Organisms [...] are directed and limited by their past. They must remain imperfect in their form and function, and to that extent unpredictable since… - Stephen Jay Gould

But our strong desire to identify trends often leads us to detect a directionality that doesn’t exist, or to infer causes that cannot be sustained. The subject of trends has inspired and illustrated some of the classic fallacies in human reasoning. Most prominently, since people seem to be so bad at thinking about probability and so prone to read pattern into sequence of events, we often commit the fallacy of spotting a “sure” trend in speculating about causes, when we observe no more than a random string of happenings.

Ordinary speciation remains fully adequate to explain the causes and phenomenology of punctuation.

If the neck of the giraffe elongates an inch at a time, then the full panoply of supporting structures need not arise at every step. The coordinated adaptation can be built piecemeal. Some animals may slightly elongate the neck, others the legs; still others may develop stronger neck muscles. By sexual reproduction, the favorable features of different organisms may be combined in offspring.