If new species were continuously evolving, then there ought to be lots of intermediate forms scattered across the fossil record, but there were not. In fact, the record as it existed then (and for a long time afterward) showed no life at all right up to the moment of the famous Cambrian explosion. (By coincidence, in 1861, at the height of the controversy, just such evidence turned up when workers in Bavaria found the bones of an ancient archaeopteryx, a creature halfway between a bird and a dinosaur. (It had feathers, but it also had teeth.) It was an impressive and helpful find, and its significance much debated, but a single discovery could hardly be considered conclusive.)
如果物种是持续不断地进化的，那么在化石中一定存在不少进化过程中的中间形态，但是事实上却没有。其实，当时（及以后很多年）已发现的化石表明，一直到著名的寒武纪大爆发之前，地球上根本没有任何生命。（注：巧合的是，1861年，就在争论最为激烈的时候，一个这样的证据出现了。工人们在巴伐利亚发现了几根古代始祖鸟的骨头，这是一种介于鸟和恐龙之间的动物。（它有羽毛，但也有牙齿。）这一发现令人印象深刻，同时也很有帮助，其特征被广泛地加以讨论，但是一个单独的发现几乎很难得出肯定的结论。）

But now here was Darwin, without any evidence, insisting that the earlier seas must have had abundant life and that we just hadn't found it yet because, for whatever reason, it hadn't been preserved. It simply could not be otherwise, Darwin maintained. "The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained," he allowed most candidly, but he refused to entertain an alternative possibility. By way of explanation he speculated — inventively but incorrectly — that perhaps the Precambrian seas had been too clear to lay down sediments and thus had preserved no fossils.
而在没有任何证据的情况下，达尔文却坚持认为早期的海洋里一定存在着丰富多彩的生命形式，只是我们还没有找到它们而已。这是因为，不论出于何种原因，它们并没有保存下来。达尔文认为这是惟一合理的解释。“这种情形现阶段肯定无法解释清楚，但可以尽量被看做起与现存看法相对立的合理观点。”他很直率地承认，但是拒绝考虑其他可能性。为了解释，他推论说——富有创见，却是不正确的，也许前寒武纪的海水太清澈了，不能沉淀下任何物质，因此也就没有将化石保存下来。
Even Darwin's closest friends were troubled by the blitheness of some of his assertions. Adam Sedgwick, who had taught Darwin at Cambridge and taken him on a geological tour of Wales in 1831, said the book gave him "more pain than pleasure."
即使是达尔文最好的朋友，也对他的某些过于武断的结论感到不安，亚当·塞奇威克是达尔文在剑桥大学的老师，l887年曾带他到威尔士作地质考察，他说达尔文的书给他的“痛苦多于快乐”。