but in nearly every edition of Origin he stepped up the amount of time he supposed necessary to allow evolution to progress, 而且几乎《物种起源》的每次重版，他都要将他所认为的进化过程所需的时间长度增加一些，这导致了他的支持者的强烈反感，

which pushed his ideas increasingly out of favor. 支持他理论的人越来越少。

"Eventually," according to the scientist and historian Jeffrey Schwartz, “最后，”根据科学家兼历史学家杰弗里·施瓦兹的说法，

"Darwin lost virtually all the support that still remained among the ranks of fellow natural historians and geologists." “达尔文在自然史和地质学家同行那里仅有的支持也丢失殆尽了。”

Ironically, considering that Darwin called his book On the Origin of Species, 具有讽刺意味的是，达尔文将他的书取名为《物种起源》，

the one thing he couldn't explain was how species originated. 可是对物种是怎样起源的，他却不能作出解释。

Darwin's theory suggested a mechanism for how a species might become stronger or better or faster — in a word, fitter, 达尔文的理论暗示了一种使得一个物种怎样变得更强、更好或更快——一句话，更适应，

but gave no indication of how it might throw up a new species. 的机制，但却没有说明新的物种是怎样诞生的。

A Scottish engineer, Fleeming Jenkin, considered the problem and noted an important flaw in Darwin's argument. 苏格兰工程师弗莱明·詹金思考了这个问题，指出达尔文的论点中的一个严重缺陷。

Darwin believed that any beneficial trait that arose in one generation would be passed on to subsequent generations, thus strengthening the species. 达尔文认为某一代物种中出现的（有利的）特性都会传给下一代，并从而使该物种更加强健。

Jenkin pointed out that a favorable trait in one parent wouldn't become dominant in succeeding generations, 詹金指出，上一代中的（有利的）特性在遗传给下一代时，不会在随后的几代中占主导地位，

but in fact would be diluted through blending. 而实际上是在混合过程中被冲淡了。

If you pour whiskey into a tumbler of water, you don't make the whiskey stronger, you make it weaker. 如果你往威土忌中倒进一杯水，你不会使威士忌变得更浓，而是将其稀释了；

And if you pour that dilute solution into another glass of water, it becomes weaker still. 如果你再往已稀释的威士忌中倒进一杯水，威士忌会变得更淡。

In the same way, any favorable trait introduced by one parent would be successively watered down by subsequent matings until it ceased to be apparent at all. 同样，上一代父母遗传给下一代的有利特性在随后的不断繁殖中会被逐渐削弱，直到最后完全消失。