The story as conventionally told (or at least as frequently remembered by many of us) is that Darwin, while traveling from island to island, noticed that the finches' beaks on each island were marvelously adapted for exploiting local resources — that on one island beaks were sturdy and short and good for cracking nuts, while on the next island beaks were perhaps long and thin and well suited for winkling food out of crevices — and it was this that set him to thinking that perhaps the birds had not been created this way, but had in a sense created themselves.
通常的说法是（至少在我们许多人的记忆里通常是这样的），当他一个岛一个岛旅行时，达尔文注意到每个岛上的效舌鸫都非常适宜利用当地的资源——一个岛上的效舌鸫的嘴又短又坚固，适宜啄开坚果；到了下一个岛屿，效舌鸫的嘴也许又长又尖，适宜在岩缝中啄玉黍螺——正是这种现象使得他开始想到，也许这些鸟并不是生来就是这样，而是在某种程度上自己造成了这样。

In fact, the birds had created themselves, but it wasn't Darwin who noticed it. At the time of the Beagle voyage, Darwin was fresh out of college and not yet an accomplished naturalist and so failed to see that the Galapagos birds were all of a type. It was his friend the ornithologist John Gould who realized that what Darwin had found was lots of finches with different talents. Unfortunately, in his inexperience Darwin had not noted which birds came from which islands. (He had made a similar error with tortoises.) It took years to sort the muddles out.
事实上，确实是鸟类创造了它们自己，不过注意到这一点的并不是达尔文。在随“贝格尔”号远航时，达尔文是一个初出校园的学生，不是训练有素的博物学家，因此他并没有注意到加拉帕戈斯的鸟类全都属于同一类型。是达尔文的朋友——鸟类学家约翰·古尔德意识到，达尔文发现的不过是具有不同本事的效舌鸫。不幸的是，由于没有经验，达尔文并没有注意到这些鸟分别来自加拉帕戈斯群岛的哪一个岛屿。（他在观察乌龟时犯了同样的错误。）清理这种混乱状态让他花费了好多年的时间。
Because of these oversights, and the need to sort through crates and crates of other Beagle specimens, it wasn't until 1842, six years after his return to England, that Darwin finally began to sketch out the rudiments of his new theory. These he expanded into a 230-page "sketch" two years later.
由于类似这样的种种疏忽，同时也由于需要将“贝格尔”号带回的成箱成箱的标本加以分门别类，直到l842年，在回到英国之后的第5年，达尔文才最终草拟出他的新理论的雏形。两年后，他将他的新理论进一步扩充成230页的“概要”。