The original letter:

The coverage of the "fishapod" presented in "Our Cousin the Fishapod" was excellent, the importance of the discovery was presented with clarity. However, there is a fundamental flaw present in the presentation of evolutionary pathways that engenders confusion for people on all sides of this problem. The concept of species is inherently problematic, as there is no conventional definition for what it entails. This is the result of applying a classification scheme to what is essentially a continuous process, which gives the impression of significant changes having occurred in the span of a single generation. This is exactly the misunderstanding that is often used by anti-evolutionists as a counter-argument. If species are regarded as being static entities, then the first of one species must be the offspring of an entirely different species. This is not the reality. Species are snapshots that represent a lineage at convenient points, be it the present or at a time where we have an example in the fossil record. The concept of species facilitates discussion and study, but it is a purely human construct, much like time itself. Every child has differences from its parents, and over a great number of generations some changes will spread through a population due to selective breeding. The "fishapod" is a valuable find as a missing link, which is another snapshot in a continuum of change. Understanding that such changes are constant and that what we refer to as a species is a dynamic entity encompassing significant variation should help people find common ground on the controversy of evolution.