La conferencia insular floras de Sir Joseph Hooker: el impacto humano y el paradigma del laboratorio natural (original) (raw)

Sir Joseph Hooker on Insular Floras: human impact and the natural laboratory paradigm

Scientia Insularum. Revista de Ciencias Naturales en islas, 2020

In 1866, the botanist Joseph Dalton Hooker (1817-1911) delivered a lecture to the British Association for the Advancement of Science in Nottingham, U.K. entitled Insular floras. The lecture has been described as "the first systematic statement of the importance of islands for evolutionary studies". As such, it can be seen to have contributed to the development of the "natural laboratory paradigm" that views islands as model systems for studying ecology and evolution. Hooker's lecture also highlighted another key driver in shaping island diversity patterns, namely human impact. How and when does human impact compromise the utility of islands as 'natural laboratories' for studying evolution? To date, no fewer than eight "shortfalls"-knowledge gaps that impact on studies of biodiversity-have been described. In this paper, we suggest that a further shortfall is in order-a Hookerian shortfall-to account for uncertainty in the extent to which biodiversity patterns reflect natural rather than anthropogenic processes.

Concluding remarks: historical perspective and the future of island biogeography theory

Global Ecology and Biogeography, 2000

MacArthur and Wilson's equilibrium theory revolutionized the field of island biogeography and, to a large degree, ecology as well. The theory, which quickly became the ruling paradigm of island biogeography, has changed little over the past three decades. It has not kept pace with relevant theory and our growing appreciation for the complexity of nature, especially with empirical findings that species diversity on many islands: 1) is not in equilibrium; 2) is influenced by differences in speciation, colonization, and extinction among taxa; and 3) is influenced by differences among islands in characteristics other than area and isolation. The discipline of biogeography, itself, is in a state of disequilibrium. We may again be about to witness another paradigm shift, which will see the replacement of MacArthur and Wilson's theory. Wherever this shift may take us, we are confident that the next generation of biogeographers will still look to islands for insights into the forces that shape biological diversity.

The human dimension of biodiversity changes on islands

Science, 2021

Accelerating ecosystem disruption Oceanic islands are among the most recent areas on Earth to have been colonized by humans, in many cases in just the past few thousand years. Therefore, they are important laboratories for the study of human impacts on natural vegetation and biodiversity. Nogué et al. provide a quantitative palaeoecological study of 27 islands around the world, focusing on pollen records of vegetation composition before and after human arrival. The authors found a consistent pattern of acceleration of vegetation turnover after human invasion, with median rates of change increasing by a factor of six. These changes occurred regardless of geographical and ecological features of the island and show how rapidly ecosystems can change and how island ecosystems are set on new trajectories. Science , this issue p. 488

A new golden era in island biogeography

For two centuries, islands have served as rich sources of inspiration and data for biogeographers, thus gaining renown as ideal natural laboratories. Their research potential continues to expand today thanks to the combined application of recent advances in several scientific fields. First, increasingly detailed geological and palaeoecological data are extending our understanding of the history of development of island biotas. At the same time, rapid methodological advances in molecular evolutionary biology and systematics are revealing the pathways by which species colonized islands, evolved, and formed communities. Third, basic data on species distributions are being collected from increasing numbers of islands and taxa, distributed widely through electronic resources, and analyzed with powerful software to reveal macroecological patterns. The pace and quality of recent advances signal a promising future in which islands will continue to play key roles in revealing how biodiversity is produced and maintained.

Cryptic introductions and the interpretation of island biodiversity

Molecular Ecology, 2013

Species with cryptic origins (i.e. those that cannot be reliably classed as native or nonnative) present a particular challenge to our understanding of the generation and maintenance of biodiversity. Such species may be especially common on islands given that some islands have had a relatively recent history of human settlement. It is likely that select island species considered native might have achieved their current distributions via direct or indirect human actions. As an example, we explore the origins of eastern bluebirds (Sialia sialis bermudensis) on the island of Bermuda. Considered native to the island and a distinct subspecies, this population has diverged in morphology relative to mainland North America. Using microsatellite markers and simulation of island colonization, we show that the Bermuda population of bluebirds is the likely result of a single colonization event that occurred during the 1600s, making this a cryptic invader. To our knowledge, this is one of the youngest examples of a terrestrial vertebrate cryptic invader. We suggest that the eastern bluebird is not an isolated case of cryptic invader on either Bermuda or elsewhere and that caution be exercised when studying present-day distributions of organisms.

The Reticulating Phylogeny of Island Biogeography Theory

The Quarterly Review of Biology, 2009

Biogeographers study all patterns in the geographic variation of life, from the spatial variation in genetic and physiological characteristics of cells and individuals, to the diversity and dynamics of biological communities among continental biotas or across oceanic archipelagoes. The field of island biogeography, in particular, has provided some genuinely transformative insights for the biological sciences, especially ecology and evolutionary biology. Our purpose here is to review the historical development of island biogeography theory during the 20th century by identifying the common threads that run through four sets of contributions made during this period, including those by Eugene Gordon Munroe (1948, 1953), Edward O. Wilson (1959, 1961), Frank W. Preston (1962a,b), and the seminal collaborations between Wilson and Robert H. MacArthur (1963, 1967), which revolutionized the field and served as its paradigm for nearly four decades. This epistemological account not only reviews the intriguing history of island theory, but it also includes fundamental lessons for advancing science through transformative integrations. Indeed, as is likely the case with many disciplines, island theory advanced not as a simple accumulation of facts and an orderly succession of theories and paradigms, but rather in fits and starts through a reticulating phylogeny of ideas and alternating periods of specialization and reintegration. We conclude this review with a summary of the salient features of this scientific revolution in the context of Kuhn's structure, which strongly influenced theoretical advances during this period, and we then describe some of the fundamental assumptions and tenets of an emerging reintegration of island biogeography theory.

A call for a new paradigm of island biogeography

Global Ecology and Biogeography, 2000

MacArthur and Wilson's equilibrium theory of island biogeography quickly became the paradigm of the field in the 1960s and has strongly influenced this and other disciplines of ecology and conservation biology for the past three decades. Recently, however, a growing number of ecologists have begun to question whether the theory remains a useful paradigm for modern ecology. We now have a much better appreciation for the complexity of nature and we study patterns that span a very broad range in spatial, temporal and ecological scales. At such scales, assumptions that communities are in equilibrium, that species, islands and intervening landscapes or seascapes are equivalent or homogeneous with respect to factors influencing immigration and extinction, and that in situ speciation can be overlooked become very tenuous. With this in mind, this and other papers of this special feature discuss the principal, conceptual shortcomings of the equilibrium theory and offer some modifications or alternatives to the theory that we hope will eventually lead to a more comprehensive understanding of the forces structuring insular communities.