达尔文的原创

Darwin’s Originality

Peter J. Bowler. Darwin’s Originality. Science 323, 223-226 (2009)


1、进化的观点并不是达尔文的原创，但是进化的机制却是由达尔文首先提出的。


2、在达尔文进化论提出之前被人们普遍接受的是“目的论”Most thinkers—including Jean-Baptiste Lamarck and Chambers—took it for granted that the development of life on earth represents the unfolding of a coherent plan aimed at a predetermined goal. (This assumption is still preserved in the very term “evolution”; the Latin evolutio refers to the unrolling of a scroll.)


3、达尔文认为：生物对环境的适应是引起变异的唯一原因。通过生存竞争实现自然选择使生物适应环境。


4、变异是没有方向的，物种是由不断变化的个体组成的群体。Species had to be treated as populations of varying individuals, with no fixed limit on the range of possible variation.


5、进化是一个不断分离的过程，有一些分支继续分离，另一些分支走到尽头而灭绝。亲缘近的物种分离晚，亲缘远的物种分离早。这就是“共同起源学说”。这一学说现在看起来是显而易见的，但历史上也有其它解释物种起源的学说提出，如
William Sharp Macleay 的circular system of classification：every genus contained five species that could be arranged in a circle; each family five genera, and so on through the taxonomic hierarchy
Chambers 的 parallel lines advancing：through a predetermined sequence of stages within each family, driven by force derived from individual development.


6、达尔文进化论的提出是受德国浪漫主义影响、Beagle voyage和对奴隶制度的憎恨


7、人工选择实验是自然选择法则的最好证明，达尔文发现在一个驯养群体中总是存在着不同的变异，说明变异是没有方向的。


8、物种是一个独立繁殖系，而不是一个形态标准。the species is just a population of interbreeding individuals. Traditionally, species were treated as idealized types with a fixed essence, any variation from the norm being trivial and impermanent.



9、生存斗争法则的提出给纳粹分子的思想提供了依据。But by proposing that evolution worked
primarily through the elimination of useless variants, Darwin created an image that could all too easily be exploited by those who wanted the human race to conform to their own preexisting ideals.