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By way of introduction, this short piece describes a few subjects that attracted Chris Humphries's attention during his thirty-plus years as botanist and systematist. These include botanical cladistics, cladistics and daisies, and biogeographic cladistics. Humphries joined the Department of Botany of the Natural History Museum in 1972 replacing Alexsandr Melderis, then head of the European Herbarium. His first task was to finish his thesis and obtain his PhD degree, which he did in 1973. His study was on species of Argyranthemum, a genus of daisy in the family Asteraceae, and is a fine example of a morphological investigation (with a little phytochemistry) and anatomical interpretation, with comments on their relationships and geographic distribution. Humphries's studies on Asteraceae to one side, the next period in his career focused almost exclusively on biogeography, and in 1979 he published his first considered paper on the subject, “Endemism and Evolution in Macaronesia.” Humphries blazed a trail for botany at the Natural History Museum and beyond — and his influence extended to other museum departments.

The various contributions that Chris Humphries made to the biodiversity conservation movement during the early 1990s were literally and severally “rooted in cladistics.” Soon after finishing his PhD, Humphries arrived in the Botany Department of the Natural History Museum, London. At that time, the author was very interested in coevolution — he wanted to try to understand the evolution of mimicry by comparing cladograms for mimetic butterflies, their models, and their host plants. Humphries's contributions to what became cladistics soon far outstripped the author's own — and have done so ever since. Humphries and the author got together right at the end of the 1980s, to refine and develop the notion of “critical faunas analysis.” The two men felt they had the beginnings of what Robert May (1990) called for: a “calculus of biodiversity.” Humphries proposed a variant in which terms and components were combined to reflect, very simply and elegantly, the number of taxonomic statements that could be made about each terminal taxon represented in a cladogram (or hierarchical classification).

This Festschrift for Chris Humphries provides an opportunity to reflect on how much has changed in systematic biology since the 1970s. Humphries, together with his longtime collaborator, Kåre Bremer, pioneered the application of cladistic methods of phylogeny reconstruction in the Compositae and soon influenced the systematics of other groups of living and fossil plants. Today, the classification of the Compositae has been turned literally upside-down thanks to the availability of DNA sequence characters and the almost universally adopted procedures of phylogenetic systematics. There can be little doubt that Humphries's pivotal role in the promotion of cladistics was greatly enhanced by his appointment to the Department of Botany at the (then) British Museum (Natural History). This chapter focuses on Humphries's contribution to the field of evolution and development. It considers how the field of ontogeny and systematics has developed through to the present day, with particular emphasis on pollen ontogeny. It concluded that Humphries played an influential role in the emergence of the discipline now recognized as “evo-devo”: evolutionary developmental biology.

The Macaronesian region comprises the volcanic oceanic archipelagos of the Azores, Madeira, Salvages, Canary Islands, and Cape Verdes located in the North Atlantic Ocean. The flora of the region demonstrate many characteristics typical of oceanic archipelago floras, notably a high degree of endemism. Argyranthemum (Compositae), the subject of Chris Humphries's doctoral research, provides an excellent example of island evolution in the region. Endemic to Macaronesia, Argyranthemum comprises twenty-four species of woody perennials. Molecular data support the monophyly and radiation of the genus in the region and indicate that its closest relatives are herbaceous and distributed in North Africa. This chapter examines the impact of cladistics on our understanding of the Macaronesian flora. It considers the biogeographic relationships of Macaronesian plant groups and the impact of cladistic analyses, together with other analyses of regional diversity patterns, on our understanding of patterns of intraregional radiations. Finally, it discusses the distinctive growth form spectrum of Macaronesian endemic plants and presents a preliminary evaluation of the extent to which woodiness in Macaronesia may be associated with insularity and linked to intraregional diversification.

Wallacea is a triangular-shaped area in the middle of the Indo-Australian Archipelago that was delimited by Roy Ernest Dickerson and colleagues (1928) in a collaborative volume on the distribution of plants and animals of the Philippine Archipelago. Chris Humphries pointed out that a rigorous analysis that proposed a testable hypothesis of area relationships, an area classification, was needed but had never been executed. To Humphries, Wallacea was part of the descriptive and narrative phase of biogeography. The analytical phase of biogeography in which areas are defined and diagnosed rigorously and testable hypotheses of relationships among areas are proposed had yet to be broached. The Sunda Shelf (west of Wallace's Line) and the Sahul Shelf (east of Weber's Line) were home to readily identifiable endemic biotas. Humphries posed a three-area problem: what are the relationships among Wallacaea, Sundaland, and Papualand? The basic units of biogeographic analysis should be areas of endemism — areas circumscribed by taxa, not solely geography. This chapter also looks at the monophyly of Wallacea and the systematic biogeography of Subregion A.

Ernest Rutherford was more candid about his bias than most experimental biologists are in sharing their view of taxonomy. Experimental biologists do want to collect every species, but the similarity stops there. Their motive is to explore unique characters and all their subsequent modifications through evolutionary history, to determine what they mean in terms of species, relative recency of common ancestry among species, and as the basis for informative and predictive classifications. Taxonomists ask some of the most basic, important, and interesting questions about biodiversity: What are species? What species exist? What is the history of the origin and transformation of their characters? What are their phylogenetic relationships? What are their distributions? And how are they predictively and most informatively classified? Chris Humphries has made superb descriptive taxonomic and anatomical contributions, advanced the theories needed to analyze characters and complete cladistic analyses, proposed innovative tools to use evolutionary history to set conservation priorities, transformed historical biogeography, and served as a constant source of support and encouragement to his colleagues and generations of students.

The Macaronesian islands were an early place of interaction between European botanists and a spectacular flora characterized by high levels of endemism. In 1992, a project was launched to investigate the extent to which the flora of Macaronesia was known among pre-Linnaean botanists from Britain. This chapter reviews the major findings from that study. The main conclusion of this research is that these collections represent some of the most important milestones in the history of natural history of Macaronesia. It argues that these early studies helped to establish the Macaronesian islands as a resource for British horticultural collectors and as a scientific arena that ultimately, via the activities of authorities such as Hans Sloane, Alexander Von Humboldt, and Charles Darwin, created a pivotal role for islands in studies of biogeography and evolution, and subsequently in the development of conservation as a quantitative science. This chapter pays homage to Chris Humphries and is a celebration of the great tradition of synergy among horticulture, systematics, and field botany that has so characterized the study of the Macaronesian flora.