work on mental as well?

什么是物竞天择理论，它又是如何发挥作用的呢？例如物竞天择指的是一系列随机偶然的进化过程吗？物竞天择对人类又是如何发挥作用的？人类或者更广泛的动物群体中涉及的思绪情感和文化是否不受物竞天择这一过程的支配和影响？物竞天择理论究竟是只在自然物质方面起作用呢还是也在精神方面起作用？

Natural selection is a process that may lead to the origin of new species. It requires that there is competition for resources, variation in the attributes of individuals of a particular species, and heritability of those attributes from generation to generation.

物竞天择是一个可以致使新物种产生的过程。它需要具备以下条件：存在对各种资源的竞争、某一特定物种的不同个体在各种属性上存在差异以及这些属性具有代代相传的遗传性。

It is the genes possessed by an individual that largely determine its particular attributes and also allow most of these attributes to be passed on to its offspring. An animal’s particular attributes will determine its ability to successfully mate and have offspring in its local environment (its “fitness”). As there is variation in attributes between individuals, the “fittest” individuals will pass on more genes to the next generation than others. As the process is determined by the interaction of organisms and their environment it is not strictly random. However, chance events, such as asteroid impact can radically alter the environment and thus change which individuals are best adapted to pass on their genes, and thus the fittest. The process does not require divine intervention to operate.

某个体的特定属性在很大程度上是由该个体拥有的基因所决定的，同时基因也使得这些特定属性可以传递给后代。某种动物的特定属性将决定它成功交配并在生存环境中孕育后代的能力（它的“适应性”）。由于不同个体的属性存在差异，那么“最适应”的个体将比其他个体传递更多的基因给下一代。由于这一过程是由生物体及其所在环境的相互作用而决定的，因此它并非具有严格的随机性。但是，一些偶然事件，比如小行星撞击地球可以彻底改变生存环境，从而会改变哪些个体最适应环境来传递基因，进而使其成为“最适应”的个体。这一过程的运用并不需要神灵的干预。

For the past few hundred years humans have been under reduced natural selection because after advances in sanitation, plumbing, and some aspects of medicine they have a lot of power over their own environment. Most individuals have the opportunity to have children. Nevertheless, a clear example of natural selection operating in humans is the higher frequency of sickle cell anaemia in geographic areas with malaria. Sickle cell anaemia fully expressed is very disadvantageous but individuals with the genes from only one parent have protection from malaria which is potentially more lethal.

在过去的几百年中，人类受到物竞天择理论的影响已经减弱，因为在环境卫生、饮水设施以及医疗条件的方方面面已经得到大大的改善之后，人类对于自己所生存的环境有了很强的控制力。大多数的人类个体有机会孕育子孙后代。然而，物竞天择理论对人类仍然发挥作用的一个最典型的例子就是在疟疾横行的地区更容易出现镰状细胞贫血症。镰状细胞贫血如果被完全传递给后代那是相当不利的，但是如果父母双方只有一方将该基因传递给后代，那么这些后代个体对于更加致命的疟疾就会产生抗体。

It has been argued that “ideas” and “culture” are subject to a process similar to natural selection. This is because there is variation between ideas, competition between ideas and ideas can be passed on from one generation to the next by word of mouth, writing, or audio and visual media. 一直以来，人们都在争辩，“思想观念”和“文化”是否被某个类似物竞天择的过程所支配。因为思想观念之间存在差异、不同的思想观念之间存在竞争，并且思想观念还可以通过口口相传、书面文字或者音频视频媒体传递给下一代。

马克·琼斯博士作者简介：

Marc is currently a BBSRC postdoctoral researcher at UCL, University College London, UK. His research focuses mainly on skull mechanics and feeding apparatus in reptiles such as the New Zealand tuatara (Sphenodon). However, he has a wide variety of interests including the evolution and diversification of modern amphibians such as frogs, statistical shape analysis, the biogeography of southern continents, and imaging specimen data. As well as carrying out research Marc occasionally teaches zoology and human anatomy. In his spare time he enjoys films, art galleries and life drawing. He is a native Welsh speaker. See: http://www.cdb.ucl.ac.uk/research/evans/jones.shtml

马克博士目前作为一名生物工程与生物学研究协会（BBSRC）研究员工作于英国伦敦大学学院。他的研究领域主要集中于头骨力学以及爬行动物的进食方式，例如新西兰大鳄蜥。同时，他对于其他近现代的两栖动物的进化研究也有着浓厚的兴趣，包括青蛙，统计形状分析，南部大陆生物地理学，数据和图像标本等等。马克博士在从事研究工作的同时也在伦敦大学学院担任临时客座动物学与人体解剖学讲师。在业务时间里，马克博士喜欢电影，艺术博物馆以及绘画。同时，他可以讲一口地道的威尔士语。希望更多的了解马克博士以及他的工作可以访问：http://www.cdb.ucl.ac.uk/research/evans/jones.shtml

(本文来源：网易探索 作者：马克·琼斯)