Systematics and the study of natural history, with an estimate of the phylogeny of the living penguins (Aves:Spheniscidae)
Chapter 1. Evolutionary biology is an historical science, and should be considered within the context of the philosophy of history, not the philosophy of science. Just as philosophers of history distinguish between chronicle and narrative history, I distinguish between evolutionary chronicle and narrative evolutionary history. Systematics estimates the evolutionary chronicle.
Explanations of the events in the evolutionary chronicle are of the how-possibly, continuous series, and integrating types described by philosophers of history. Pre-evolutionary explanations of states (in contrast to events) are still widespread in "evolutionary" biology because evolutionary chronicles are poorly known. To the extent that chronicles are known, the evolutionary narratives based on them are structured like conventional historical narratives, treating their central subjects as ontological individuals, instead of as clades, which have some of the properties of individuals and some of the properties of classes. The treatment of clades as narrative individuals has been the cause of erroneous notions of evolutionary progress, and of views that taxa "develop" in ways analogous to individual organisms.
Chapter 2. Cladistic analysis has brought about a revolution in systematics. Most reviews of systematic literature fail to discuss the theoretical views of earlier authors, and so are of little value as history or as science.
Cladistic analysis of 23 ordered, equally weighted characters of 14 of the 16 species of penguins (Aves: Speniscidae) yields six unrooted minimal-length networks of 67 steps (C.I. = 0.627) of which this is a strict consensus: (((Aptenodytes patagonicus, A. forsteri), (Pygoscelis adeliae, P. antarctica, P. papua)), ((Eudyptes chrysocome, (Eudyptes chrysolophus, Eudyptes pachyrhynchus)), (Megadyptes antipodes, (Eudyptula minor, (Spheniscus demersus, S. magellanicus, S. humboldti, S. mendiculus))))). Four outgroups, considered individually, root this network in three different places, but do not change its structure. Diomedea exulans and Fregata magnificens root it at the base of the Spheniscus polychotomy; Gavia immer between Aptenodytes+Pygoscelis and the other genera; and Podilymbus podiceps between Aptenodytes and the other genera.