Taxonomic diversity of island biotas.
TL;DR: In this paper, the authors studied the distribution of the mean number of species per genus (S/G) on an island is usually lower than S/G for its presumed source area (MacArthur and Wilson, 1967).
Abstract: Students of biogeography since Darwin have focused disproportionately on oceanic islands. The prime bases for this interest have been the distinct forms which have evolved in the genetic isolation provided by islands and the ecological situation pertaining because the species successfully colonizing any island are but a small subset of the mainland species pool. One aspect of the latter effect which has received attention is that, within any higher taxon, the mean number of species per genus (S/G) on an island is usually lower than S/G for its presumed source area (MacArthur and Wilson, 1967). If it is assumed that congeneric species tend to resemble one another more in any measurable biological characteristic than do less closely related species, then the lower S/G on an island implies a more "diverse" biota on the island than on the source area. Although Williams (1964) pointed out that a random subset of any species pool has an expected S/G lower than that of the entire pool, Moreau (1966) and Grant (1966) attach significance to the lower S/G per se on islands, without regard for whether this S/G is lower or higher than expected, and attribute the lower insular value to ecological and/or evolutionary phenomena. In this paper I will first treat qualitatively the general distribution of the S/G ratio for random subsets of any species pool, then analyze the data for a series of well-studied island groups, and finally reassess the ecological and evolutionary ideas formulated on this subject in the light of the statistical treatment. THEORETICAL CONSIDERATIONS
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
TL;DR: A series of common pitfalls in quantifying and comparing taxon richness are surveyed, including category‐subcategory ratios (species-to-genus and species-toindividual ratios) and rarefaction methods, which allow for meaningful standardization and comparison of datasets.
Abstract: Species richness is a fundamental measurement of community and regional diversity, and it underlies many ecological models and conservation strategies. In spite of its importance, ecologists have not always appreciated the effects of abundance and sampling effort on richness measures and comparisons. We survey a series of common pitfalls in quantifying and comparing taxon richness. These pitfalls can be largely avoided by using accumulation and rarefaction curves, which may be based on either individuals or samples. These taxon sampling curves contain the basic information for valid richness comparisons, including category‐subcategory ratios (species-to-genus and species-toindividual ratios). Rarefaction methods ‐ both sample-based and individual-based ‐ allow for meaningful standardization and comparison of datasets. Standardizing data sets by area or sampling effort may produce very different results compared to standardizing by number of individuals collected, and it is not always clear which measure of diversity is more appropriate. Asymptotic richness estimators provide lower-bound estimates for taxon-rich groups such as tropical arthropods, in which observed richness rarely reaches an asymptote, despite intensive sampling. Recent examples of diversity studies of tropical trees, stream invertebrates, and herbaceous plants emphasize the importance of carefully quantifying species richness using taxon sampling curves.
5,706 citations
Cites background from "Taxonomic diversity of island biota..."
...Although their work was ignored by ecologists for several decades (Ja ¨rvinen 1982), re-analyses of species-to-genus ratios now suggest that island communities harbour slightly more species per genus than expected by chance, in spite of the lower absolute number of species per genus expected in smaller samples ( Simberloff 1970 )....
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...However, subtaxon‐taxon ratios are an increasing function of sample size, and would be expected to decrease in small communities, regardless of the level of competition (Williams 1947, 1964; Simberloff 1970, 1972 )....
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...The species-to-genus ratio has long been used to describe community patterns and to infer levels of competitive interactions among species within genera (reviews in Simberloff 1970; Ja ¨rvinen 1982)....
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...However, subtaxon±taxon ratios are an increasing function of sample size, and would be expected to decrease in small communities, regardless of the level of competition (Williams 1947, 1964; Simberloff 1970, 1972)....
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...…by ecologists for several decades (JaÈrvinen 1982), re-analyses of species-to-genus ratios now suggest that island communities harbour slightly more species per genus than expected by chance, in spite of the lower absolute number of species per genus expected in smaller samples (Simberloff 1970)....
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TL;DR: A common pattern of phylogenetic conservatism in ecological character is recognized and the challenges of using phylogenies of partial lineages are highlighted and phylogenetic approaches to three emergent properties of communities: species diversity, relative abundance distributions, and range sizes are reviewed.
Abstract: ▪ Abstract As better phylogenetic hypotheses become available for many groups of organisms, studies in community ecology can be informed by knowledge of the evolutionary relationships among coexisting species. We note three primary approaches to integrating phylogenetic information into studies of community organization: 1. examining the phylogenetic structure of community assemblages, 2. exploring the phylogenetic basis of community niche structure, and 3. adding a community context to studies of trait evolution and biogeography. We recognize a common pattern of phylogenetic conservatism in ecological character and highlight the challenges of using phylogenies of partial lineages. We also review phylogenetic approaches to three emergent properties of communities: species diversity, relative abundance distributions, and range sizes. Methodological advances in phylogenetic supertree construction, character reconstruction, null models for community assembly and character evolution, and metrics of community ...
3,615 citations
Cites background from "Taxonomic diversity of island biota..."
...Interest continued in species/genus ratios for a number of years (Moreau 1948, Williams 1964, Simberloff 1970, Tokeshi 1991) and was notable as the context for the first use of null models in ecology (Gotelli & Graves 1996)....
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TL;DR: It is proposed that the exponential and power function models of the species-area relationship result from the way in which individuals are distributed among species, and specific values of the slope of the power function are often construed to * Order of authorship determined by the toss of a coin.
Abstract: Regional differences in species number have puzzled naturalists ince the early 1800's, and explanations account for a large part of modern ecological research. Two venerable observations form the cornerstone of our knowledge on the subject: The number of species within a taxonomic group tends to increase with decreasing latitude (see Fischer 1960; Pianka 1966); and the number of species within a taxonomic group tends to increase with increasing area (see Preston 1960, 1962; Williams 1964; MacArthur and Wilson 1967; Simberloff 1972). Despite early research on the latter trend (the species-area relationship), ecologists have studied it intensely only in the last 50 yr. The relationship was originally envisioned as an empirical tool and used in three principle ways: (1) to determine optimal sample size and sample number, (2) to determine the minimum area of a \"community,\" and (3) to predict the number of species in areas larger than those sampled. All three uses are discussed by Kilburn (1966). More recently interest in the species-area relationship has focused on mechanistic explanations, its precise mathematical descriptions, and interpretations of parameters derived from these mathematical descriptions. Williams (1964) and Preston (1960, 1962) have proposed that the exponential and power function models (\"exponential model\" throughout his paper also refers to the species/log area transformation, and \"power function\" also refers to the log species/log area transformation) of the species-area relationship result from the way in which individuals are distributed among species. Williams' (1964) exponential model, which emphasizes habitat heterogeneity, was considered important by many plant ecologists but is now largely ignored. Preston's (1960, 1962) power function model was based on the assumption of a dynamic equilibrium of species exchanges between islands in an archipelago. This assumption led to the equation of the power function model with the idea of a dynamic equilibrium as expounded by MacArthur and Wilson (1963, 1967), such that an adequate fit of this model to observed species numbers has been viewed as support of the equilibrium hypothesis (Grant 1970; Diamond 1973; Simpson 1974). The interplay of the equilibrium hypothesis and the power function model of the species-area relationship has led to interpretation of the slope and intercept of the power function model exclusively in the context of the equilibrium hypothesis. In particular, specific values of the slope of the power function are often construed to * Order of authorship determined by the toss of a coin. t Present address: Department of Biology, University of South Florida, Tampa, Florida 33620. Am. Nat. 1979. Vol. 113, pp. 791-833. c) 1979 by The University of Chicago. 0003-0147/79/1306-0002$03.26
2,083 citations
TL;DR: Several key areas are reviewed in which phylogenetic information helps to resolve long-standing controversies in community ecology, challenges previous assumptions, and opens new areas of investigation.
Abstract: The increasing availability of phylogenetic data, computing power and informatics tools has facilitated a rapid expansion of studies that apply phylogenetic data and methods to community ecology. Several key areas are reviewed in which phylogenetic information helps to resolve long-standing controversies in community ecology, challenges previous assumptions, and opens new areas of investigation. In particular, studies in phylogenetic community ecology have helped to reveal the multitude of processes driving community assembly and have demonstrated the importance of evolution in the assembly process. Phylogenetic approaches have also increased understanding of the consequences of community interactions for speciation, adaptation and extinction. Finally, phylogenetic community structure and composition holds promise for predicting ecosystem processes and impacts of global change. Major challenges to advancing these areas remain. In particular, determining the extent to which ecologically relevant traits are phylogenetically conserved or convergent, and over what temporal scale, is critical to understanding the causes of community phylogenetic structure and its evolutionary and ecosystem consequences. Harnessing phylogenetic information to understand and forecast changes in diversity and dynamics of communities is a critical step in managing and restoring the Earths biota in a time of rapid global change.
1,867 citations
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
Book•
01 Jan 1967
TL;DR: The Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
12,546 citations
Book•
01 Jan 1919
TL;DR: A comprehensive and indispensable reference to the generic and family names of flowering plants and ferns can be found in the 8th edition of the Dictionary of Ferns as discussed by the authors.
Abstract: Willis's Dictionary is a famous publication in the world of botany and horticulture It is a comprehensive and indispensable reference to the generic and family names of flowering plants and ferns The entries attempt to cover all published generic names from 1753 onwards and published family names from 1789, together with a number of supra- and infra-familial taxa where these have not been based on family or generic names The generic names include many variant spellings and inter-generic hybrids Brief characters of subfamilies are usually given The treatment of the families and higher taxa of the Pteridophyta is based on the classification scheme proposed by Pichi-Sermolli The synopses of the Bentham & Hooker and Engler & Prand systems are retained This eighth edition is now published in paperback in order to make it available to a wider readership, not only of professional botanists, but also students and serious amateurs
1,203 citations
Book•
10 Aug 2011
TL;DR: The following rule is predicted: the ecological amplitude of individual species, both expanding and endemic, should be negatively correlated with the size of the local fauna to which they belong and hence thesize of the island on which they occur.
Abstract: Undisturbed ant faunas of islands in the Moluccas-Melanesian arc are for the most part "saturated," that is, approach a size that is correlated closely with the landmass of the island but only weakly with its geographic location (figure 1). In the Ponerinae and Cerapachyinae combined the saturation level can be expressed approximately as F=3A0.6, where F is the number of species in the fauna and A the area of the island in square miles. Interspecific competition, involving some degree of colonial warfare, plays a major role in the determination of the saturation curve. It deploys the distribution of some ant species into mosaic patterns and increases the diversification of local faunas. Perhaps because of the complex nature of the Melanesian fauna, differences between local faunas appear that give the subjective impression of randomness. Despite the action of species exclusion, the size of local faunas occurring within a set sample area increases with the total size of the island (figure 2). Water gaps br...
524 citations