Islands as Evolutionary Laboratories

by

Anna Holmquist, Rosemary G. Gillespie

• LAST REVIEWED: 24 March 2021
• LAST MODIFIED: 24 March 2021
• DOI: 10.1093/obo/9780199941728-0134

Introduction

Islands have inspired biologists for hundreds of years as locations that foster unique biotic assemblages and provide insights into ecological and evolutionary processes dictating life globally. Although by classic definition islands are subcontinental land masses surrounded by water, from a biological perspective, islands can be defined broadly as any isolated piece of habitat that is surrounded by distinct environmental conditions. Therefore the study of island biology applies to any area that is habitable for a given set of organisms and is separated from a source by an inhospitable matrix. Biological islands can include lakes surrounded by land and mountaintops, caves, and land fragments surrounded by habitat in which an organism of interest cannot survive or reproduce. Given sufficient isolation, these attributes can result in a distinctive biota.

General Overviews

Numerous books and review papers have been published on island biology and evolution. The first concise account is Wallace 1880; writings of the prolific Alfred Russell Wallace are both foundational to evolutionary biology and island biogeography as well as captivating reads despite their age. In recent years, an increasing number of compilations have been published, including Carlquist 1974, Grant 1998, MacArthur and Wilson 1967, Whittaker and Fernández-Palacios 2007, and Gillespie and Clague 2009. Each serves as an excellent resource for those in search of thorough overviews of island systems.

• Carlquist, S. J. 1974. Island biology. New York: Columbia Univ. Press.

  Covers general dynamics of islands, with an emphasis on botanical patterns of oceanic islands. The first chapter explores island dispersal and evolution, with subsequent chapters covering adaptive radiation across different island systems. The text provides a succinct overview of essential principles involved in the evolution of island biota.

• Gillespie, R. G., and D. A. Clague, eds. 2009. Encyclopedia of islands. Oakland: Univ. of California Press.

  Refence text covering topics related to islands, written by experts globally. Chapters cover individual island systems, consisting of paired chapters covering the biological understanding and geological perspective of each system. Additional chapters focus on specific animal and plant groups that are well studied on islands as well as special attributes of islands, including characteristic geological and climatological conditions.

• Grant, P. R., ed. 1998. Evolution on islands: Originating from contributions to a discussion meeting of the Royal society of London held Dec. 1995. Oxford: Oxford Univ. Press.

  This is a compilation from numerous authors covering evolutionary patterns and processes observed on islands across various taxonomic groups and systems. It provides a diversity of research focused on topics of island evolution, including speciation, hybridization, and genetic drift.

• MacArthur, R. H., and E. O. Wilson. 1967. The theory of island biogeography. Princeton, NJ: Princeton Univ. Press.

  Leading to a major paradigm shift in ecology, MacArthur and Wilson proposed that islands maintain a dynamic equilibrium through a balance of immigration and extinction, both of which are tightly related to the area of the island and degree of isolation. Island biogeography theory is considered one of the essential theories of biogeography and ecology and has been applied broadly to understand dynamics of habitat islands and land fragments.

• Wallace, A. R. 1880. Island life, or The phenomena and causes of insular faunas and floras, including a revision and attempted solution to the problem of geological climates. London: Macmillan.

  DOI: 10.5962/bhl.title.98129

  The book is divided into two parts, the first highlighting ties between geology, climate, and landscape features in dictating the distribution of organisms. The second part of the book describes the importance of islands, with specific illustrations provided by oceanic islands and continental islands. For each island group, there is discussion of how the floras and faunas have evolved.

• Whittaker, R. J., and J. M. Fernández-Palacios. 2007. Island biogeography: Ecology, evolution, and conservation. Oxford: Oxford Univ. Press.

  A thorough text covering a broad range of topics essential to island studies. The main sections cover an overview of island systems, island ecology, evolution on islands, and island conservation in the face of human change.