Any proposal to spend more time on a new subject is greeted with the quite reasonable objection, “but what will we eliminate in order to do that?” There will be howls, but here are some space-wasters that can easily go.
First of all, Lamarck. His worldview was really of another time, far more complex and nuanced than can be conveyed in a life science or biology text in the space available. What Lamarck thought—including his whole “system” of fluids governing all aspects of natural phenomena—is difficult to describe, and anyway, he was wrong and his ideas are almost forgotten. (Some years ago in Paris, I found that his Philosophie Zoologique was out of print.) His career and Darwin’s did not overlap, and each of them spent exactly one paragraph among thousands of printed pages on the neck of the giraffe; yet this example is trotted out in the vast majority of biology texts, as if they debated each other head-to-head. There is not a single textbook in America that gives an accurate account of what Lamarck was talking about. This is sufficient reason in itself to eliminate him from the books.
Second, species concepts. Each of them is only provisionally useful, and none embodies Darwin’s perspicacity in the first chapter of the Origin of Species (1859). Darwin recognized that naturalists, despite their confidence, could not make any universal statements that enabled others to determine what a species was, or to differentiate it from a subspecies, a genus, a race, or a variety. This is because lineages (to use a neutral term) are constantly in the process of diverging from each other and are at different stages in the process, so the divisions that we call races, subspecies, species, etc. are arbitrary points on a continuum. And moreover, different kinds of organisms speciate in different ways, so one species “concept” cannot fit all. Emphasize the ideas in the previous three sentences, and there is no need to wade through the morass of “species concepts.” Different “species concepts” provide helpful diagnoses of differences among species, but they distract attention from the process of speciation, and they should not be pitted against each other as exclusive alternatives.
Instead, the process of speciation, as it occurs in many ways in many different groups (genetically, ecologically, geographically) should be described and documented pluralistically. The formation of new species is the first step to macroevolutionary patterns and processes, so it is all the more germane to the thesis of this paper.
Third, superficial glosses on the history of life that take three pages and mostly recount an aleatory assortment of factoids about groups that “appeared” and “disappeared” along with climate changes that seemingly have magical causes. This pablum is of no conceivable use. A sensible annotated chart of geologic time can give an overview of the history of life; it has been standard since Richard Owen’s (1860) text Palaeontology. Use the rest of the space to document examples of how we know what we know about the evolution of some major groups and adaptations.
Fourth, Linnaeus and his classificatory system. Linnaeus had no classificatory philosophy;Footnote 5 his “Natural System” was an attempt to know the mind of the Creator, which is not a goal of modern science. He grouped by similarity and worked a century before the greatest idea in biology even began to be generally accepted. He invented some rank names and promoted the binominal system (unique genus and species name). But his influence on biological education has always been greater than it should be. In the Origin of Species, Darwin insisted that all classification should be based on genealogy—what we would call phylogenetic relationship. No one listened; they kept using Linnaeus’s system, so we had another century of taxonomic stagnation until that was reformed. Essentially all modern systematics is phylogenetic (cladistic), and the Linnean “ranks” such as Order and Class are nothing more than bookmarks with no biological comparability or meaning. They have outlived their utility, and it is a waste of space to rehearse Linnaeus’ history and system beyond the few facts above.
On the other hand, it is surprisingly useful to teach students phylogenetics before the units on evolution and diversity of life. All students have some experience with types of plants and animals, and they know that organisms are related to each other; they just don’t know how this is determined. Show them that part first, and then they can understand, for example, why we classify birds within the reptiles (instead of as a separate “Class”), and why we don’t classify even-toed and odd-toed hoofed mammals together (as “Ungulata”), even though they have hooves.