当时的达尔文推诿于化石记录的不完整。经过一百多年的努力，科学家们已发现许多保存相当完整的地层，对其中所保存的化石也作了深入而系统的研究，可是中间类型的化石仍难寻获。

美国哈佛大学古生物学教授古尔德（Stephen Jay Gould）评估了化石记录，并提出了“间断平衡”理论（下文讨论）。法学教授菲利普‧E‧约翰逊（Phillip E. Johnson）在其著作《审判达尔文》中这样总结了古尔德的工作：“如果进化的要意是解释一种生物可以渐渐改变成为另一种生物，那么化石的显著特征就是证明了进化没有证据。”（In short, if evolution means the gradual change of one kind of organism into another kind, the outstanding characteristic of the fossil record is the absence of evidence for evolution.）⁷⁸

英国古生物学家、化石研究权威专家科林‧帕特森博士（Colin Patterson, 1933—1998）⁷⁹，于1962至1993年在伦敦自然历史博物馆（Natural History Museum）工作。1981年他在一次美国自然历史博物馆（American Museum of Natural History）的演讲中提出：“你们谁能告诉我任何关于进化的真正证据，哪怕是一件真正的证据？”（”Can you tell me anything about evolution,” he asked his listeners, “any one thing, that is true?”）

1979年4月10日帕特森博士发给美国航空航天工程师路德‧桑德兰（Luther Sunderland, 1929—）一封信件，标题是：“没有任何一块化石能证明进化论！！”（Not one fossil of evidence fossil for evolution!!）内容摘录如下：

“你评论说我的书中缺乏对进化过渡的直接图示说明，我完全赞同。如果我知道任何化石或生物（能展示进化的过渡），我肯定已经把它们写在书中了。你建议应该请来一名画家将这些转变的过程视觉形象化，但他将从哪里获得这些信息？我无法诚实地提供出来，如果我让画家肆意发挥，这难道不会误导读者吗？……然而，当他们说不存在过渡性化石时，古尔德和美国博物馆的人都很难反驳。作为一名古生物学家，我非常忙于这些哲学问题，也就是在化石记录中识别祖先的形态。你说我至少应该‘展示一张有每种生物形态来源的化石照片’。我坦率地说──没有这样能令我们作无懈可击的论证的化石，因为有关祖先和遗传的陈述，并不适用于化石记录。”⁸⁰

（I fully agree with your comments on the lack of direct illustration of evolutionary transitions in my book. If I knew of any, fossil or living, I would certainly have include them. You suggest that an artist should be asked to visualize such transformations, but where would he get the information from? I could not honestly provide it, and if I were to leave it to artist licence, would not this mislead the reader?
……Yet Gould and the American Museum people are hard to contradict when they say there are no transitional fossils. As a paleontologist myself, I am much occupied with the philosophical problems of identifying ancestral forms in the fossil record. You say that I should at least “show a photo of the fossil from which each type of organism was derived.” I will lay it on the line – there is not one such fossil for which one could make a watertight argument. The reason is that statements about ancestry and descent are not applicable in the fossil record.）